Cactus 4.11
Reference Manual

commit f0cd488f6117286b5ccfc0f998ff4ef1f632a27e
Documentation compiled on: March 29, 2022

Preface

This document will eventually be a complete reference manual for the Cactus Code. However, it is currently under development, so please be patient if you can’t find what you need. Please report omissions, errors, or suggestions to and of our contact addresses below, and we will try and fix them as soon as possible.

Overview of documentation

This guide covers the following topics

Part A: CCTK_* Function Reference.

Here all the CCTK_*() Cactus flesh functions which are available to thorn writers are described.

Part B: Util_* Function Reference.

Here all the Util_*() Cactus flesh functions which are available to thorn writers are described.

Part C: Driver_* Function Reference.

Here all the Driver_*() functions which a Driver may make available to thorn writers are described.

Other topics to be discussed in separate documents include:

Users’ Guide

This gives a general overview of the Cactus Computational Tool Kit, including overall design/architecture, how to get/configure/compile/run it, and general discussions of the how to program in Cactus.

Relativity Thorn Guide

This will contain details about the arrangements and thorns making up the Cactus Relativity Tool Kit, one of the major motivators, and still the driving force, for the Cactus Code.

Flesh Maintainers Guide

This will contain all the gruesome details about the inner workings of Cactus, for all those who want or need to expand or maintain the core of Cactus.

Typographical Conventions

Typewriter

Is currently used for everything you type, for program names, and code extracts.

< ... >

Indicates a compulsory argument.

[ ... ]

Indicates an optional argument.

|

Indicates an exclusive or.

Please let us know of any errors or omissions in this guide, as well as suggestions for future editions. These can be reported via cactusmaint@cactuscode.org.

Acknowledgements

Hearty thanks to all those who have helped with documentation for the Cactus Code. Special thanks to those who struggled with the earliest sparse versions of this guide and sent in mistakes and suggestions, in particular John Baker, Carsten Gundlach, Ginny Hudak-David, Sai Iyer, Paul Lamping, Nancy Tran and Ed Seidel.

# Part ACCTK_* Functions Reference

In this chapter all CCTK_* Cactus functions are described. These functions are callable from Fortran or C thorns. Note that whereas all functions are available from C, not all are currently available from Fortran.

## Chapter A1Functions Alphabetically

CCTK_Abort

[A27] Causes abnormal Cactus termination

CCTK_ActivatingThorn

[A32] Finds the thorn which activated a particular implementation

CCTK_ActiveTimeLevels

[A34] Returns the number of active timelevels from a group name

CCTK_ActiveTimeLevelsGI

[A34] Returns the number of active timelevels from a group index

CCTK_ActiveTimeLevelsGN

[A34] Returns the number of active timelevels from a group name

CCTK_ActiveTimeLevelsVI

[A34] Returns the number of active timelevels from a variable index

CCTK_ActiveTimeLevelsVN

[A34] Returns the number of active timelevels from a variable name

CCTK_ArrayGroupSize

[A37] Returns a pointer to the local size for a group, given by its group name

CCTK_ArrayGroupSizeI

[A40] Returns a pointer to the local size for a group, given by its group index

CCTK_Barrier

[A42] Synchronizes all processors

CCTK_ClockRegister

[A44] Registers a new named clock with the Flesh.

CCTK_Cmplx

[A45] Turns two real numbers into a complex number (only C) [deprecated]

CCTK_CmplxAbs

[A48] Returns the absolute value of a complex number (only C) [deprecated]

[A50] Returns the sum of two complex numbers (only C) [deprecated]

CCTK_CmplxConjg

[A52] Returns the complex conjugate of a complex number (only C) [deprecated]

CCTK_CmplxCos

[A54] Returns the Cosine of a complex number (only C) [deprecated]

CCTK_CmplxDiv

[A56] Returns the division of two complex numbers (only C) [deprecated]

CCTK_CmplxExp

[A58] Returns the Exponentiation of a complex number (only C) [deprecated]

CCTK_CmplxImag

[A60] Returns the imaginary part of a complex number (only C) [deprecated]

CCTK_CmplxLog

[A62] Returns the Logarithm of a complex number (only C) [deprecated]

CCTK_CmplxMul

[A64] Returns the multiplication of two complex numbers (only C) [deprecated]

CCTK_CmplxReal

[A66] Returns the real part of a complex number (only C) [deprecated]

CCTK_CmplxSin

[A68] Returns the Sine of a complex number (only C) [deprecated]

CCTK_CmplxSqrt

[A70] Returns the square root of a complex number (only C) [deprecated]

CCTK_CmplxSub

[A72] Returns the subtraction of two complex numbers (only C) [deprecated]

CCTK_CommandLine

[A74] Gets the command line arguments.

CCTK_CompileDate

[A75] Returns a formatted string containing the date stamp when Cactus was compiled

CCTK_CompileDateTime

[A76] Returns a formatted string containing the datetime stamp when Cactus was compiled

CCTK_CompileTime

[A77] Returns a formatted string containing the time stamp when Cactus was compiled

CCTK_CompiledImplementation

[A79] Return the name of the compiled implementation with given index

CCTK_CompiledThorn

[A81] Return the name of the compiled thorn with given index

CCTK_CoordDir

[A83] Give the direction for a given coordinate name (deprecated)

CCTK_CoordIndex

[A87] Give the grid variable index for a given coordinate (deprecated)

CCTK_CoordRange

[A91] Return the global upper and lower bounds for a given coordinate name on a cctkGH (deprecated)

CCTK_CoordRegisterData

[A95] Register a coordinate as belonging to a coordinate system, with a given name and direction, and optionally with a grid variable (deprecated)

CCTK_CoordRegisterRange

[A99] Saves the global upper and lower bounds for a given coordinate name on a cctkGH (deprecated)

CCTK_CoordRegisterSystem

[A103] Registers a coordinate system with a given dimension (deprecated)

CCTK_CoordSystemDim

[A107] Provides the dimension of a given coordinate system (deprecated)

CCTK_CoordSystemHandle

[A111] Get the handle associated with a registered coordinate system (deprecated)

CCTK_CoordSystemName

[A115] Provides the name of the coordinate system identified by its handle (deprecated)

CCTK_CreateDirectory

[A117] Creates a directory

CCTK_DeclaredTimeLevels

[A121] Gives the maximum number of timelevels for a group

CCTK_DeclaredTimeLevelsGI

[A125] Gives the maximum number of timelevels for a group

CCTK_DeclaredTimeLevelsGN

[A129] Gives the maximum number of timelevels for a group

CCTK_DeclaredTimeLevelsVI

[A130] Gives the maximum number of timelevels for a variable

CCTK_DeclaredTimeLevelsVN

[A134] Gives the maximum number of timelevels for a variable

CCTK_DecomposeName

[A138] Given the full name of a variable/group, separates the name returning both the implementation and the variable/group

CCTK_DisableGroupComm

[A140] Disable the communication for a group

CCTK_DisableGroupCommI

[A141] Disable the communication for a group

CCTK_DisableGroupStorage

[A143] Disable the storage for a group

CCTK_DisableGroupStorageI

[A144] Disable the storage for a group

CCTK_EnableGroupComm

[A145] Enable the communication for a group

CCTK_EnableGroupCommI

[A147] Enable the communication for a group

CCTK_EnableGroupStorage

[A149] Enable the storage for a group

CCTK_EnableGroupStorageI

[A150] Enable the storage for a group

CCTK_Equals

[A152] Check a STRING or KEYWORD parameter for equality equality with a given string

CCTK_ERROR

[A158] Macro to print a single string as error message to standard error and stop the code

CCTK_Error

[A163] Function to print a single string as error message to standard error and stop the code

CCTK_Exit

[A166] Causes normal Cactus termination

CCTK_FirstVarIndex

[A169] Given a group name returns the first variable index in the group

CCTK_FirstVarIndexI

[A172] Given a group index returns the first variable index in the group

CCTK_FortranString

[A175] Copy the contents of a C string into a Fortran string variable

CCTK_FullGroupName

[A179] Given a group index, returns the group name

CCTK_FullName

[A184] Given a variable index, returns the full name of the variable

CCTK_FullVarName

[A181] Given a variable index, returns the full name of the variable

CCTK_GetClockName

[A187] Given a pointer to a clock cTimerVal structure, returns the name of the clock.

CCTK_GetClockResolution

[A188] Given a pointer to a clock cTimerVal structure, returns the resolution of the clock.

CCTK_GetClockSeconds

[A189] Given a pointer to a clock cTimerVal structure, returns the elapsed time.

CCTK_GetClockValue

[A190] Given the name of a clock, returns a pointer to the corresponding cTimerVal structure within the cTimerData structure.

CCTK_GetClockValueI

[A191] Given the index of a clock, returns a pointer to the corresponding cTimerVal structure within the cTimerData structure.

CCTK_GFINDEX1D

[A193] Given a set of multidimensional indices compute the 1-dimensional index into a grid function.

CCTK_GFINDEX2D

[A195] Given a set of multidimensional indices compute the 2-dimensional index into a grid function.

CCTK_GFINDEX3D

[A197] Given a set of multidimensional indices compute the 3-dimensional index into a grid function.

CCTK_GFINDEX4D

[A199] Given a set of multidimensional indices compute the 4-dimensional index into a grid function.

CCTK_GHExtension

[A201] Get the pointer to a registered extension to the Cactus GH structure

CCTK_GHExtensionHandle

[A203] Get the handle associated with a extension to the Cactus GH structure

CCTK_GridArrayReductionOperator

[A207] The name of the implementation of a grid array reduction operator, or NULL if the handle is invalid

CCTK_GroupbboxGI

[A209] Given a group index, return an array of the bounding box of the group for each face

CCTK_GroupbboxGN

[A209] Given a group name, return an array of the bounding box of the group for each face

CCTK_GroupbboxVI

[A212] Given a variable index, return an array of the bounding box of the variable for each face

CCTK_GroupbboxVN

[A212] Given a variable name, return an array of the bounding box of the variable for each face

CCTK_GroupData

[A215] Given a group index, returns information about the variables held in the group

CCTK_GroupDimFromVarI

[A219] Given a variable index, returns the dimension of all variables in the group associated with this variable

CCTK_GroupDimI

[A222] Given a group index, returns the dimension of variables in that group

CCTK_GroupDynamicData

[A225] Given a group index, returns information about the variables held in the group

CCTK_GroupGhostsizesI

[A227] Given a group index, returns the ghost size array of that group

CCTK_GroupgshGI

[A230] Given a group index, return an array of the global size of the group in each dimension

CCTK_GroupgshGN

[A230] Given a group name, return an array of the global size of the group in each dimension

CCTK_GroupgshVI

[A233] Given a variable index, return an array of the global size of the variable in each dimension

CCTK_GroupgshVN

[A233] Given a variable name, return an array of the global size of the variable in each dimension

CCTK_GroupIndex

[A236] Get the index number for a group name

CCTK_GroupIndexFromVar

[A240] Given a variable name, returns the index of the associated group

CCTK_GroupIndexFromVarI

[A244] Given a variable index, returns the index of the associated group

CCTK_GrouplbndGI

[A248] Given a group index, return an array of the lower bounds of the group in each dimension

CCTK_GrouplbndGN

[A248] Given a group name, return an array of the lower bounds of the group in each dimension

CCTK_GrouplbndVI

[A251] Given a variable index, return an array of the lower bounds of the variable in each dimension

CCTK_GrouplbndVN

[A251] Given a variable name, return an array of the lower bounds of the variable in each dimension

CCTK_GrouplshGI

[A254] Given a group index, return an array of the local size of the group in each dimension

CCTK_GrouplshGN

[A254] Given a group name, return an array of the local size of the group in each dimension

CCTK_GrouplshVI

[A257] Given a variable index, return an array of the local size of the variable in each dimension

CCTK_GrouplshVN

[A257] Given a variable name, return an array of the local size of the variable in each dimension

CCTK_GroupashGI

[A260] Given a group index, return an array of the local allocated size of the group in each dimension

CCTK_GroupashGN

[A260] Given a group name, return an array of the local allocated size of the group in each dimension

CCTK_GroupashVI

[A263] Given a variable index, return an array of the local allocated size of the variable in each dimension

CCTK_GroupashVN

[A263] Given a variable name, return an array of the local allocated size of the variable in each dimension

CCTK_GroupName

[A266] Given a group index, returns the group name

CCTK_GroupNameFromVarI

[A268] Given a variable index, return the name of the associated group

CCTK_GroupnghostzonesGI

[A270] Given a group index, return an array with the number of ghostzones in each dimension of the group

CCTK_GroupnghostzonesGN

[A270] Given a group name, return an array with the number of ghostzones in each dimension of the group

CCTK_GroupnghostzonesVI

[A273] Given a variable index, return an array with the number of ghostzones in each dimension of the variable’s group

CCTK_GroupnghostzonesVN

[A273] Given a group variable, return an array with the number of ghostzones in each dimension of the variable’s group

CCTK_GroupSizesI

[A276] Given a group index, returns the size array of that group

CCTK_GroupStorageDecrease

[A278] Decrease the active number of timelevels for a list of groups

CCTK_GroupStorageIncrease

[A280] Increase the active number of timelevels for a list of groups

CCTK_GroupTagsTable

[A282] Given a group name, return the table handle of the group’s tags table.

CCTK_GroupTagsTableI

[A285] Given a group index, return the table handle of the group’s tags table.

CCTK_GroupTypeFromVarI

[A288] Provides a group’s group type index given a variable index

CCTK_GroupTypeI

[A292] Provides a group’s group type index given a group index

CCTK_GroupubndGI

[A294] Given a group index, return an array of the upper bounds of the group in each dimension

CCTK_GroupubndGN

[A294] Given a group name, return an array of the upper bounds of the group in each dimension

CCTK_GroupubndVI

[A297] Given a variable index, return an array of the upper bounds of the variable in each dimension

CCTK_GroupubndVN

[A297] Given a variable name, return an array of the upper bounds of the variable in each dimension

CCTK_ImpFromVarI

[A300] Given a variable index, returns the implementation name for a public or protected variable, the thorn name otherwise.

CCTK_ImplementationRequires

[A302] Return the ancestors for an implementation

CCTK_ImplementationThorn

[A304] Returns the name of one thorn providing an implementation

CCTK_ImpThornList

[A306] Return the thorns for an implementation

CCTK_INFO

[A308] Macro to print a single string as an information message to screen

CCTK_Info

[A313] Function to print a single string as an information message to screen

CCTK_InfoCallbackRegister

[A317] Register one or more routines for dealing with information messages in addition to printing them to screen

CCTK_InterpGridArrays

[A321] Performs an interpolation on a list of CCTK grid variables, using a chosen external local interpolation operator

CCTK_InterpHandle

[A329] Returns the handle for a given interpolation operator

CCTK_InterpLocalUniform

[A333] Interpolate a list of processor-local arrays which define a uniformly-spaced data grid

CCTK_InterpRegisterOpLocalUniform

[A340] Registers a routine as a CCTK_InterpLocalUniform interpolation operator

CCTK_IsFunctionAliased

[A343] Reports whether an aliased function has been provided

CCTK_IsImplementationActive

[A346] Reports whether an implementation was activated in a parameter file

CCTK_IsImplementationCompiled

[A348] Reports whether an implementation was compiled into a configuration

CCTK_IsThornActive

[A350] Reports whether a thorn was activated in a parameter file

CCTK_IsThornCompiled

[A353] Reports whether a thorn was compiled into a configuration

CCTK_LocalArrayReduceOperator

[A355] Returns the name of a registered reduction operator

CCTK_LocalArrayReduceOperatorImplementation

[A357] Provide the implementation which provides an local array reduction operator

CCTK_LocalArrayReductionHandle

[A359] Returns the handle of a given local array reduction operator

CCTK_MaxActiveTimeLevels

[A361] Returns the maximum number of timeleves that were ever active from a group name

CCTK_MaxActiveTimeLevelsGI

[A361] Returns the maximum number of timeleves that were ever active from a group index

CCTK_MaxActiveTimeLevelsGN

[A361] Returns the maximum number of timeleves that were ever active from a group name

CCTK_MaxActiveTimeLevelsVI

[A361] Returns the maximum number of timeleves that were ever active from a variable index

CCTK_MaxActiveTimeLevelsVN

[A361] Returns the maximum number of timeleves that were ever active from a variable name

CCTK_MaxDim

[A365] Get the maximum dimension of any grid variable

CCTK_MaxGFDim

[A369] Get the maximum dimension of all grid functions

CCTK_MaxTimeLevels

CCTK_MyProc

[A373] Get the local processor number

CCTK_nProcs

[A374] Get the total number of processors used

CCTK_NullPointer

[A376] Returns a C-style NULL pointer value

CCTK_NumCompiledImplementations

[A378] Return the number of implementations compiled in

CCTK_NumCompiledThorns

[A380] Return the number of thorns compiled in

CCTK_NumGridArrayReductionOperators

[A382] The number of grid array reduction operators registered

CCTK_NumGroups

[A384] Get the number of groups of variables compiled in the code

CCTK_NumIOMethods

[A388] Returns the total number of I/O methods registered with the flesh

CCTK_NumLocalArrayReduceOperators

[A390] The number of local reduction operators registered

CCTK_NumReductionArraysGloballyOperators

[A392] The number of global array reduction operators registered

CCTK_NumTimerClocks

[A394] Returns the number of clocks in a cTimerData structure.

CCTK_NumVars

[A395] Get the number of grid variables compiled in the code

CCTK_NumVarsInGroup

[A399] Provides the number of variables in a group from the group name

CCTK_NumVarsInGroupI

[A403] Provides the number of variables in a group from the group index

CCTK_OutputGH

[A407] Conditional output of all variables on a GH by all I/O methods

CCTK_OutputVar

[A409] Output of a single variable by all I/O methods

CCTK_OutputVarAs

[A412] Output of a single variable as an alias by all I/O methods

CCTK_OutputVarAsByMethod

[A416] Output of a single variable as an alias by a single I/O method

CCTK_OutputVarByMethod

[A419] Output of a single variable by a single I/O method

CCTK_ParallelInit

[A422] Initializes the parallel subsystem

CCTK_ParameterData

[A423] Get parameter properties for given parameter/thorn pair

CCTK_ParameterGet

[A428] Get the data pointer to and type of a parameter’s value

CCTK_ParameterFilename

[A425] Returns the parameter filename

CCTK_ParameterLevel

[A430] Return the parameter checking level

CCTK_ParameterQueryTimesSet

[A431] Return number of times a parameter has been set

CCTK_ParameterSet

[A433] Sets the value of a parameter

CCTK_ParameterSetNotifyRegister

[A437] Registers a parameter set operation notify callback

CCTK_ParameterSetNotifyUnregister

[A441] Unregisters a parameter set operation notify callback

CCTK_ParameterValString

[A445] Get the string representation of a parameter’s value

CCTK_ParameterWalk

[A448] Walk through the list of parameters

CCTK_PARAMWARN

[A450] Prints a warning from parameter checking, and possibly stops the code

CCTK_PointerTo

[A455] Returns a pointer to a Fortran variable.

CCTK_PrintGroup

[A457] Prints a group name from its index

CCTK_PrintString

[A461] Prints a Cactus string to screen (from Fortran)

CCTK_PrintVar

[A465] Prints a variable name from its index

CCTK_QueryGroupStorage

[A469] Queries storage for a group given by its group name

CCTK_QueryGroupStorageB

[A471] Queries storage for a group given by its group name or index

CCTK_QueryGroupStorageI

[A474] Queries storage for a group given by its group index

CCTK_ReduceArraysGlobally

[A476] Reduces a list of local arrays globally

CCTK_ReduceGridArrays

[A483] Reduces a list of local arrays (new grid array reduction API)

CCTK_ReduceLocalArrays

[A489] Reduces a list of local arrays (new local array reduction API) Returns the address of a variable passed in by reference from a Fortran routine

CCTK_ReductionHandle

[A497] Get the handle for a registered reduction operator

CCTK_RegexMatch

[A501] Perform a regular expression match of string against pattern

CCTK_RegisterBanner

[A503] Register a banner for a thorn

CCTK_RegisterGHExtension

[A507] Register the name of an extension to the Cactus GH

CCTK_RegisterGHExtensionInitGH

[A508] Register a routine for providing initialisation for an extension to the Cactus GH

CCTK_RegisterGHExtensionScheduleTraverseGH

[A509] Register a GH extension schedule traversal routine

CCTK_RegisterGridArrayReductionOperator

[A511] Registers a function as a grid array reduction operator of a certain name

CCTK_RegisterGHExtensionSetupGH

[A510] Register a routine for setting up an extension to the Cactus GH

CCTK_RegisterIOMethod

[A513] Registers a new I/O method

CCTK_RegisterIOMethodOutputGH

[A515] Registers an I/O method’s routine for conditional output

CCTK_RegisterIOMethodOutputVarAs

[A516] Registers an I/O method’s routine for unconditional output

CCTK_RegisterIOMethodTimeToOutput

[A517] Register a routine for deciding if it is time to output for an IO method

CCTK_RegisterIOMethodTriggerOutput

[A518] Register a routine for dealing with trigger output for an IO method

CCTK_RegisterLocalArrayReductionOperator

[A519] Registers a function as a reduction operator of a certain name

CCTK_RegisterReduceArraysGloballyOperator

[A521] Register a function as providing a global array reduction operation

CCTK_RegisterReductionOperator

[A523] Register a function as providing a reduction operation

CCTK_RunTime

[A524] Return the number of seconds since the run started

CCTK_SchedulePrintTimes

[A525] Output the timing results for a certain schedule item to stdout

CCTK_SchedulePrintTimesToFile

[A527] Output the timing results for a certain schedule item to a file

CCTK_ScheduleQueryCurrentFunction

[A529] Return the cFunctionData of the function currently executing via CCTK_CallFunction

CCTK_ScheduleTraverse

[A531] Traverses a schedule point, and its entry and exit points if necessary

CCTK_SetupGH

[A534] Sets up a CCTK grid hierarchy

CCTK_SyncGroup

[A535] Synchronize the ghost zones for a group of variables (identified by the group name)

CCTK_SyncGroupI

[A539] Synchronize the ghost zones for a group of variables (identified by the group index)

CCTK_SyncGroupsI

[A544] Synchronize the ghost zones for a list of groups of variables (identified by their group indices)

CCTK_TerminateNext

[A549] Causes a Cactus simulation to terminate after the next iteration

CCTK_TerminationReached

[A551] Returns true if CCTK_TerminateNext has been called.

CCTK_ThornImplementation

[A554] Returns the implementation provided by the thorn

CCTK_Timer

[A557] Fills a timer cTimerData structure with current values of all clocks of a timer with a given name.

CCTK_TimerCreate

[A558] Create a timer with a given name, returns a timer index.

CCTK_TimerCreateData

[A559] Allocates a timer cTimerData structure.

CCTK_TimerCreateI

[A560] Create an unnamed timer, returns a timer index.

CCTK_TimerDestroy

[A561] Reclaims resources for a timer with a given name.

CCTK_TimerDestroyData

[A562] Reclaims resources of a timer cTimerData structure.

CCTK_TimerDestroyI

[A563] Reclaims resources for a timer with a given index.

CCTK_TimerI

[A564] Fills a timer cTimerData structure with current values of all clocks of a timer with a given index.

CCTK_TimerReset

[A565] Initialises the timer with a given name.

CCTK_TimerResetI

[A566] Initialises the timer with a given index.

CCTK_TimerStart

[A567] Initialises the timer with a given name.

CCTK_TimerStartI

[A568] Initialises the timer with a given index.

CCTK_TimerStop

[A569] Gets current values for all clocks of the timer with a given name.

CCTK_TimerStopI

[A570] Gets current values for all clocks of the timer with a given index.

CCTK_TraverseString

[A575] Traverse through all variables and/or groups whose names appear in the given string.

CCTK_VarDataPtr

[A577] Returns the data pointer for a grid variable

CCTK_VarDataPtrB

[A581] Returns the data pointer for a grid variable from the variable index or name

CCTK_VarDataPtrI

[A583] Returns the data pointer for a grid variable from the variable index

CCTK_VarIndex

[A587] Get the index for a variable

CCTK_VarName

[A591] Given a variable index, returns the variable name

CCTK_VarTypeI

[A594] Provides variable type index from the variable index

CCTK_VarTypeSize

[A598] Provides variable type size in bytes from the variable type index

CCTK_VECTGFINDEX1D

[A193] Given a set of vector and multidimensional indices compute the 1-dimensional index into a vector grid function.

CCTK_VECTGFINDEX1D

[A195] Given a set of vector and multidimensional indices compute the 2-dimensional index into a vector grid function.

CCTK_VECTGFINDEX3D

[A197] Given a set of vector and multidimensional indices compute the 3-dimensional index into a vector grid function.

CCTK_VECTGFINDEX4D

[A199] Given a set of vector and multidimensional indices compute the 4-dimensional index into a vector grid function.

CCTK_VERROR

[A610] Macro to print a formatted string with a variable argument list as error message to standard error and stops the code

CCTK_VError

[A613] Prints a formatted string with a variable argument list as error message to standard error and stops the code

CCTK_VINFO

[A616] Macro to print a formatted string with a variable argument list as an information message to screen

CCTK_VInfo

[A619] Prints a formatted string with a variable argument list as an information message to screen

CCTK_VPARAMWARN

[A624] Prints a formatted string with a variable argument list as a warning from parameter checking, and possibly stops the code

CCTK_VParamWarn

[A622] Prints a formatted string with a variable argument list as a warning from parameter checking, and possibly stops the code

CCTK_VWARN

[A626] Macro to print a formatted string with a variable argument list as a warning message to standard error and possibly stops the code

CCTK_VWarn

[A630] Prints a formatted string with a variable argument list as a warning message to standard error and possibly stops the code

CCTK_WARN

[A634] Macro to print a single string as a warning message to standard error and possibly stop the code

CCTK_Warn

[A639] Function to print a single string as a warning message to standard error and possibly stop the code

CCTK_WarnCallbackRegister

[A642] Register one or more routines for dealing with warning messages in addition to printing them to standard error

## Chapter A2Full Description of Functions

### CCTK_Abort

Abnormal Cactus termination.

Synopsis

C

#include "cctk.h"

int dummy = CCTK_Abort(const cGH *cctkGH, int exitcode);


Fortran

#include "cctk.h"

subroutine CCTK_Abort (dummy, cctkGH, exitcode)
integer      dummy
CCTK_POINTER cctkGH
integer      exitcode
end subroutine CCTK_Abort


Result

The function never returns, and hence never produces a result.

Parameters

GH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy.
exitcode Exit code that is passed to the operating system

Discussion

This routine causes an immediate, abnormal Cactus termination. It never returns to the caller.

CCTK_Exit [A166] Exit the code cleanly
CCTK_ERROR [A158] Macro to print a single string as error message and stop the code
CCTK_VError [A613] Prints a formatted string with a variable argument list as error message to standard error and stops the code
CCTK_VWarn [A630] Prints a formatted string with a variable argument list as a warning message to standard error and possibly stops the code
CCTK_WARN [A634] Macro to print a single string as a warning message and possibly stop the code

Errors

The function never returns, and hence never reports an error.

Examples

C

#include "cctk.h"
CCTK_Abort (cctkGH);


Fortran

#include "cctk.h"
integer dummy
call CCTK_Abort (dummy, cctkGH)


### CCTK_ActivatingThorn

Finds the thorn which activated a particular implementation.

Synopsis

C

#include "cctk.h"

const char *thorn = CCTK_ActivatingThorn(const char *name);


Result

thorn Name of activating thorn, or NULL if inactive

Parameters

name Implementation name

CCTK_CompiledImplementation [A79] Return the name of the compiled implementation with given index
CCTK_CompiledThorn [A81] Return the name of the compiled thorn with given index
CCTK_ImplementationRequires [A302] Return the ancestors for an implementation
CCTK_ImplementationThorn [A304] Returns the name of one thorn providing an implementation.
CCTK_ImpThornList [A306] Return the thorns for an implementation
CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file
CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration
CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file
CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration
CCTK_NumCompiledImplementations [A378] Return the number of implementations compiled in
CCTK_NumCompiledThorns [A380] Return the number of thorns compiled in
CCTK_ThornImplementation [A554] Returns the implementation provided by the thorn

Errors

NULL The implementation is inactive, or an error occurred.

### CCTK_ActiveTimeLevels

Returns the number of active time levels for a group.

Synopsis

C

#include "cctk.h"

int timelevels = CCTK_ActiveTimeLevels(const cGH *cctkGH,
const char *groupname);

int timelevels = CCTK_ActiveTimeLevelsGI(const cGH *cctkGH,
int groupindex);

int timelevels = CCTK_ActiveTimeLevelsGN(const cGH *cctkGH,
const char *groupname);

int timelevels = CCTK_ActiveTimeLevelsVI(const cGH *cctkGH,
int varindex);

int timelevels = CCTK_ActiveTimeLevelsVN(const cGH *cctkGH,
const char *varname);


Fortran

#include "cctk.h"

subroutine CCTK_ActiveTimeLevels(timelevels, cctkGH, groupname)
integer       timelevels
CCTK_POINTER  cctkGH
character*(*) groupname
end subroutine CCTK_ActiveTimeLevels

subroutine CCTK_ActiveTimeLevelsGI(timelevels, cctkGH, groupindex)
integer       timelevels
CCTK_POINTER  cctkGH
integer       groupindex
end subroutine CCTK_ActiveTimeLevelsGI

subroutine CCTK_ActiveTimeLevelsGN(timelevels, cctkGH, groupname)
integer       timelevels
CCTK_POINTER  cctkGH
character*(*) groupname
end subroutine CCTK_ActiveTimeLevelsGN

subroutine CCTK_ActiveTimeLevelsVI(timelevels, cctkGH, varindex)
integer       timelevels
CCTK_POINTER  cctkGH
integer       varindex
end subroutine CCTK_ActiveTimeLevelsVI

subroutine CCTK_ActiveTimeLevelsVN(timelevels, cctkGH, varname)
integer       timelevels
CCTK_POINTER  cctkGH
character*(*) varname
end subroutine CCTK_ActiveTimeLevelsVN


Result

timelevels The currently active number of timelevels for the group.

Parameters

GH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy.
groupname Name of the group.
groupindex Index of the group.
varname Name of a variable in the group.
varindex Index of a variable in the group.

Discussion

This function returns the number of timelevels for which storage has been activated, which is always equal to or less than the maximum number of timelevels which may have storage provided by CCTK_MaxActiveTimeLevels.

CCTK_MaxActiveTimeLevels [A361] Returns the maximum number of timeleves that were ever active from a group name
CCTK_DeclaredTimeLevels [A121] Return the maximum number of active timelevels.
CCTK_GroupStorageDecrease [A278] Base function, overloaded by the driver, which decreases the number of active timelevels, and also returns the number of active timelevels.
CCTK_GroupStorageIncrease [A280] Base function, overloaded by the driver, which increases the number of active timelevels, and also returns the number of active timelevels.

Errors

timelevels $<$ 0 Illegal arguments given.

### CCTK_ArrayGroupSize

Returns a pointer to the processor-local size for variables in a group, specified by its name, in a given dimension.

Synopsis

C

#include "cctk.h"
int *size = CCTK_ArrayGroupSize(const cGH *cctkGH,
int dir,
const char *groupname);


Result

NULL A NULL pointer is returned if the group index or the dimension given are invalid.

Parameters

GH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy.
dir ($\ge$ 0) Which dimension of array to query.
groupname Name of the group.

Discussion

For a CCTK_ARRAY or CCTK_GF group, this routine returns a pointer to the processor-local size for variables in that group in a given direction. The direction is counted in C order (zero being the lowest dimension).

This function returns a pointer to the result for technical reasons; so that it will efficiently interface with Fortran. This may change in the future. Consider using CCTK_GroupgshGN instead.

CCTK_GroupgshGN [A230] Returns an array with the array size in all dimensions.
... There are many related functions which grab information from the GH, but many are not yet documented.

### CCTK_ArrayGroupSizeI

Returns a pointer to the processor-local size for variables in a group, specified by its index, in a given dimension.

Synopsis

C

#include "cctk.h"
int *size = CCTK_ArrayGroupSizeI(const cGH *cctkGH,
int dir,
int groupi);


Result

NULL A NULL pointer is returned if the group index or the dimension given are invalid.

Parameters

GH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy.
dir ($\ge$ 0) Which dimension of array to query.
groupi The group index.

Discussion

For a CCTK_ARRAY or CCTK_GF group, this routine returns a pointer to the processor-local size for variables in that group in a given direction. The direction is counted in C order (zero being the lowest dimension).

This function returns a pointer to the result for technical reasons; so that it will efficiently interface with Fortran. This may change in the future. Consider using CCTK_GroupgshGI instead.

CCTK_GroupgshGI [A230] Returns an array with the array size in all dimensions.
... There are many related functions which grab information from the GH, but many are not yet documented.

### CCTK_Barrier

Synchronizes all processors at a given execution point This routine synchronizes all processors in a parallel job at a given point of execution. No processor will continue execution until all other processors have called CCTK_Barrier. Note that this is a collective operation – it must be called by all processors otherwise the code will hang.

Synopsis

C

int istat = CCTK_Barrier(const cGH *cctkGH)


Fortran

subroutine CCTK_Barrier (istat, cctkGH)
integer               itat
CCTK_POINTER_TO_CONST cctkGH


### CCTK_ClockRegister

Registers a named timer clock with the Flesh.

Synopsis

C

int err = CCTK_ClockRegister(name, functions)


Parameters

const char * name The name the clock will be given

const cClockFuncs * functions The structure holding the function pointers that define the clock

Discussion

The cClockFuncs structure contains function pointers defined by the clock module to be registered.

Errors

A negative return value indicates an error.

### CCTK_Cmplx

Turns two real numbers into a complex number (deprecated)

Synopsis

C

CCTK_COMPLEX cmpno = CCTK_Cmplx( CCTK_REAL realpart, CCTK_REAL imagpart)


Parameters

cmpno The complex number
realpart The real part of the complex number
imagpart The imaginary part of the complex number

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

cmpno = CCTK_Cmplx(re,im);


### CCTK_CmplxAbs

Absolute value of a complex number (deprecated)

Synopsis

C

CCTK_COMPLEX absval = CCTK_CmplxAbs( CCTK_COMPLEX inval)


Parameters

absval The computed absolute value
realpart The complex number who absolute value is to be returned

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

absval = CCTK_CmplxAbs(inval);


Sum of two complex numbers (deprecated)

Synopsis

C

CCTK_COMPLEX addval = CCTK_CmplxAdd( CCTK_COMPLEX inval1, CCTK_COMPLEX inval2)


Parameters

inval1 The first complex number to be summed
inval2 The second complex number to be summed

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

addval = CCTK_CmplxAdd(inval1,inval2);


### CCTK_CmplxConjg

Complex conjugate of a complex number (deprecated)

Synopsis

C

CCTK_COMPLEX conjgval = CCTK_CmplxConjg( CCTK_COMPLEX inval)


Parameters

conjval The computed conjugate
inval The complex number to be conjugated

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

conjgval = CCTK_CmplxConjg(inval);


### CCTK_CmplxCos

Cosine of a complex number (deprecated)

Synopsis

C

CCTK_COMPLEX cosval = CCTK_CmplxCos( CCTK_COMPLEX inval)


Parameters

cosval The computed cosine
inval The complex number to be cosined

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

cosval = CCTK_CmplxCos(inval);


### CCTK_CmplxDiv

Division of two complex numbers (deprecated)

Synopsis

C

CCTK_COMPLEX divval = CCTK_CmplxDiv( CCTK_COMPLEX inval1, CCTK_COMPLEX inval2)


Parameters

divval The divided value
inval1 The enumerator
inval1 The denominator

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

divval = CCTK_CmplxDiv(inval1,inval2);


### CCTK_CmplxExp

Exponent of a complex number (deprecated)

Synopsis

C

CCTK_COMPLEX expval = CCTK_CmplxExp( CCTK_COMPLEX inval)


Parameters

expval The computed exponent
inval The complex number to be exponented

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

expval = CCTK_CmplxExp(inval);


### CCTK_CmplxImag

Imaginary part of a complex number (deprecated)

Synopsis

C

CCTK_REAL imval = CCTK_CmplxImag( CCTK_COMPLEX inval)


Parameters

imval The imaginary part
inval The complex number

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

The imaginary part of a complex number $z=a+bi$ is $b$.

Examples

C

imval = CCTK_CmplxImag(inval);


### CCTK_CmplxLog

Logarithm of a complex number (deprecated)

Synopsis

C

CCTK_COMPLEX logval = CCTK_CmplxLog( CCTK_COMPLEX inval)


Parameters

logval The computed logarithm
inval The complex number

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

logval = CCTK_CmplxLog(inval);


### CCTK_CmplxMul

Multiplication of two complex numbers (deprecated)

Synopsis

C

CCTK_COMPLEX mulval = CCTK_CmplxMul( CCTK_COMPLEX inval1, CCTK_COMPLEX inval2)


Parameters

mulval The product
inval1 First complex number to be multiplied
inval2 Second complex number to be multiplied

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

The product of two complex numbers ${z}_{1}={a}_{1}+{b}_{1}i$ and ${z}_{2}={a}_{2}+{b}_{2}i$ is $z=\left({a}_{1}{a}_{2}-{b}_{1}{b}_{2}\right)+\left({a}_{1}{b}_{2}+{a}_{2}{b}_{1}\right)i$.

Examples

C

mulval = CCTK_CmplxMul(inval1,inval2);


### CCTK_CmplxReal

Real part of a complex number (deprecated)

Synopsis

C

CCTK_REAL reval = CCTK_CmplxReal( CCTK_COMPLEX inval)


Parameters

reval The real part
inval The complex number

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

The real part of a complex number $z=a+bi$ is $a$.

Examples

C

reval = CCTK_CmplxReal(inval);


### CCTK_CmplxSin

Sine of a complex number (deprecated)

Synopsis

C

CCTK_COMPLEX sinval = CCTK_CmplxSin( CCTK_COMPLEX inval)


Parameters

sinval The computed sine
inval The complex number to be Sined

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

sinval = CCTK_CmplxSin(inval);


### CCTK_CmplxSqrt

Square root of a complex number (deprecated)

Synopsis

C

CCTK_COMPLEX sqrtval = CCTK_CmplxSqrt( CCTK_COMPLEX inval)


Parameters

expval The computed square root
inval The complex number to be square rooted

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

Examples

C

sqrtval = CCTK_CmplxSqrt(inval);


### CCTK_CmplxSub

Subtraction of two complex numbers (deprecated)

Synopsis

C

CCTK_COMPLEX subval = CCTK_CmplxSub( CCTK_COMPLEX inval1, CCTK_COMPLEX inval2)


Parameters

inval1 The complex number to be subtracted from
inval2 The complex number to subtract

Discussion

This function is deprecated in favor of the native complex number support in C99 and C++.

If ${z}_{1}={a}_{1}+{b}_{1}i$ and ${z}_{2}={a}_{2}+{b}_{2}i$ then

${z}_{1}-{z}_{2}=\left({a}_{1}-{a}_{2}\right)+\left({b}_{1}-{b}_{2}\right)i$

Examples

C

subval = CCTK_CmplxSub(inval1,inval2);


### CCTK_CommandLine

Gets the command line arguments.

Synopsis

C

#include "cctk.h"
int outargc = CCTK_CommandLine(char ***outargv)


Result

outargc The number of command line arguments.

Parameters

outargc Place to dump the command line arguments

CCTK_ParameterFilename [A425] Returns the parameter filename

### CCTK_CompileDate

Returns a formatted string containing the date stamp when Cactus was compiled

Synopsis

C

#include "cctk.h"

const char *compile_date = CCTK_CompileDate ();


Result

compile_date formatted string containing the date stamp

CCTK_CompileTime [A77] Returns a formatted string containing the time stamp when Cactus was compiled
CCTK_CompileDateTime [A76] Returns a formatted string containing the datetime stamp when Cactus was compiled

### CCTK_CompileDateTime

Returns a formatted string containing the datetime stamp when Cactus was compiled

Synopsis

C

#include "cctk.h"

const char *compile_datetime = CCTK_CompileDateTime ();


Result

compile_datetime formatted string containing the datetime stamp

Discussion

If possible, the formatted string returned contains the datetime in a machine-processable format as defined in ISO 8601 chapter 5.4.

CCTK_CompileDate [A75] Returns a formatted string containing the date stamp when Cactus was compiled
CCTK_CompileTime [A77] Returns a formatted string containing the time stamp when Cactus was compiled

### CCTK_CompileTime

Returns a formatted string containing the time stamp when Cactus was compiled

Synopsis

C

#include "cctk.h"

const char *compile_time = CCTK_CompileTime ();


Result

compile_time formatted string containing the time stamp

CCTK_CompileDate [A75] Returns a formatted string containing the date stamp when Cactus was compiled
CCTK_CompileDateTime [A76] Returns a formatted string containing the datetime stamp when Cactus was compiled

### CCTK_CompiledImplementation

Return the name of the compiled implementation with given index.

Synopsis

C

#include "cctk.h"

const char *imp = CCTK_CompiledImplementation(int index);


Result

imp Name of the implementation

Parameters

index Implementation index, with $0\le \text{index}<\text{numimpls}$, where numimpls is returned by CCTK_NumCompiledImplementations.

CCTK_ActivatingThorn [A32] Finds the thorn which activated a particular implementation
CCTK_CompiledThorn [A81] Return the name of the compiled thorn with given index
CCTK_ImplementationRequires [A302] Return the ancestors for an implementation
CCTK_ImplementationThorn [A304] Returns the name of one thorn providing an implementation.
CCTK_ImpThornList [A306] Return the thorns for an implementation
CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file
CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration
CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file
CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration
CCTK_NumCompiledImplementations [A378] Return the number of implementations compiled in
CCTK_NumCompiledThorns [A380] Return the number of thorns compiled in
CCTK_ThornImplementation [A554] Returns the implementation provided by the thorn

Errors

NULL Error.

### CCTK_CompiledThorn

Return the name of the compiled thorn with given index.

Synopsis

C

#include "cctk.h"

const char *thorn = CCTK_CompiledThorn(int index);


Result

thorn Name of the thorn

Parameters

index Thorn index, with $0\le \text{index}<\text{numthorns}$, where numthorns is returned by CCTK_NumCompiledThorns.

CCTK_ActivatingThorn [A32] Finds the thorn which activated a particular implementation
CCTK_CompiledImplementation [A79] Return the name of the compiled implementation with given index
CCTK_ImplementationRequires [A302] Return the ancestors for an implementation
CCTK_ImplementationThorn [A304] Returns the name of one thorn providing an implementation.
CCTK_ImpThornList [A306] Return the thorns for an implementation
CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file
CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration
CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file
CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration
CCTK_NumCompiledImplementations [A378] Return the number of implementations compiled in
CCTK_NumCompiledThorns [A380] Return the number of thorns compiled in
CCTK_ThornImplementation [A554] Returns the implementation provided by the thorn

Errors

NULL Error.

### CCTK_CoordDir

Give the direction for a given coordinate.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

int dir = CCTK_CoordDir( const char * coordname, const char * systemname)


Fortran

call CCTK_CoordDir(dir , coordname, systemname )

integer dir
character*(*) coordname
character*(*) systemname


Parameters

dir The direction of the coordinate
coordname The name assigned to this coordinate
systemname The name of the coordinate system

Discussion

The coordinate name is independent of the grid function name.

Examples

C

direction = CCTK_CoordDir("xdir","cart3d");


Fortran

call  CCTK_COORDDIR(direction,"radius","spher3d")


### CCTK_CoordIndex

Give the grid variable index for a given coordinate.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

int index = CCTK_CoordIndex( int direction, const char * coordname, const char * systemname)


Fortran

call CCTK_CoordIndex(index , direction, coordname, systemname )

integer index
integer direction
character*(*) coordname
character*(*) systemname


Parameters

index The coordinates associated grid variable index
direction The direction of the coordinate in this coordinate system
coordname The name assigned to this coordinate
systemname The coordinate system for this coordinate

Discussion

The coordinate name is independent of the grid variable name. To find the index, the coordinate system name must be given, and either the coordinate direction or the coordinate name. The coordinate name will be used if the coordinate direction is given as less than or equal to zero, otherwise the coordinate name will be used.

Examples

C

index = CCTK_CoordIndex(-1,"xdir","cart3d");


C

call  CCTK_COORDINDEX(index,one,"radius","spher2d")


### CCTK_CoordRange

Return the global upper and lower bounds for a given coordinate.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

int ierr = CCTK_CoordRange( const cGH * cctkGH, CCTK_REAL * lower, CCTK_REAL * upper, int direction, const char * coordname, const char * systemname)


Fortran

call CCTK_CoordRange(ierr , cctkGH, lower, upper, direction, coordname, systemname )

integer ierr
CCTK_POINTER cctkGH
CCTK_REAL lower
CCTK_REAL upper
integer direction
character*(*) coordname
character*(*) systemname


Parameters

ierr Error code
cctkGH pointer to CCTK grid hierarchy
lower Global lower bound of the coordinate (POINTER in C)
upper Global upper bound of the coordinate (POINTER in C)
direction Direction of coordinate in coordinate system
coordname Coordinate name
systemname Coordinate system name

Discussion

The coordinate name is independent of the grid function name. The coordinate range is registered by CCTK_CoordRegisterRange. To find the range, the coordinate system name must be given, and either the coordinate direction or the coordinate name. The coordinate direction will be used if is given as a positive value, otherwise the coordinate name will be used.

Examples

C

ierr = CCTK_CoordRange(cctkGH, &xmin, &xmax, -1, "xdir", "mysystem");


Fortran

call CCTK_COORDRANGE(ierr, cctkGH, Rmin, Rmax, -1, "radius", "sphersystem")


### CCTK_CoordRegisterData

Define a coordinate in a given coordinate system.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

int ierr = CCTK_CoordRegisterData( int direction, const char * gvname, const char * coordname, const char * systemname)


Fortran

call CCTK_CoordRegisterData(ierr , direction, gvname, coordname, systemname )

integer ierr
integer direction
character*(*) gvname
character*(*) coordname
character*(*) systemname


Parameters

ierr Error code
direction Direction of coordinate in coordinate system
gvname Name of grid variable associated with coordinate
coordname Name of this coordinate
systemname Name of this coordinate system

Discussion

There must already be a coordinate system registered, using CCTK_CoordRegisterSystem.

Examples

C

ierr = CCTK_CoordRegisterData(1,"coordthorn::myx","x2d","cart2d");


Fortran

two = 2
call CCTK_COORDREGISTERDATA(ierr,two,"coordthorn::mytheta","spher3d")


### CCTK_CoordRegisterRange

Assign the global maximum and minimum values of a coordinate on a given grid hierachy.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

int ierr = CCTK_CoordRegisterRange( const cGH * cctkGH, CCTK_REAL min, CCTK_REAL max, int direction, const char * coordname, const char * systemname)


Fortran

call CCTK_CoordRegisterRange(ierr , cctkGH, min, max, direction, coordname, systemname )

integer ierr
CCTK_POINTER cctkGH
CCTK_REAL min
CCTK_REAL max
integer direction
character*(*) coordname
character*(*) systemname


Parameters

ierr Error code
dimension Pointer to CCTK grid hierachy
min Global minimum of coordinate
max Global maximum of coordinate
direction Direction of coordinate in coordinate system
coordname Name of coordinate in coordinate system
systemname Name of this coordinate system

Discussion

There must already be a coordinate registered with the given name, with CCTK_CoordRegisterData. The coordinate range can be accessed by CCTK_CoordRange.

Examples

C

ierr = CCTK_CoordRegisterRange(cctkGH,-1.0,1.0,1,"x2d","cart2d");


Fortran

min = 0
max = 3.1415d0/2.0d0
two = 2
call CCTK_COORDREGISTERRANGE(ierr,min,max,two,"coordthorn::mytheta","spher3d")


### CCTK_CoordRegisterSystem

Assigns a coordinate system with a chosen name and dimension.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

int ierr = CCTK_CoordRegisterSystem( int dimension, const char * systemname)


Fortran

call CCTK_CoordRegisterSystem(ierr , dimension, systemname )

integer ierr
integer dimension
character*(*) systemname


Parameters

ierr Error code
dimension Dimension of coordinate system
systemname Unique name assigned to coordinate system

Examples

C

ierr = CCTK_CoordRegisterSystem(3,"cart3d");


Fortran

three = 3
call CCTK_COORDREGISTERSYSTEM(ierr,three,"sphersystem")


### CCTK_CoordSystemDim

Give the dimension for a given coordinate system.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

int dim = CCTK_CoordSystemDim( const char * systemname)


Fortran

call CCTK_CoordSystemDim(dim , systemname )

integer dim
character*(*) systemname


Parameters

dim The dimension of the coordinate system
systemname The name of the coordinate system

Examples

C

dim = CCTK_CoordSystemDim("cart3d");


Fortran

call  CCTK_COORDSYSTEMDIM(dim,"spher3d")


### CCTK_CoordSystemHandle

Returns the handle associated with a registered coordinate system.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

int handle = CCTK_CoordSystemHandle( const char * systemname)


Fortran

call CCTK_CoordSystemHandle(handle , systemname )

integer handle
character*(*) systemname


Parameters

handle The coordinate system handle
systemname Name of the coordinate system

Examples

C

handle =  CCTK_CoordSystemHandle("my coordinate system");


Fortran

call CCTK_CoordSystemHandle(handle,"my coordinate system")


Errors

negative A negative return code indicates an invalid coordinate system name.

### CCTK_CoordSystemName

Returns the name of a registered coordinate system.

All the CCTK_Coord* APIs are deprecated, and will probably be phased out fairly soon. New code should use the APIs provided by the CoordBase thorn instead (this lives in the CactusBase arrangement).

Synopsis

C

const char * systemname = CCTK_CoordSystemName(  int handle)


Parameters

handle The coordinate system handle
systemname The coordinate system name

Discussion

No Fortran routine exists at the moment.

Examples

C

systemname = CCTK_CoordSystemName(handle);
handle =  CCTK_CoordSystemHandle(systemname);


Errors

NULL A NULL pointer is returned if an invalid handle was given.

### CCTK_CreateDirectory

Create a directory with required permissions

Synopsis

C

int ierr = CCTK_CreateDirectory( int mode, const char * pathname)


Fortran

call CCTK_CreateDirectory(ierr , mode, pathname )

integer ierr
integer mode
character*(*) pathname


Parameters

ierr Error code
mode Permission mode for new directory as an octal number
pathname Directory to create

Discussion

To create a directory readable by everyone, but writeable only by the user running the code, the permission mode would be 0755. Alternatively, a permission mode of 0777 gives everyone unlimited access; the user’s umask setting should cut this down to whatever the user’s normal default permissions are anyway.

Note that (partly for historical reasons and partly for Fortran 77 compatability) the order of the arguments is the opposite of that of the usual Unix mkdir(2) system call.

Examples

C

ierr = CCTK_CreateDirectory(0755, "Results/New");


Fortran

call CCTK_CREATEDIRECTORY(ierr,0755, "Results/New")


Errors

0 Directory successfully created
-1 Memory allocation failed
-2 Failed to create directory
-3 Some component of pathname already exists but is not a directory

### CCTK_DeclaredTimeLevels

Gives the number of timelevels for a group

Synopsis

C

int numlevels = CCTK_DeclaredTimeLevels( const char * name)


Fortran

call CCTK_DeclaredTimeLevels(numlevels , name )

integer numlevels
character*(*) name


Parameters

name The full group name
numlevels The number of timelevels

Discussion

The group name should be in the form <implementation>::<group>

Examples

C

numlevels = CCTK_DeclaredTimeLevels("evolve::phivars");


Fortran

call CCTK_DECLAREDTIMELEVELS(numlevels,"evolve::phivars")


### CCTK_DeclaredTimeLevelsGI

Gives the number of timelevels for a group

Synopsis

C

int numlevels = CCTK_DeclaredTimeLevelsGI( int index)


Fortran

call CCTK_DeclaredTimeLevelsGI(numlevels , index )

integer numlevels
integer index


Parameters

numlevels The number of timelevels
index The group index

Examples

C

index = CCTK_GroupIndex("evolve::phivars")
numlevels = CCTK_DeclaredTimeLevelsGI(index);


Fortran

call CCTK_DECLAREDTIMELEVELSGI(numlevels,3)}


### CCTK_DeclaredTimeLevelsGN

Gives the number of timelevels for a group

Synopsis

C

int retval = CCTK_DeclaredTimeLevelsGN(const char *group);


Result

The maximum number of timelevels this group has, or -1 if the group name is incorrect.

Parameters

group The variable group’s name

Discussion

This function and its relatives return the maximum number of timelevels that the given variable group can have active. This function does not tell you anything about how many time levels are active at the time.

### CCTK_DeclaredTimeLevelsVI

Gives the number of timelevels for a variable

Synopsis

C

int numlevels = CCTK_DeclaredTimeLevelsVI( int index)


Fortran

call CCTK_DeclaredTimeLevelsVI(numlevels , index )

integer numlevels
integer index


Parameters

numlevels The number of timelevels
index The variable index

Examples

C

index = CCTK_VarIndex("evolve::phi")
numlevels = CCTK_DeclaredTimeLevelsVI(index);


Fortran

call CCTK_DECLAREDTIMELEVELSVI(numlevels,3)


### CCTK_DeclaredTimeLevelsVN

Gives the number of timelevels for a variable

Synopsis

C

int numlevels = CCTK_DeclaredTimeLevelsVN( const char * name)


Fortran

call CCTK_DeclaredTimeLevelsVN(numlevels , name )

integer numlevels
character*(*) name


Parameters

name The full variable name
numlevels The number of timelevels

Discussion

The variable name should be in the form <implementation>::<variable>

Examples

C

numlevels = CCTK_DeclaredTimeLevelsVN("evolve::phi")


Fortran

call CCTK_DECLAREDTIMELEVELSVN(numlevels,"evolve::phi")


### CCTK_DecomposeName

Given the full name of a variable/group, separates the name returning both the implementation and the variable/group

Synopsis

C

int istat = CCTK_DecomposeName( const char * fullname, char ** imp, char ** name)


Parameters

istat Status flag returned by routine
fullname The full name of the group/variable
imp The implementation name
name The group/variable name

Discussion

The implementation name and the group/variable name must be explicitly freed after they have been used.

No Fortran routine exists at the moment.

Examples

C

istat = CCTK_DecomposeName("evolve::scalars",imp,name)


### CCTK_DisableGroupComm

Turn communications off for a group of grid variables

Synopsis

C

int istat = CCTK_DisableGroupComm( cGH * cctkGH, const char * group)


Parameters

cctkGH pointer to CCTK grid hierarchy

Discussion

Turning off communications means that ghost zones will not be communicated during a call to CCTK_SyncGroup. By default communications are all off.

### CCTK_DisableGroupCommI

Turn communications off for a group of grid variables.

Synopsis

C

int istat = CCTK_DisableGroupCommI(cGH * cctkGH, int group);


Result

0 The Group has been disabled.

Parameters

cctkGH pointer to CCTK grid hierarchy
group number of group of grid variables to turn off

Discussion

Turning off communications means that ghost zones will not be communicated during a call to CCTK_SyncGroup. By default communications are all off.

CCTK_DisableGroupComm [A140] Turn communications off for a group of grid variables.
CCTK_EnableGroupCommI [A147] Turn communications on for a group of grid variables.
CCTK_EnableGroupComm [A145] Turn communications on for a group of grid variables.

### CCTK_DisableGroupStorage

Free the storage associated with a group of grid variables

Synopsis

C

int istat = CCTK_DisableGroupStorage( cGH * cctkGH, const char * group)


Parameters

cctkGH pointer to CCTK grid hierarchy

### CCTK_DisableGroupStorageI

Deallocates memory for a group based upon its index

Synopsis

C

int  CCTK_DisableGroupStorageI(const cGH *GH, int group);


Result

0 The group previously had storage
1 The group did not have storage to disable storage
-1 The decrease storage routine was not overloaded

Parameters

GH pointer to grid hierarchy
group index of the group to deallocate storage for

Discussion

The disable group storage routine should deallocate memory for a group and return the previous status of that memory. This default function checks for the presence of the newer GroupStorageDecrease function, and if that is not available it flags an error. If it is available it makes a call to it, passing -1 as the timelevel argument, which is supposed to mean disable all timelevels, i.e. preserving this obsolete behaviour.

### CCTK_EnableGroupComm

Turn communications on for a group of grid variables

Synopsis

C

int istat = CCTK_EnableGroupComm( cGH * cctkGH, const char * group)


Parameters

cctkGH pointer to CCTK grid hierarchy

Discussion

Grid variables with communication enabled will have their ghost zones communicated during a call to CCTK_SyncGroup. In general, this function does not need to be used, since communication is automatically enabled for grid variables who have assigned storage via the schedule.ccl file.

### CCTK_EnableGroupCommI

Turn communications on for a group of grid variables.

Synopsis

C

int istat = CCTK_EnableGroupCommI(cGH * cctkGH, int group);


Result

0 The Group has been enabled.

Parameters

cctkGH pointer to CCTK grid hierarchy
group number of the group of grid variables to turn on

Discussion

Grid variables with communication enabled will have their ghost zones communicated during a call to CCTK_SyncGroup. In general, this function does not need to be used, since communication is automatically enabled for grid variables who have assigned storage via the schedule.ccl file.

CCTK_DisableGroupComm [A140] Turn communications off for a group of grid variables.
CCTK_DisableGroupCommI [A141] Turn communications off for a group of grid variables.
CCTK_EnableGroupComm [A147] Turn communications on for a group of grid variables.

### CCTK_EnableGroupStorage

Assign the storage for a group of grid variables

Synopsis

C

int istat = CCTK_EnableGroupStorage(cGH * cctkGH, const char * group);


Result

0 The Storage has been enabled.

Parameters

cctkGH pointer to CCTK grid hierarchy
group name of the group to allocate storage for

Discussion

In general this function does not need to be used, since storage assignment is best handled by the Cactus scheduler via a thorn’s schedule.ccl file.

### CCTK_EnableGroupStorageI

Assign the storage for a group of grid variables

Synopsis

C

int istat = CCTK_EnableGroupStorageI(cGH * cctkGH, int group);


Result

0 The Storage has been enabled.

Parameters

cctkGH pointer to CCTK grid hierarchy
group Index of the group to allocate storage for

Discussion

In general this function does not need to be used, since storage assignment is best handled by the Cactus scheduler via a thorn’s schedule.ccl file.

### CCTK_Equals

Checks a STRING or KEYWORD parameter for equality with a given string

Synopsis

C

#include "cctk.h"
int status = CCTK_Equals(const char* parameter, const char* value)


Fortran

integer status
CCTK_POINTER  parameter
character*(*) value
status = CCTK_Equals(parameter, value)


Result

1 if the parameter is (case-independently) equal to the specified value
0 if the parameter is (case-independently) not equal to the specified value

Parameters

parameter The string or keyword parameter to compare; Cactus represents this as a CCTK_POINTER pointing to the string value.
value The value against which to compare the string or keyword parameter. This is typically a string literal (see the examples below).

Discussion

This function compares a Cactus parameter of type STRING or KEYWORD against a given string value. The comparison is performed case-independently, returning a 1 if the strings are equal, and zero if they differ.

Note that in Fortran code, STRING or KEYWORD parameters are passed as C pointers, and can not be treated as normal Fortran strings. Thus CCTK_Equals should be used to check the value of such a parameter. See the examples below for typical usage.

Util_StrCmpi [B18] compare two C-style strings case-independently

Errors

null pointer If either argument is passed as a null pointer, CCTK_Equals() aborts the Cactus run with an error message. Otherwise, there are no error returns from this function.

Examples

C

#include "cctk.h"
#include "cctk_Arguments.h"
#include "cctk_Parameters.h"

/*
* assume this thorn has a string or keyword parameter  my_parameter
*/
void MyThorn_some_function(CCTK_ARGUMENTS)
{
DECLARE_CCTK_ARGUMENTS;
DECLARE_CCTK_PARAMETERS;

if (CCTK_Equals(my_parameter, "option A")) {
CCTK_VInfo(CCTK_THORNSTRING, "using option A");
}
}


Fortran

#include "cctk.h"
#include "cctk_Arguments.h"
#include "cctk_Functions.h"
#include "cctk_Parameters.h"

!
! assume this thorn has a string or keyword parameter  my_parameter
!
subroutine MyThorn_some_routine(CCTK_ARGUMENTS)
implicit none
DECLARE_CCTK_ARGUMENTS
DECLARE_CCTK_FUNCTIONS
DECLARE_CCTK_PARAMETERS

if (CCTK_Equals(my_parameter, "option A") /= 0) then
call CCTK_INFO("using option A")
end if
end subroutine MyThorn_some_routine


### CCTK_ERROR

Macro to print a single string as error message and stop the code

Synopsis

C

#include <cctk.h>

CCTK_ERROR(const char *message);


Fortran

#include "cctk.h"

call CCTK_ERROR(message)
character*(*) message


Parameters

message The error message to print

Discussion

This macro can be used by thorns to print a single string as error message to stderr.

CCTK_ERROR(message) expands to a call to a CCTK_Error() which is equivalent to CCTK_VError(), but without the variable-number-of-arguments feature (so it can be used from Fortran).1 The macro automatically includes details about the origin of the warning (the thorn name, the source code file name and the line number where the macro occurs).

To include variables in the error message from C, you can use the routine CCTK_VError which accepts a variable argument list. To include variables from Fortran, a string must be constructed and passed in a CCTK_ERROR macro.

CCTK_Abort [A27] Abort the code
CCTK_Exit [A166] Exit the code cleanly
CCTK_VERROR [A610] macro to print an error message with a variable argument list
CCTK_VWARN [A626] macro to print a formatted string with a variable argument list as a warning message to standard error and possibly stops the code
CCTK_WARN [A634] Macro to print a single string as a warning message and possibly stop the code

Examples

C

#include <cctk.h>

CCTK_ERROR("Divide by 0");


Fortran

#include "cctk.h"

integer       myint
CCTK_REAL     myreal
character*200 message

write(message, ’(A32, G12.7, A5, I8)’)
&     ’Your error message, including ’, myreal, ’ and ’, myint
call CCTK_ERROR(message)


### CCTK_Error

Function to print a single string as error message and stop the code

Synopsis

C

#include <cctk.h>

void CCTK_Error(int line_number, const char* file_name,
const char* thorn_name,const char* message)


Fortran

#include "cctk.h"

call CCTK_Error(line_number, file_name, thorn_name, message)
integer line_number
character*(*) file_name, thorn_name, message


Parameters

line_number The line number in the originating source file where the CCTK_VError call occured. You can use the standardized __LINE__ preprocessor macro here.
file_name The file name of the originating source file where the CCTK_VError call occured. You can use the standardized __FILE__ preprocessor macro here.
thorn_name The thorn name of the originating source file where the CCTK_VError call occured. You can use the CCTK_THORNSTRING macro here (defined in cctk.h).
message The error message to print

Discussion

The macro CCTK_ERROR automatically includes the line number, file name and the name of the originating thorn in the info message. It is recommended that the macro CCTK_ERROR is used to print a message rather than calling CCTK_Error directly.

CCTK_Abort [A27] Abort the code
CCTK_Exit [A166] Exit the code cleanly
CCTK_VERROR [A610] macro to print an error message with a variable argument list
CCTK_VWARN [A626] macro to print a formatted string with a variable argument list as a warning message to standard error and possibly stops the code
CCTK_WARN [A634] Macro to print a single string as a warning message and possibly stop the code

### CCTK_Exit

Exit the code cleanly

Synopsis

C

int istat = CCTK_Exit( cGH * cctkGH, int value)


Fortran

call CCTK_Exit(istat , cctkGH, value )

integer istat
CCTK_POINTER cctkGH
integer value


Parameters

cctkGH pointer to CCTK grid hierarchy
value the return code to exit with

Discussion

This routine causes an immediate, regular termination of Cactus. It never returns to the caller.

CCTK_Abort [A27] Abort the code
CCTK_ERROR [A158] Macro to print a single string as error message and stop the code
CCTK_VError [A613] Prints a formatted string with a variable argument list as error message to standard error and stops the code
CCTK_VWarn [A630] Prints a formatted string with a variable argument list as a warning message to standard error and possibly stops the code
CCTK_WARN [A634] Macro to print a single string as a warning message and possibly stop the code

### CCTK_FirstVarIndex

Given a group name, returns the first variable index in the group.

Synopsis

C

#include "cctk.h"
int first_varindex = CCTK_FirstVarIndex(const char* group_name);


Fortran

#include "cctk.h"
integer first_varindex
character*(*) group_name
call CCTK_FirstVarIndex(first_varindex, group_name)


Result

first_varindex ($\ge$ 0) The first variable index in the group.

Parameters

group_name ($\ne$ NULL in C) For C, this is a non-NULL pointer to the character-string name of the group. For Fortran, this is the character-string name of the group. In both cases this should be of the form "implementation::group".

Discussion

If the group contains $N>0$ variables, and $V$ is the value of first_varindex returned by this function, then the group’s variables have variable indices $V$, $V+1$, $V+2$, …, $V+N-1$.

CCTK_FirstVarIndexI() Given a group index, returns the first variable index in the group.
CCTK_GroupData() Get “static” information about a group (including the number of variables in the group).
CCTK_GroupDynamicData() Get “dynamic” information about a group.

Errors

-1 Group name is invalid.
-2 Group has no members.

### CCTK_FirstVarIndexI

Given a group index, returns the first variable index in the group.

Synopsis

C

#include "cctk.h"
int first_varindex = CCTK_FirstVarIndexI(int group_index)


Fortran

#include "cctk.h"
integer first_varindex, group_index
call CCTK_FirstVarIndexI(first_varindex, group_index)


Result

first_varindex ($\ge$ 0) The first variable index in the group.

Parameters

group_index ($\ge$ 0) The group index, e.g. as returned by CCTK_GroupIndex().

Discussion

If the group contains $N>0$ variables, and $V$ is the value of first_varindex returned by this function, then the group’s variables have variable indices $V$, $V+1$, $V+2$, …, $V+N-1$.

CCTK_FirstVarIndex() Given a group name, returns the first variable index in the group.
CCTK_GroupData() Get “static” information about a group (including the number of variables in the group).
CCTK_GroupDynamicData() Get “dynamic” information about a group.

Errors

-1 Group index is invalid.
-2 Group has no members.

### CCTK_FortranString

Copy the contents of a C string into a Fortran string variable

Synopsis

C

#include "cctk.h"
int CCTK_FortranString (char const * c_string,
char       * fortran_string,
int          fortran_length);


Fortran

#include "cctk.h"
subroutine CCTK_FortranString (string_length, c_string, fortran_string)
CCTK_INT              string_length
CCTK_POINTER_TO_CONST c_string
character*(*)         fortran_string
end subroutine


Parameters

c_string This is (a pointer to) a standard C-style (NUL-terminated) string. Typically this argument is the name of a Cactus keyword or string paramameter.
fortran_string [This is an output argument] A Fortran character variable into which this function copies the C string (or as much of it as will fit).
fortran_length The length of the Fortran character variable.

Result

string_length This function sets this variable to the number of characters in the C string (not counting the terminating NUL character). If this is larger than the declared length of fortran_string then the string was truncated. If this is negative, then an error occurred.

Discussion

String or keyword parameters in Cactus are passed into Fortran routines as pointers to C strings, which can’t be directly used by Fortran code. This subroutine copies such a C string into a Fortran character*N string variable, from where it can be used by Fortran code.

Examples

Fortran

# *** this is param.ccl for some thorn ***

# This example shows how we can use a Cactus string parameter to
# specify the contents of a Cactus key/value table, or the name of
# a Fortran output file

string our_parameters "parameter string"
{
".*" :: "any string acceptable to Util_TableCreateFromString()"
} "order=3"

string output_file_name "name of our output file"
{
".*" :: "any valid file name"
} "foo.dat"

c *** this is sample Fortran code in this same thorn ***
#include "util_Table.h"
#include "cctk.h"
#include "cctk_Arguments.h"
#include "cctk_Parameters.h"

subroutine my_Fortran_subroutine(CCTK_ARGUMENTS)
DECLARE_CCTK_ARGUMENTS
DECLARE_CCTK_PARAMETERS

CCTK_INT :: string_length
integer  :: status
integer  :: table_handle

integer, parameter:: max_string_length = 500
character*max_string_length :: our_parameters_fstring
character*max_string_length :: output_file_name_fstring

c
c create Cactus key/value table from  our_parameters  parameter
c
call CCTK_FortranString(string_length,
$our_parameters,$                          our_parameters_fstring)
if (string_length .gt. max_string_length) then
call CCTK_WARN(CCTK_WARN_ALERT, "’our_parameters’ string too long!")
end if
call Util_TableCreateFromString(table_handle, our_parameters_fstring)

c
c open a Fortran output file named via  output_file_name  parameter
c
call CCTK_FortranString(string_length,
$output_file_name,$                          output_file_name_fstring)
if (string_length .gt. max_string_length) then
call CCTK_WARN(CCTK_WARN_ALERT, "’output_file_name’ string too long!")
end if
open (unit=9, iostat=status, status=’replace’,
$file=output_file_name_fstring)  See Also CCTK_FullVarName() Given a variable index, returns the full name of the variable. ### CCTK_FullGroupName Given a group index, returns the group name. Synopsis C #include <cctk.h> const char *name = CCTK_FullGroupName(int index);  Result thorn Name of group, or NULL if group index is invalid Parameters index The group index Discussion The group name must not be freed. Examples C #include <cctk.h> #include <stdio.h> int index = CCTK_GroupIndex("evolve::scalars"); const char *name = CCTK_FullGroupName(index); printf ("Group name: %s", name);  See Also CCTK_FullVarName [A181] Given a variable index, returns the variable name CCTK_GroupName [A266] Given a group index, returns the group name Errors NULL The group index is invalid. ### CCTK_FullVarName Given a variable index, returns the full name of the variable Synopsis C const char * fullname = CCTK_FullVarName( int index)  Fortran #include "cctk.h" subroutine CCTK_FullVarName(nchars, index, fullname) integer nchars integer index character*(*) fullname end subroutine CCTK_FullVarName  Parameters implementation The full variable name index The variable index Discussion The full variable name must not be freed after it has been used since the storage is maintained by the flesh. The full variable name is in the form <implementation>::<variable> for PUBLIC or PROTECTED variables and <thorn>::<variable> for PRIVATE variables. Examples C index = CCTK_VarIndex("evolve::phi"); name = CCTK_FullVarName(index); printf ("Variable name: %s", name);  See Also CCTK_FullName() Given a variable index, returns the full name of the variable. ### CCTK_FullName Given a variable index, returns the full name of the variable Synopsis C char * fullname = CCTK_FullName( int index)  Fortran #include "cctk.h" subroutine CCTK_FullName(nchars, index, fullname) integer nchars integer index character*(*) fullname end subroutine CCTK_FullName  Parameters implementation The full variable name index The variable index Discussion The full variable name must be explicitly freed after it has been used. The full variable name is in the form <implementation>::<variable> for PUBLIC or PROTECTED variables and <thorn>::<variable> for PRIVATE variables. Examples C index = CCTK_VarIndex("evolve::phi"); name = CCTK_FullName(index); printf ("Variable name: %s", name); free (name);  ### CCTK_GetClockName Given a pointer to the cTimerVal corresponding to a timer clock returns a pointer to a string that is the name of the clock Synopsis C const char * CCTK_GetClockName(val)  Parameters const cTimerVal * val timer clock value pointer Discussion Do not attempt to free the returned pointer directly. You must use the string before calling CCTK_TimerDestroyData on the containing timer info. ### CCTK_GetClockResolution Given a pointer to the cTimerVal corresponding to a timer clock returns the resolution of the clock in seconds. Synopsis C double CCTK_GetClockResolution(val)  Parameters const cTimerVal * val timer clock value pointer Discussion Ideally, the resolution should represent a good lower bound on the smallest non-zero difference between two consecutive calls of CCTK_GetClockSeconds. In practice, it is sometimes far smaller than it should be. Often it just represents the smallest value representable due to how the information is stored internally. ### CCTK_GetClockSeconds Given a pointer to the cTimerVal corresponding to a timer clock returns a the elapsed time in seconds between the preceding CCTK_TimerStart and CCTK_TimerStop as recorded by the requested clock. Synopsis C double CCTK_GetClockSeconds(val)  Parameters const cTimerVal * val timer clock value pointer Discussion Be aware, different clocks measure different things (proper time, CPU time spent on this process, etc.), and have varying resolution and accuracy. ### CCTK_GetClockValue Given a name of a clock that is in the given cTimerData structure, returns a pointer to the cTimerVal structure holding the clock’s value. Synopsis C const cTimerVal * CCTK_GetClockValue(name, info)  Parameters const char * name Name of clock const cTimerData * info Timer information structure containing clock. Discussion Do not attempt to free the returned pointer directly. Errors A null return value indicates an error. ### CCTK_GetClockValueI Given a index of a clock that is in the given cTimerData structure, returns a pointer to the cTimerVal structure holding the clock’s value. Synopsis C const cTimerVal * CCTK_GetClockValue(index, info)  Parameters int index Index of clock const cTimerData * info Timer information structure containing clock. Discussion Do not attempt to free the returned pointer directly. Errors A null return value indicates an error. ### CCTK_GFINDEX1D Given a set of multidimensional indices compute the 1-dimensional index into a grid function. Synopsis C int CCTK_GFINDEX1D(const cGH *restrict cctkGH, int i)  Parameters const cGH *restrict cctkGH The pointer to the CCTK grid hierarchy int i Index in the i direction Discussion Grid functions are held in memory as 1-dimensional C arrays. These are laid out in memory as in Fortran. Cactus provides macros to find the 1-dimensional index which is needed from the multidimensional indices which are usually used. In Fortran, grid functions are accessed as Fortran arrays. Examples C for (i=0; i<cctk_lsh[0]; i++) { int const ind1d = CCTK_GFINDEX1D(cctkGH,i); rho[ind1d] = exp(-pow(r[ind1d],2)); }  See Also CCTK_VECTGFINDEX1D() Given a set of vector and multidimensional indices compute the 1-dimensional index into a vector grid function. ### CCTK_GFINDEX2D Given a set of multidimensional indices compute the 2-dimensional index into a grid function. Synopsis C int CCTK_GFINDEX2D(const cGH *restrict cctkGH, int i, int j)  Parameters const cGH *restrict cctkGH The pointer to the CCTK grid hierarchy int i Index in the i direction int j Index in the j direction Discussion Grid functions are held in memory as 1-dimensional C arrays. These are laid out in memory as in Fortran. Cactus provides macros to find the 1-dimensional index which is needed from the multidimensional indices which are usually used. In Fortran, grid functions are accessed as Fortran arrays. Examples C for (j=0; j<cctk_lsh[1]; j++) { for (i=0; i<cctk_lsh[0]; i++) { int const ind2d = CCTK_GFINDEX2D(cctkGH,i,j); rho[ind2d] = exp(-pow(r[ind2d],2)); } }  See Also CCTK_VECTGFINDEX2D() Given a set of vector and multidimensional indices compute the 2-dimensional index into a vector grid function. ### CCTK_GFINDEX3D Given a set of multidimensional indices compute the 3-dimensional index into a grid function. Synopsis C int CCTK_GFINDEX3D(const cGH *restrict cctkGH, int i, int j, int k)  Parameters const cGH *restrict cctkGH The pointer to the CCTK grid hierarchy int i Index in the i direction int j Index in the j direction int k Index in the k direction Discussion Grid functions are held in memory as 1-dimensional C arrays. These are laid out in memory as in Fortran. Cactus provides macros to find the 1-dimensional index which is needed from the multidimensional indices which are usually used. In Fortran, grid functions are accessed as Fortran arrays. Examples C for (k=0; k<cctk_lsh[2]; k++) { for (j=0; j<cctk_lsh[1]; j++) { for (i=0; i<cctk_lsh[0]; i++) { int const ind3d = CCTK_GFINDEX3D(cctkGH,i,j,k); rho[ind3d] = exp(-pow(r[ind3d],2)); } } }  See Also CCTK_VECTGFINDEX3D() Given a set of vector and multidimensional indices compute the 3-dimensional index into a vector grid function. ### CCTK_GFINDEX4D Given a set of multidimensional indices compute the 4-dimensional index into a grid function. Synopsis C int CCTK_GFINDEX4D(const cGH *restrict cctkGH, int i, int j, int k, int l)  Parameters const cGH *restrict cctkGH The pointer to the CCTK grid hierarchy int i Index in the i direction int j Index in the j direction int k Index in the k direction int l Index in the l direction Discussion Grid functions are held in memory as 1-dimensional C arrays. These are laid out in memory as in Fortran. Cactus provides macros to find the 1-dimensional index which is needed from the multidimensional indices which are usually used. In Fortran, grid functions are accessed as Fortran arrays. Examples C for (l=0; l<cctk_lsh[3]; l++) { for (k=0; k<cctk_lsh[2]; k++) { for (j=0; j<cctk_lsh[1]; j++) { for (i=0; i<cctk_lsh[0]; i++) { int const ind4d = CCTK_GFINDEX4D(cctkGH,i,j,k,l); rho[ind4d] = exp(-pow(r[ind4d],2)); } } } }  See Also CCTK_VECTGFINDEX4D() Given a set of vector and multidimensional indices compute the 4-dimensional index into a vector grid function. ### CCTK_GHExtension Get the pointer to a registered extension to the Cactus GH structure Synopsis C void * extension = CCTK_GHExtension( const GH * cctkGH, const char * name)  Parameters extension The pointer to the GH extension cctkGH The pointer to the CCTK grid hierarchy name The name of the GH extension Discussion No Fortran routine exists at the moment. Examples C void *extension = CCTK_GHExtension(GH, "myExtension");  Errors NULL A NULL pointer is returned if an invalid extension name was given. ### CCTK_GHExtensionHandle Get the handle associated with a extension to the Cactus GH structure Synopsis C int handle = CCTK_GHExtensionHandle( const char * name)  Fortran call CCTK_GHExtensionHandle(handle , name ) integer handle character*(*) name  Parameters handle The GH extension handle group The name of the GH extension Examples C handle = CCTK_GHExtension("myExtension") ;  Fortran call CCTK_GHExtension(handle,"myExtension")  ### CCTK_GridArrayReductionOperator The name of the implementation of the registered grid array reduction operator, NULL if none is registered Synopsis C #include "cctk.h" const char *ga_reduc_imp = CCTK_GridArrayReductionOperator();  Result ga_reduc_imp Returns the name of the implementation of the registered grid array reduction operator or NULL if none is registered Discussion We only allow one grid array reduction operator currently. This function can be used to check if any grid array reduction operator has been registered. See Also CCTK_ReduceGridArrays() Performs reduction on a list of distributed grid arrays CCTK_RegisterGridArrayReductionOperator() Registers a function as a grid array reduction operator of a certain name CCTK_NumGridArrayReductionOperators() The number of grid array reduction operators registered ### CCTK_GroupbboxGI, CCTK_GroupbboxGN Given a group index or name, return an array of the bounding box of the group for each face Synopsis C #include "cctk.h" int status = CCTK_GroupbboxGI(const cGH *cctkGH, int dim, int *bbox, int groupindex); int status = CCTK_GroupbboxGN(const cGH *cctkGH, int dim, int *bbox, const char *groupname);  Fortran call CCTK_GroupbboxGI(status, cctkGH, dim, bbox, groupindex) call CCTK_GroupbboxGN(status, cctkGH, dim, bbox, groupname) integer status CCTK_POINTER cctkGH integer dim integer bbox(dim) integer groupindex character*(*) groupname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid group index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of group. bbox ($\ne$ NULL) Pointer to array which will hold the return values. groupindex Group index. groupname Group’s full name. Discussion The bounding box for a given group is returned in a user-supplied array buffer. See Also CCTK_GroupbboxVI, CCTK_GroupbboxVN Returns the lower bounds for a given variable. ### CCTK_GroupbboxVI, CCTK_GroupbboxVN Given a variable index or name, return an array of the bounding box of the variable for each face Synopsis C #include "cctk.h" int status = CCTK_GroupbboxVI(const cGH *cctkGH, int dim, int *bbox, int varindex); int status = CCTK_GroupbboxVN(const cGH *cctkGH, int dim, int *bbox, const char *varname);  Fortran call CCTK_GroupbboxVI(status, cctkGH, dim, bbox, varindex) call CCTK_GroupbboxVN(status, cctkGH, dim, bbox, varname) integer status CCTK_POINTER cctkGH integer dim integer bbox(dim) integer varindex character*(*) varname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid variable index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of variable. bbox ($\ne$ NULL) Pointer to array which will hold the return values. varindex Group index. varname Group’s full name. Discussion The bounding box for a given variable is returned in a user-supplied array buffer. See Also CCTK_GroupbboxGI, CCTK_GroupbboxGN Returns the upper bounds for a given group. ### CCTK_GroupData Given a group index, returns information about the group and its variables. Synopsis C #include "cctk.h" int status = CCTK_GroupData(int group_index, cGroup* group_data_buffer);  Result 0 success Parameters group_index The group index for which the information is desired. group_data_buffer ($\ne$ NULL) Pointer to a cGroup structure in which the information should be stored. See the ”Discussion” section below for more information about this structure. Discussion The cGroup structure2 contains (at least) the following members:3  int grouptype; /* group type, as returned by CCTK_GroupTypeNumber() */ int vartype; /* variable type, as returned by CCTK_VarTypeNumber() */ int disttype; /* distribution type, */ /* as returned by CCTK_GroupDistribNumber() */ int dim; /* dimension (rank) of the group */ /* e.g. 3 for a group of 3-D variables */ int numvars; /* number of variables in the group */ int numtimelevels; /* declared number of time levels for this group’s variables */ int vectorgroup; /* 1 if this is a vector group, 0 if it’s not */ int vectorlength; /* vector length of group */ /* (i.e. number of vector elements) */ /* (it is numvars = vectorlength * num_basevars, */ /* where num_basevars is the number of */ /* variables that have been given names in the */ /* interface.ccl) */ /* 1 if this isn’t a vector group */ int tagstable; /* handle to the group’s tags table; */ /* this is a Cactus key-value table used to store */ /* metadata about the group and its variables, */ /* such as the variables’ tensor types */  See Also "interface.ccl" Defines variables, groups, tags tables, and lots of other things. CCTK_FullGroupName [A179] Gets the group name for a given group index. CCTK_GroupDynamicData [A225] Gets grid-size information for a group’s variables. CCTK_GroupIndex [A236] Gets the group index for a given group name. CCTK_GroupIndexFromVar [A240] Gets the group index for a given variable name. CCTK_GroupName [A266] Gets the group name for a given group index. CCTK_GroupNameFromVarI [A268] Gets the group name for a given variable name. CCTK_GroupTypeI [A292] Gets a group type index for a given group index. CCTK_GroupTypeFromVarI [A288] Gets a group type index for a given variable index. Errors -1 group_index is invalid. -2 group_data_buffer is NULL. Examples C #include <stdio.h> #include "cctk.h" cGroup group_info; int group_index, status; group_index = CCTK_GroupIndex("BSSN_MoL::ADM_BSSN_metric"); if (group_index < 0) CCTK_VWarn(CCTK_WARN_ABORT, "error return %d trying to get BSSN metric’s group index!", group_index); /*NOTREACHED*/ status = CCTK_GroupData(group_index, &group_info); if (status < 0) CCTK_VWarn(CCTK_WARN_ABORT, "error return %d trying to get BSSN metric’s group information!", status); /*NOTREACHED*/ printf("this group’s arrays are %-dimensional and have %d time levels\n", group_info.dim, group_info.numtimelevels);  ### CCTK_GroupDimFromVarI Given a variable index, returns the dimension of all variables in the corresponding group. Synopsis C #include "cctk.h" int dim = CCTK_GroupDimFromVarI(int varindex);  Fortran call CCTK_GroupDimFromVarI(dim, varindex)  Result positive the dimension of the group -1 invalid variable index Parameters varindex Variable index Discussion The dimension of all variables in a group associcated with the given variable is returned. See Also CCTK_GroupDimI Returns the dimension for a given group ### CCTK_GroupDimI Given a group index, returns the dimension of that group. Synopsis C #include "cctk.h" int dim = CCTK_GroupDimI(int groupindex);  Fortran call CCTK_GroupDimI(dim, groupindex)  Result positive the dimension of the group -1 invalid group index Parameters groupindex Group index Discussion The dimension of variables in the given group is returned. See Also CCTK_GroupDimFromVarI Returns the dimension for a group given by a member variable index ### CCTK_GroupDynamicData Returns the driver’s internal data for a given group Synopsis C #include "cctk.h" int retval = CCTK_GroupDynamicData (const cGH *GH, int group, cGroupDynamicData *data);  Result 0 Sucess -1 the given pointer to the data structure data is null -3 the givenGH pointer is invalid -77 the requested group has zero variables Parameters GH a valid initialized GH structure for your driver group the index of the group you’re interested in data a pointer to a caller-supplied data structure to store the group data Discussion This function returns information about the given grid hierarchy. The data structure used to store the information in is of type cGroupDynamicData. The members of this structure that are set are: • dim: The number of dimensions in this group. • lsh: The (process-)local size. • ash: The (process-)local allocated size. • gsh: The global grid size. • lbnd: The lowest index of the local grid as seen on the global grid. (These use zero based indexing.) • ubnd: The largest index of the local grid as seen on the global grid. (These use zero based indexing.) • tile_min: The lowest index of the local grid that should be written by this thread. (These use zero based indexing.) • tile_max: The largest index minus one of the local grid that should be written by this thread. (These use zero based indexing.) • nghostzones: The number of ghostzones for each dimension. • bbox: Values indicating whether these are inter-process boundaries (0) or physical boundaries (1). • activetimelevels: The number of active time levels. - ### CCTK_GroupGhostsizesI Given a group index, return a pointer to an array containing the ghost sizes of the group in each dimension. Synopsis C #include "cctk.h" CCTK_INT **ghostsizes = CCTK_GroupGhostsizesI(int groupindex);  Result non-NULL a pointer to the ghost size array NULL invalid group index Parameters groupindex Group index Discussion The ghost sizes in each dimension for a given group are returned as a pointer reference. See Also CCTK_GroupDimI Returns the dimension for a group. CCTK_GroupSizesI Returns the size arrays for a group. ### CCTK_GroupgshGI, CCTK_GroupgshGN Given a group index or name, return an array of the global size of the group in each dimension Synopsis C #include "cctk.h" int status = CCTK_GroupgshGI(const cGH *cctkGH, int dim, int *gsh, int groupindex); int status = CCTK_GroupgshGN(const cGH *cctkGH, int dim, int *gsh, const char *groupname);  Fortran call CCTK_GroupgshGI(status, cctkGH, dim, gsh, groupindex) call CCTK_GroupgshGN(status, cctkGH, dim, gsh, groupname) integer status CCTK_POINTER cctkGH integer dim integer gsh(dim) integer groupindex character*(*) groupname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid group name Parameters cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of group. gsh ($\ne$ NULL) Pointer to array which will hold the return values. groupindex Index of the group. groupname Name of the group. Discussion The global size in each dimension for a given group is returned in a user-supplied array buffer. See Also CCTK_GroupgshVI, CCTK_GroupgshVN Returns the global size for a given variable. CCTK_GrouplshGI, CCTK_GrouplshGN Returns the local size for a given group. CCTK_GrouplshVI, CCTK_GrouplshVN Returns the local size for a given variable. CCTK_GroupashGI, CCTK_GroupashGN Returns the local allocated size for a given group. CCTK_GroupashVI, CCTK_GroupashVN Returns the local allocated size for a given variable. ### CCTK_GroupgshVI, CCTK_GroupgshVN Given a variable index or its full name, return an array of the global size of the variable in each dimension Synopsis C #include "cctk.h" int status = CCTK_GroupgshVI(const cGH *cctkGH, int dim, int *gsh, int varindex); int status = CCTK_GroupgshVN(const cGH *cctkGH, int dim, int *gsh, const char *varname);  Fortran call CCTK_GroupgshVI(status, cctkGH, dim, gsh, varindex) call CCTK_GroupgshVN(status, cctkGH, dim, gsh, varname) integer status CCTK_POINTER cctkGH integer dim integer gsh(dim) integer varindex chararacter*(*) varname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid variable index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of variable. gsh ($\ne$ NULL) Pointer to array which will hold the return values. varindex Variable index. varname Variable’s full name. Discussion The global size in each dimension for a given variable is returned in a user-supplied array buffer. See Also CCTK_GroupgshGI, CCTK_GroupgshGN Returns the global size for a given group. CCTK_GrouplshGI, CCTK_GrouplshGN Returns the local size for a given group. CCTK_GrouplshVI, CCTK_GrouplshVN Returns the local size for a given variable. CCTK_GroupashGI, CCTK_GroupashGN Returns the local size for a given group. CCTK_GroupashVI, CCTK_GroupashVN Returns the local size for a given variable. ### CCTK_GroupIndex Get the index number for a group name Synopsis C int index = CCTK_GroupIndex( const char * groupname)  Fortran call CCTK_GroupIndex(index , groupname ) integer index character*(*) groupname  Parameters groupname The name of the group Discussion The group name should be the given in its fully qualified form, that is <implementation>::<group> for a public or protected group, and <thornname>::<group> for a private group. Examples C index = CCTK_GroupIndex("evolve::scalars");  Fortran call CCTK_GroupIndex(index,"evolve::scalars")  ### CCTK_GroupIndexFromVar Given a variable name, returns the index of the associated group Synopsis C int groupindex = CCTK_GroupIndexFromVar( const char * name)  Fortran call CCTK_GroupIndexFromVar(groupindex , name ) integer groupindex character*(*) name  Parameters groupindex The index of the group name The full name of the variable Discussion The variable name should be in the form <implementation>::<variable> Examples C groupindex = CCTK_GroupIndexFromVar("evolve::phi") ;  Fortran call CCTK_GROUPINDEXFROMVAR(groupindex,"evolve::phi")  ### CCTK_GroupIndexFromVarI Given a variable index, returns the index of the associated group Synopsis C int groupindex = CCTK_GroupIndexFromVarI( int varindex)  Fortran call CCTK_GroupIndexFromVarI(groupindex , varindex ) integer groupindex integer varindex  Parameters groupindex The index of the group varindex The index of the variable Examples C index = CCTK_VarIndex("evolve::phi"); groupindex = CCTK_GroupIndexFromVarI(index);  Fortran call CCTK_VARINDEX("evolve::phi") CCTK_GROUPINDEXFROMVARI(groupindex,index)  ### CCTK_GrouplbndGI, CCTK_GrouplbndGN Given a group index or name, return an array of the lower bounds of the group in each dimension Synopsis C #include "cctk.h" int status = CCTK_GrouplbndGI(const cGH *cctkGH, int dim, int *lbnd, int groupindex); int status = CCTK_GrouplbndGN(const cGH *cctkGH, int dim, int *lbnd, const char *groupname);  Fortran call CCTK_GrouplbndGI(status, cctkGH, dim, lbnd, groupindex) call CCTK_GrouplbndGN(status, cctkGH, dim, lbnd, groupname) integer status CCTK_POINTER cctkGH integer dim integer lbnd(dim) integer groupindex character*(*) groupname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid group index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of group. lbnd ($\ne$ NULL) Pointer to array which will hold the return values. groupindex Group index. groupname Group’s full name. Discussion The lower bounds in each dimension for a given group is returned in a user-supplied array buffer. See Also CCTK_GrouplbndVI, CCTK_GrouplbndVN Returns the lower bounds for a given variable. CCTK_GroupubndGI, CCTK_GroupubndGN Returns the upper bounds for a given group. CCTK_GroupubndVI, CCTK_GroupubndVN Returns the upper bounds for a given variable. ### CCTK_GrouplbndVI, CCTK_GrouplbndVN Given a variable index or name, return an array of the lower bounds of the variable in each dimension Synopsis C #include "cctk.h" int status = CCTK_GrouplbndVI(const cGH *cctkGH, int dim, int *lbnd, int varindex); int status = CCTK_GrouplbndVN(const cGH *cctkGH, int dim, int *lbnd, const char *varname);  Fortran call CCTK_GrouplbndVI(status, cctkGH, dim, lbnd, varindex) call CCTK_GrouplbndVN(status, cctkGH, dim, lbnd, varname) integer status CCTK_POINTER cctkGH integer dim integer lbnd(dim) integer varindex character*(*) varname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid variable index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of variable. lbnd ($\ne$ NULL) Pointer to array which will hold the return values. varindex Group index. varname Group’s full name. Discussion The lower bounds in each dimension for a given variable is returned in a user-supplied array buffer. See Also CCTK_GrouplbndGI, CCTK_GrouplbndGN Returns the lower bounds for a given group. CCTK_GroupubndGI, CCTK_GroupubndGN Returns the upper bounds for a given group. CCTK_GroupubndVI, CCTK_GroupubndVN Returns the upper bounds for a given variable. ### CCTK_GrouplshGI, CCTK_GrouplshGN Given a group index or name, return an array of the local size of the group in each dimension Synopsis C #include "cctk.h" int status = CCTK_GrouplshGI(const cGH *cctkGH, int dim, int *lsh, int groupindex); int status = CCTK_GrouplshGN(const cGH *cctkGH, int dim, int *lsh, const char *groupname);  Fortran call CCTK_GrouplshGI(status, cctkGH, dim, lsh, groupindex) call CCTK_GrouplshGN(status, cctkGH, dim, lsh, groupname) integer status CCTK_POINTER cctkGH integer dim integer lsh(dim) integer groupindex character*(*) groupname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid group name Parameters cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of group. lsh ($\ne$ NULL) Pointer to array which will hold the return values. groupindex Index of the group. groupname Name of the group. Discussion The local size in each dimension for a given group is returned in a user-supplied array buffer. See Also CCTK_GroupgshGI, CCTK_GroupgshGN Returns the global size for a given group. CCTK_GroupgshVI, CCTK_GroupgshVN Returns the global size for a given variable. CCTK_GrouplshVI, CCTK_GrouplshVN Returns the local size for a given variable. CCTK_GroupashGI, CCTK_GroupashGN Returns the local allocated size for a given group. CCTK_GroupashVI, CCTK_GroupashVN Returns the local allocated size for a given variable. ### CCTK_GrouplshVI, CCTK_GrouplshVN Given a variable index or its full name, return an array of the local size of the variable in each dimension Synopsis C #include "cctk.h" int status = CCTK_GrouplshVI(const cGH *cctkGH, int dim, int *lsh, int varindex); int status = CCTK_GrouplshVN(const cGH *cctkGH, int dim, int *lsh, const char *varname);  Fortran call CCTK_GrouplshVI(status, cctkGH, dim, lsh, varindex) call CCTK_GrouplshVN(status, cctkGH, dim, lsh, varname) integer status CCTK_POINTER cctkGH integer dim integer lsh(dim) integer varindex character*(*) varname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid variable index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of variable. lsh ($\ne$ NULL) Pointer to array which will hold the return values. varindex Variable index. varname Variable’s full name. Discussion The local size in each dimension for a given variable is returned in a user-supplied array buffer. See Also CCTK_GroupgshGI, CCTK_GroupgshGN Returns the global size for a given group. CCTK_GroupgshVI, CCTK_GroupgshVN Returns the global size for a given variable. CCTK_GrouplshGI, CCTK_GrouplshGN Returns the local size for a given group. CCTK_GroupashGI, CCTK_GroupashGN Returns the local allocated size for a given group. CCTK_GroupashVI, CCTK_GroupashVN Returns the local allocated size for a given variable. ### CCTK_GroupashGI, CCTK_GroupashGN Given a group index or name, return an array of the local allocated size of the group in each dimension Synopsis C #include "cctk.h" int status = CCTK_GroupashGI(const cGH *cctkGH, int size, int *ash, int groupindex); int status = CCTK_GroupashGN(const cGH *cctkGH, int size, int *ash, const char *groupname);  Fortran call CCTK_GroupashGI(status, cctkGH, size, ash, groupindex) call CCTK_GroupashGN(status, cctkGH, size, ash, groupname) integer status CCTK_POINTER cctkGH integer size integer ash(size) integer groupindex character*(*) groupname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid group name Parameters cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. size ($\ge 1$) Size of output array, should be at least dimension of group. ash ($\ne$ NULL) Pointer to array which will hold the return values. groupindex Index of the group. groupname Name of the group. Discussion The local allocated size in each dimension for a given group is returned in a user-supplied array buffer. See Also CCTK_GroupgshGI, CCTK_GroupgshGN Returns the global size for a given group. CCTK_GroupgshVI, CCTK_GroupgshVN Returns the global size for a given variable. CCTK_GrouplshGI, CCTK_GrouplshGN Returns the local size for a given group. CCTK_GrouplshVI, CCTK_GrouplshVN Returns the local size for a given variable. CCTK_GroupashVI, CCTK_GroupashVN Returns the local allocated size for a given variable. ### CCTK_GroupashVI, CCTK_GroupashVN Given a variable index or its full name, return an array of the local allocated size of the variable in each dimension Synopsis C #include "cctk.h" int status = CCTK_GroupashVI(const cGH *cctkGH, int size, int *ash, int varindex); int status = CCTK_GroupashVN(const cGH *cctkGH, int size, int *ash, const char *varname);  Fortran call CCTK_GroupashVI(status, cctkGH, size, ash, varindex) call CCTK_GroupashVN(status, cctkGH, size, ash, varname) integer status CCTK_POINTER cctkGH integer size integer ash(size) integer varindex character*(*) varname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid variable index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. size ($\ge 1$) Size of output array, should be at least dimension of group. ash ($\ne$ NULL) Pointer to array which will hold the return values. varindex Variable index. varname Variable’s full name. Discussion The local allocated size in each dimension for a given variable is returned in a user-supplied array buffer. See Also CCTK_GroupgshGI, CCTK_GroupgshGN Returns the global size for a given group. CCTK_GroupgshVI, CCTK_GroupgshVN Returns the global size for a given variable. CCTK_GrouplshGI, CCTK_GrouplshGN Returns the local size for a given group. CCTK_GrouplshVI, CCTK_GrouplshVN Returns the local size for a given variable. CCTK_GroupashGI, CCTK_GroupashGN Returns the local allocated size for a given group. ### CCTK_GroupName Given a group index, returns the group name Synopsis C char * name = CCTK_GroupName( int index)  Parameters name The group name index The group index Discussion The group name must be explicitly freed after it has been used. Examples C index = CCTK_GroupIndex("evolve::scalars"); name = CCTK_GroupName(index); printf ("Group name: %s", name); free (name);  ### CCTK_GroupNameFromVarI Given a variable index, return the name of the associated group Synopsis C char * group = CCTK_GroupNameFromVarI(int varindex)  Parameters group The name of the group varindex The index of the variable Examples C index = CCTK_VarIndex("evolve::phi"); group = CCTK_GroupNameFromVarI(index) ;  ### CCTK_GroupnghostzonesGI, CCTK_GroupnghostzonesGN Given a group index or name, return an array with the number of ghostzones in each dimension of the group Synopsis C #include "cctk.h" int status = CCTK_GroupnghostzonesGI(const cGH *cctkGH, int dim, int *nghostzones, int groupindex) int status = CCTK_GroupnghostzonesGN(const cGH *cctkGH, int dim, int *nghostzones, const char *groupname)  Fortran call CCTK_GroupnghostzonesGI(status, cctkGH, dim, nghostzones, groupindex) call CCTK_GroupnghostzonesGN(status, cctkGH, dim, nghostzones, groupname) integer status CCTK_POINTER cctkGH integer dim integer nghostzones(dim) integer groupindex character*(*) groupname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of group. nghostzones ($\ne$ NULL) Pointer to array which will hold the return values. groupindex Group index. groupname Group name. Discussion The number of ghostzones in each dimension for a given group is returned in a user-supplied array buffer. See Also CCTK_GroupnghostzonesVI, CCTK_GroupnghostzonesVN Returns the number of ghostzones for a given variable. ### CCTK_GroupnghostzonesVI, CCTK_GroupnghostzonesVN Given a variable index or its full name, return an array with the number of ghostzones in each dimension of the variable Synopsis C #include "cctk.h" int status = CCTK_GroupnghostzonesVI(const cGH *cctkGH, int dim, int *nghostzones, int varindex) int status = CCTK_GroupnghostzonesVN(const cGH *cctkGH, int dim, int *nghostzones, const char *varname)  Fortran call CCTK_GroupnghostzonesVI(status, cctkGH, dim, nghostzones, varindex) call CCTK_GroupnghostzonesVN(status, cctkGH, dim, nghostzones, varname) integer status CCTK_POINTER cctkGH integer dim integer nghostzones(dim) integer varindex character*(*) varname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of group. nghostzones ($\ne$ NULL) Pointer to array which will hold the return values. varindex Variable index. varname Variable’s full name. Discussion The number of ghostzones in each dimension for a given variable is returned in a user-supplied array buffer. See Also CCTK_GroupnghostzonesGI, CCTK_GroupnghostzonesGN Returns the number of ghostzones for a given group. ### CCTK_GroupSizesI Given a group index, return a pointer to an array containing the sizes of the group in each dimension. Synopsis C #include "cctk.h" CCTK_INT **ghostsizes = CCTK_GroupSizesI(int groupindex);  Result non-NULL a pointer to the size array NULL invalid group index Parameters groupindex Group index Discussion The sizes in each dimension for a given group are returned as a pointer reference. See Also CCTK_GroupDimI Returns the dimension for a group. CCTK_GroupGhostsizesI Returns the size arrays for a group. ### CCTK_GroupStorageDecrease Decrease the number of timelevels allocated for the given variable groups. Synopsis C int numTL = CactusDefaultGroupStorageDecrease (const cGH *GH, int n_groups, const int *groups, const int *timelevels, int *status);  Result The new total number of timelevels with storage enabled for all groups queried or modified. Parameters GH pointer to grid hierarchy n_groups Number of groups groups list of group indices to reduce storage for timelevels number of time levels to reduce storage for for each group groups list of group indices to allocate storage for status optional return array which, if not NULL, will, on return, contain the number of timelevels which were previously allocated storage for each group Discussion The decrease group storage routine decreases the memory allocated to the specified number of timelevels for each listed group, returning the previous number of timelevels enabled for that group in the status array, if that is not NULL. It never increases the number of timelevels enabled, i.e., if it is asked to reduce to more timelevels than are enabled, it does not change the storage for that group. There is a default implementation which checks for the presence of the older DisableGroupStorage function, and if that is not available it flags an error. If it is available it makes a call to it, and puts its return value in the status flag for the group. Usually, a driver has overloaded the default implementation. A driver should replace the appropriate GV pointers on the cGH structure when it changes the storage state of a GV. ### CCTK_GroupStorageIncrease Increases the number of timelevels allocated for the given variable groups. Synopsis C int numTL = CactusDefaultGroupStorageIncrease (const cGH *GH, int n_groups, const int *groups, const int *timelevels, int *status);  Result The new total number of timelevels with storage enabled for all groups queried or modified. Parameters GH pointer to grid hierarchy n_groups Number of groups groups list of group indices to allocate storage for timelevels number of time levels to allocate storage for for each group groups list of group indices to allocate storage for status optional return array which, if not NULL, will, on return, contain the number of timelevels which were previously allocated storage for each group Discussion The increase group storage routine increases the allocated memory to the specified number of timelevels of each listed group, returning the previous number of timelevels enabled for that group in the status array, if that is not NULL. It never decreases the number of timelevels enabled, i.e., if it is asked to enable less timelevels than are already enabled it does not change the storage for that group. There is a default implementation which checks for the presence of the older EnableGroupStorage function, and if that is not available it flags an error. If it is available it makes a call to it, and puts its return value in the status flag for the group. Usually, a driver has overloaded the default implementation. A driver should replace the appropriate GV pointers on the cGH structure when it changes the storage state of a GV. ### CCTK_GroupTagsTable Given a group name, return the table handle of the group’s tags table. Synopsis C #include "cctk.h" int table_handle = CCTK_GroupTagsTable(const char* group_name);  Fortran #include "cctk.h" integer table_handle character*(*) group_name call CCTK_VarIndex(table_handle, group_name)  Result table_handle The table handle of the group’s tags table. Parameters group_name The character-string name of group. This should be given in its fully qualified form, that is implementation::group_name or thorn_name::group_name. See Also CCTK_GroupData [A215] This function returns a variety of “static” information about a group (“static” in the sense that it doesn’t change during a Cactus run). CCTK_GroupDynamicData [A225] This function returns a variety of “dynamic” information about a group (“dynamic” in the sense that a driver can (and often does) change this information during a Cactus run). Errors -1 no group exists with the specified name ### CCTK_GroupTagsTableI Given a group name, return the table handle of the group’s tags table. Synopsis C #include "cctk.h" int table_handle = CCTK_GroupTagsTableI(int group_index);  Fortran #include "cctk.h" integer table_handle integer group_index call CCTK_VarIndex(table_handle, group_index)  Result table_handle The table handle of the group’s tags table. Parameters group_index The group index of the group. See Also CCTK_GroupData [A215] This function returns a variety of “static” information about a group (“static” in the sense that it doesn’t change during a Cactus run). CCTK_GroupDynamicData [A225] This function returns a variety of “dynamic” information about a group (“dynamic” in the sense that a driver can (and often does) change this information during a Cactus run). CCTK_GroupIndex [A236] Get the group index for a specified group name. CCTK_GroupIndexFromVar [A240] Get the group index for the group containing the variable with a specified name. CCTK_GroupIndexFromVarI [A244] Get the group index for the group containing the variable with a specified variable index. Errors -1 no group exists with the specified name ### CCTK_GroupTypeFromVarI Provides a group’s group type index given a variable index Synopsis C int type = CCTK_GroupTypeFromVarI( int index)  Fortran call CCTK_GroupTypeFromVarI(type , index ) integer type integer index  Parameters type The group’s group type index group The variable index Discussion The group’s group type index indicates the type of variables in the group. Either scalars, grid functions or arrays. The group type can be checked with the Cactus provided macros for CCTK_SCALAR, CCTK_GF, CCTK_ARRAY. Examples C index = CCTK_GroupIndex("evolve::scalars") array = (CCTK_ARRAY == CCTK_GroupTypeFromVarI(index));  Fortran call CCTK_GROUPTYPEFROMVARI(type,3)  ### CCTK_GroupTypeI Provides a group’s group type index given a group index Synopsis C #include "cctk.h" int group_type = CCTK_GroupTypeI(int group);  Result -1 -1 is returned if the given group index is invalid. Parameters group Group index. Discussion A group’s group type index indicates the type of variables in the group. The three group types are scalars, grid functions, and grid arrays. The group type can be checked with the Cactus provided macros for CCTK_SCALAR, CCTK_GF, CCTK_ARRAY. See Also CCTK_GroupTypeFromVarI [A288] This function takes a variable index rather than a group index as its argument. ### CCTK_GroupubndGI, CCTK_GroupubndGN Given a group index or name, return an array of the upper bounds of the group in each dimension Synopsis C #include "cctk.h" int status = CCTK_GroupubndGI(const cGH *cctkGH, int dim, int *ubnd, int groupindex); int status = CCTK_GroupubndGN(const cGH *cctkGH, int dim, int *ubnd, const char *groupname);  Fortran call CCTK_GroupubndGI(status, cctkGH, dim, ubnd, groupindex) call CCTK_GroupubndGN(status, cctkGH, dim, ubnd, groupname) integer status CCTK_POINTER cctkGH integer dim integer ubnd(dim) integer groupindex character*(*) groupname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid group index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of group. ubnd ($\ne$ NULL) Pointer to array which will hold the return values. groupindex Group index. groupname Group’s full name. Discussion The upper bounds in each dimension for a given group is returned in a user-supplied array buffer. See Also CCTK_GrouplbndGI, CCTK_GrouplbndGN Returns the lower bounds for a given group. CCTK_GrouplbndVI, CCTK_GrouplbndVN Returns the lower bounds for a given variable. CCTK_GroupubndVI, CCTK_GroupubndVN Returns the upper bounds for a given variable. ### CCTK_GroupubndVI, CCTK_GroupubndVN Given a variable index or name, return an array of the upper bounds of the variable in each dimension Synopsis C #include "cctk.h" int status = CCTK_GroupubndVI(const cGH *cctkGH, int dim, int *ubnd, int varindex); int status = CCTK_GroupubndVN(const cGH *cctkGH, int dim, int *ubnd, const char *varname);  Fortran call CCTK_GroupubndVI(status, cctkGH, dim, ubnd, varindex) call CCTK_GroupubndVN(status, cctkGH, dim, ubnd, varname) integer status CCTK_POINTER cctkGH integer dim integer ubnd(dim) integer varindex character*(*) varname  Result 0 success -1 incorrect dimension supplied -2 data not available from driver -3 called on a scalar group -4 invalid variable index Parameters status Return value. cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dim ($\ge 1$) Number of dimensions of variable. ubnd ($\ne$ NULL) Pointer to array which will hold the return values. varindex Group index. varname Group’s full name. Discussion The upper bounds in each dimension for a given variable is returned in a user-supplied array buffer. See Also CCTK_GrouplbndGI, CCTK_GrouplbndGN Returns the lower bounds for a given group. CCTK_GrouplbndVI, CCTK_GrouplbndVN Returns the lower bounds for a given variable. CCTK_GroupubndGI, CCTK_GroupubndGN Returns the upper bounds for a given group. ### CCTK_ImpFromVarI Given a variable index, returns the implementation name Synopsis C char * implementation = CCTK_ImpFromVarI( int index)  Parameters implementation The implementation name if the argument is the index of a public or protected variable, the thorn name otherwise. index The variable index Discussion No Fortran routine exists at the moment Examples C index = CCTK_VarIndex("evolve::phi"); implementation = CCTK_ImpFromVarI(index);  ### CCTK_ImplementationRequires Return the ancestors for an implementation. Synopsis C #include "cctk.h" uStringList *imps = CCTK_ImplementationRequires(const char *imp);  Result imps (not documented) Parameters imp (not documented) See Also CCTK_ActivatingThorn [A32] Finds the thorn which activated a particular implementation CCTK_CompiledImplementation [A79] Return the name of the compiled implementation with given index CCTK_CompiledThorn [A81] Return the name of the compiled thorn with given index CCTK_ImplementationThorn [A304] Returns the name of one thorn providing an implementation. CCTK_ImpThornList [A306] Return the thorns for an implementation CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration CCTK_NumCompiledImplementations [A378] Return the number of implementations compiled in CCTK_NumCompiledThorns [A380] Return the number of thorns compiled in CCTK_ThornImplementation [A554] Returns the implementation provided by the thorn Errors (not documented) ### CCTK_ImplementationThorn Returns the name of one thorn providing an implementation. Synopsis C #include "cctk.h" const char *thorn = CCTK_ImplementationThorn(const char *name);  Result thorn Name of the thorn or NULL Parameters name Name of the implementation See Also CCTK_ActivatingThorn [A32] Finds the thorn which activated a particular implementation CCTK_CompiledImplementation [A79] Return the name of the compiled implementation with given index CCTK_CompiledThorn [A81] Return the name of the compiled thorn with given index CCTK_ImplementationRequires [A302] Return the ancestors for an implementation CCTK_ImpThornList [A306] Return the thorns for an implementation CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration CCTK_NumCompiledImplementations [A378] Return the number of implementations compiled in CCTK_NumCompiledThorns [A380] Return the number of thorns compiled in CCTK_ThornImplementation [A554] Returns the implementation provided by the thorn Errors NULL Error. ### CCTK_ImpThornList Return the thorns for an implementation. Synopsis C #include "cctk.h" t_sktree *thorns = CCTK_ImpThornList(const char *name);  Result thorns (not documented) Parameters name Name of implementation Discussion (not documented) See Also CCTK_ActivatingThorn [A32] Finds the thorn which activated a particular implementation CCTK_CompiledImplementation [A79] Return the name of the compiled implementation with given index CCTK_CompiledThorn [A81] Return the name of the compiled thorn with given index CCTK_ImplementationRequires [A302] Return the ancestors for an implementation CCTK_ImplementationThorn [A304] Returns the name of one thorn providing an implementation. CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration CCTK_NumCompiledImplementations [A378] Return the number of implementations compiled in CCTK_NumCompiledThorns [A380] Return the number of thorns compiled in CCTK_ThornImplementation [A554] Returns the implementation provided by the thorn Errors (not documented) ### CCTK_INFO Macro to print a single string as an information message to screen Synopsis C #include <cctk.h> CCTK_INFO(const char *message);  Fortran #include "cctk.h" call CCTK_INFO(message) character*(*) message  Parameters message The string to print as an info message Discussion This macro can be used by thorns to print a single string as an info message to screen. The macro CCTK_INFO(message) expands to a call to the underlying function CCTK_Info: CCTK_Info(CCTK_THORNSTRING, message)  So the macro automatically includes the name of the originating thorn in the info message. It is recommended that the macro CCTK_INFO is used to print a message rather than calling CCTK_Info directly. To include variables in an info message from C, you can use the routine CCTK_VInfo which accepts a variable argument list. To include variables from Fortran, a string must be constructed and passed in a CCTK_INFO macro. See Also CCTK_ERROR [A158] macro to print an error message with a single string argument and stop the code CCTK_VERROR [A610] macro to print a formatted string with a variable argument list as error message and stops the code CCTK_VINFO() [A616] macro to print a formatted string with a variable argument list as an info message to screen CCTK_VWARN [A626] macro to print a warning message with a variable argument list CCTK_WARN [A634] macro to print a warning message with a single string argument and possibly stop the code Examples C #include <cctk.h> CCTK_INFO("Output is disabled");  Fortran #include "cctk.h" integer myint real myreal character*200 message write(message, ’(A32, G12.7, A5, I8)’) & ’Your info message, including ’, myreal, ’ and ’, myint call CCTK_INFO(message)  ### CCTK_Info Function to print a single string as an information message to screen Synopsis C #include <cctk.h> CCTK_Info(const char *thorn, const char *message);  Fortran #include "cctk.h" call CCTK_INFO(thorn, message) character*(*) thorn, message  Parameters message The string to print as an info message Discussion The macro CCTK_INFO automatically includes the name of the originating thorn in the info message. It is recommended that the macro CCTK_INFO is used to print a message rather than calling CCTK_Info directly. See Also CCTK_ERROR [A158] macro to print an error message with a single string argument and stop the code CCTK_VERROR [A610] macro to print a formatted string with a variable argument list as error message and stops the code CCTK_VINFO [A616] macro to print a formatted string with a variable argument list as an info message to screen CCTK_VWARN [A626] macro to print a warning message with a variable argument list CCTK_WARN [A634] macro to print a warning message with a single string argument and possibly stop the code Examples C #include <cctk.h> CCTK_INFO("Output is disabled");  Fortran #include "cctk.h" integer myint real myreal character*200 message write(message, ’(A32, G12.7, A5, I8)’) & ’Your info message, including ’, myreal, ’ and ’, myint call CCTK_INFO(message)  ### CCTK_InfoCallbackRegister Register one or more routines for dealing with information messages in addition to printing them to screen Synopsis C #include <cctk.h> CCTK_InfoCallbackRegister(void *data, cctk_infofunc callback);  Parameters data The void pointer holding extra information about the registered call back routine callback The function pointer pointing to the call back function dealing with information messages. The definition of the function pointer is:  typedef void (*cctk_infofunc)(const char *thorn, const char *message, void *data);  The argument list is the same as those in CCTK_Info() (see the discussion of CCTK_INFO() page A308) except an extra void pointer to hold the information about the call back routine. Discussion This function can be used by thorns to register their own routines to deal with information messages. The registered function pointers will be stored in a pointer chain. When CCTK_VInfo() is called, the registered routines will be called in the same order as they get registered in addition to dumping warning messages to stderr. The function can only be called in C. See Also CCTK_VInfo() prints a formatted string with a variable argument list as an info message to screen CCTK_WarnCallbackRegister Register one or more routines for dealing with warning messages in addition to printing them to standard error Examples C /*DumpInfo will dump information messages to a file*/ void DumpInfo(const char *thorn, const char *message, void *data) { DECLARE_CCTK_PARAMETERS FILE *fp; char *str = (char *)malloc((strlen(thorn) +strlen(message) +100)*sizeof(char)); /*info_dump_file is a string set in the parameter file*/ if((fp = fopen (info_dump_file, "a"))==0) { fprintf(stderr, "fatal error: can not open the file %s\n",info_dump_file); return; } sprintf(str, "\n[INFO]\nThorn->%s\nMsg->%s\n",thorn,message); fprintf(fp, "%s", str); free(str); fclose(fp); } ... /*data = NULL; callback = DumpInfo*/ CCTK_InfoCallbackRegister(NULL,DumpInfo);  ### CCTK_InterpGridArrays Interpolate a list of distributed grid variables The computation is optimized for the case of interpolating a number of grid variables at a time; in this case all the interprocessor communication can be done together, and the same interpolation coefficients can be used for all the variables. A grid variable can be either a grid function or a grid array. Synopsis C #include "cctk.h" int status = CCTK_InterpGridArrays(const cGH *cctkGH, int N_dims, int local_interp_handle, int param_table_handle, int coord_system_handle, int N_interp_points, const int interp_coords_type_code, const void *const interp_coords[], int N_input_arrays, const CCTK_INT input_array_variable_indices[], int N_output_arrays, const CCTK_INT output_array_type_codes[], void *const output_arrays[]);  Fortran call CCTK_InterpGridArrays(status, . cctkGH, . N_dims, . local_interp_handle, param_table_handle, . coord_system_handle, . N_interp_points, . interp_coords_type_code, interp_coords, . N_input_arrays, input_array_variable_indices, . N_output_arrays, output_array_type_codes, . output_arrays) integer status CCTK_POINTER cctkGH integer local_interp_handle, param_table_handle, coord_system_handle integer N_dims, N_interp_points, N_input_arrays, N_output_arrays CCTK_POINTER interp_coords(N_dims) integer interp_coords_type_code CCTK_INT input_array_variable_indices(N_input_arrays) CCTK_INT output_array_type_codes(N_output_arrays) CCTK_POINTER output_arrays(N_output_arrays)  Result 0 success < 0 indicates an error condition (see Errors) Parameters cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. N_dims ($\ge 1$) Number of dimensions in which to interpolate. This must be $\le$ the dimensionality of the coordinate system defined by coord_system_handle. The default case is that it’s $=$; see the discussion of the interpolation_hyperslab_handle parameter-table entry for the $<$ case. local_interp_handle ($\ge 0$) Handle to the local interpolation operator as returned by CCTK_InterpHandle. param_table_handle ($\ge 0$) Handle to a key-value table containing zero or more additional parameters for the interpolation operation. The table is allowed to be modified by the local and/or global interpolation routine(s). coord_system_handle ($\ge 0$) Cactus coordinate system handle defining the mapping between (usually floating-point) coordinates and integer grid subscripts, as returned by CCTK_CoordSystemHandle. N_interp_points ($\ge 0$) The number of interpolation points requested by this processor. interp_coords_type_code One of the CCTK_VARIABLE_* type codes, giving the data type of the interpolation-point coordinate arrays pointed to by interp_coords[]. All interpolation-point coordinate arrays must be of the same data type. (In practice, this data type will almost always be CCTK_REAL or one of the CCTK_REAL* types.) interp_coords ($\ne$ NULL) (Pointer to) an array of N_dims pointers to 1-D arrays giving the coordinates of the interpolation points requested by this processor. These coordinates are with respect to the coordinate system defined by coord_system_handle. N_input_arrays ($\ge 0$) The number of input variables to be interpolated. If N_input_arrays is zero then no interpolation is done; such a call may be useful for setup, interpolator querying, etc. Note that if the parameter table entry operand_indices is used to specify a nontrivial (e.g. one-to-many) mapping of input variables to output arrays, only the unique set of input variables should be given here. input_array_variable_indices ($\ne$ NULL) (Pointer to) an array of N_input_arrays CCTK grid variable indices (as returned by CCTK_VarIndex) specifying the input grid variables for the interpolation. For any element with an index value of -1 in the grid variable indices array, that interpolation is skipped. This may be useful if the main purpose of the call is e.g. to do some query or setup computation. N_output_arrays ($\ge 0$) The number of output arrays to be returned from the interpolation. If N_output_arrays is zero then no interpolation is done; such a call may be useful for setup, interpolator querying, etc. Note that N_output_arrays may differ from N_input_arrays, e.g. if the operand_indices parameter-table entry is used to specify a nontrivial (e.g. many-to-one) mapping of input variables to output arrays. If such a mapping is specified, only the unique set of output arrays should be given in the output_arrays argument. output_array_type_codes ($\ne$ NULL) (Pointer to) an array of N_output_arrays CCTK_VARIABLE_* type codes giving the data types of the 1-D output arrays pointed to by output_arrays[]. output_arrays ($\ne$ NULL) (Pointer to) an array of N_output_arrays pointers to the (user-supplied) 1-D output arrays for the interpolation. If any of the pointers in the output_arrays array is NULL, then that interpolation is skipped. This may be useful if the main purpose of the call is e.g. to do some query or setup computation. Discussion This function interpolates a list of CCTK grid variables (in a multiprocessor run these are generally distributed over processors) on a list of interpolation points. The grid topology and coordinates are implicitly specified via a Cactus coordinate system. The interpolation points may be anywhere in the global Cactus grid. In a multiprocessor run they may vary from processor to processor; each processor will get whatever interpolated data it asks for. The routine CCTK_InterpGridArrays does not do the actual interpolation itself but rather takes care of whatever interprocessor communication may be necessary, and – for each processor’s local patch of the domain-decomposed grid variables – calls CCTK_InterpLocalUniform to invoke an external local interpolation operator (as identified by an interpolation handle). Additional parameters for the interpolation operation of both CCTK_InterpGridArrays and CCTK_InterpLocalUniform can be passed in via a handle to a key/value options table. All interpolation operators should check for a parameter table entry with the key suppress_warnings which – if present – indicates that the caller wants the interpolator to be silent in case of an error condition and only return an appropriate error code. One common parameter-table option, which a number of interpolation operators are likely to support, is order, a CCTK_INT specifying the order of the (presumably polynomial) interpolation (1=linear, 2=quadratic, 3=cubic, etc). As another example, a table might be used to specify that the local interpolator should take derivatives, by specifying const CCTK_INT operand_indices[N_output_arrays]; const CCTK_INT operation_codes[N_output_arrays];  Also, the global interpolator will typically need to specify some options of its own for the local interpolator.4 These will overwrite any entries with the same keys in the param_table_handle table. Finally, the parameter table can be used to pass back arbitrary information by the local and/or global interpolation routine(s) by adding/modifying appropriate key/value pairs. Note that CCTK_InterpGridArrays is a collective operation, so in the multiprocessor case you must call this function in parallel on each processor, passing identical arguments except for the number of interpolation points, the interpolation coordinates, and the output array pointers. You may (and typically will) specify a different set of interpolation points on each processor’s call – you may even specify an empty set on some processors. The interpolation points may be “owned” by any processors (this function takes care of all interprocessor-communication issues), though it may be more efficient to have most or all of the interpolation points “owned” by the current processor. In the multiprocessor case, the result returned by CCTK_InterpGridArrays is guaranteed to be the same on all processors. (All current implementations simply take the minimum of the per-processor results over all processors; this gives a result which is 0 if all processors succeeded, or which is the most negative error code encountered by any processor otherwise.) The semantics of CCTK_InterpGridArrays are mostly independent of which Cactus driver is being used, but an implementation will most likely depend on, and make use of, driver-specific internals. For that reason, CCTK_InterpGridArrays is made an overloadable function. The Cactus flesh will supply only a dummy routine for it which – if called – does nothing but print a warning message saying that it wasn’t overloaded by another thorn, and stop the code. So one will always need to compile in and activate a driver-specific thorn which provides an interpolation routine for CCTK grid variables and properly overloads CCTK_InterpGridArrays with it at startup. Details of the operation performed, and what (if any) inputs and/or outputs are specified in the parameter table, depend on which driver-specific interpolation thorn and interpolation operator (provided by a local interpolation thorn) you use. See the documentation on individual interpolator thorns (e.g. PUGHInterp in the CactusPUGH arrangement, CarpetInterp in the Carpet arrangement, LocalInterp in the CactusBase arrangement, and/or AEILocalInterp in the AEIThorns arrangement) for details. Note that in a multiprocessor Cactus run, it’s the user’s responsibility to choose the interprocessor ghost-zone size (driver::ghost_size) large enough so that the local interpolator never has to off-center its molecules near interprocessor boundaries. (This ensures that the interpolation results are independent of the interprocessor decomposition, at least up to floating-point roundoff errors.) If the ghost-zone size is too small, the interpolator should return the CCTK_ERROR_INTERP_GHOST_SIZE_TOO_SMALL error code. See Also CCTK_InterpHandle() Get the interpolator handle for a given character-string name. CCTK_InterpLocalUniform() Interpolate a list of processor-local arrays which define a uniformly-spaced data grid Errors The following list of error codes indicates specific error conditions. For the complete list of possible error return codes you should refer to the ThornGuide’s chapter of the corresponding interpolation thorn(s) you are using. To find the numerical values of the error codes (or more commonly, to find which error code corresponds to a given numerical value), look in the files cctk_Interp.h, util_ErrorCodes.h, and/or util_Table.h in the src/include/ directory in the Cactus flesh. CCTK_ERROR_INTERP_POINT_OUTSIDE one or more of the interpolation points is out of range (in this case additional information about the out-of-range point may be reported through the parameter table; see the Thorn Guide for whatever thorn provides the local interpolation operator for further details) CCTK_ERROR_INTERP_GRID_TOO_SMALL one or more of the dimensions of the input arrays is/are smaller than the molecule size chosen by the interpolator (based on the parameter-table options, e.g. the interpolation order) CCTK_ERROR_INTERP_GHOST_SIZE_TOO_SMALL for a multi-processor run, the size of the interprocessor boundaries (the ghostzone size) is smaller than the molecule size chosen by the interpolator (based on the parameter-table options, e.g. the interpolation order). This error code is also returned if a processor’s chunk of the global grid is smaller than the actual molecule size. UTIL_ERROR_BAD_INPUT one or more of the input arguments is invalid (e.g. NULL pointer) UTIL_ERROR_NO_MEMORY unable to allocate memory UTIL_ERROR_BAD_HANDLE parameter table handle is invalid other error codes this function may also return any error codes returned by the Util_Table* routines used to get parameters from (and/or set results in) the parameter table Examples Here’s a simple example to do quartic 3-D interpolation of a real and a complex grid array, at 1000 interpolation points: C #include "cctk.h" #include "util_Table.h" #define N_DIMS 3 #define N_INTERP_POINTS 1000 #define N_INPUT_ARRAYS 2 #define N_OUTPUT_ARRAYS 2 const cGH *GH; int operator_handle, coord_system_handle; /* interpolation points */ CCTK_REAL interp_x[N_INTERP_POINTS], interp_y[N_INTERP_POINTS], interp_z[N_INTERP_POINTS]; const void *interp_coords[N_DIMS]; /* input and output arrays */ CCTK_INT input_array_variable_indices[N_INPUT_ARRAYS]; static const CCTK_INT output_array_type_codes[N_OUTPUT_ARRAYS] = { CCTK_VARIABLE_REAL, CCTK_VARIABLE_COMPLEX }; void *output_arrays[N_OUTPUT_ARRAYS]; CCTK_REAL output_for_real_array [N_INTERP_POINTS]; CCTK_COMPLEX output_for_complex_array[N_INTERP_POINTS]; operator_handle = CCTK_InterpHandle("generalized polynomial interpolation"); if (operator_handle < 0) { CCTK_WARN(CCTK_WARN_ABORT, "can’t get operator handle!"); } coord_system_handle = CCTK_CoordSystemHandle("cart3d"); if (coord_system_handle < 0) { CCTK_WARN(CCTK_WARN_ABORT, "can’t get coordinate-system handle!"); } interp_coords[0] = (const void *) interp_x; interp_coords[1] = (const void *) interp_y; interp_coords[2] = (const void *) interp_z; input_array_variable_indices[0] = CCTK_VarIndex("my_thorn::real_array"); input_array_variable_indices[1] = CCTK_VarIndex("my_thorn::complex_array"); output_arrays[0] = (void *) output_for_real_array; output_arrays[1] = (void *) output_for_complex_array; if (CCTK_InterpGridArrays(GH, N_DIMS, operator_handle, Util_TableCreateFromString("order=4"), coord_system_handle, N_INTERP_POINTS, CCTK_VARIABLE_REAL, interp_coords, N_INPUT_ARRAYS, input_array_variable_indices, N_OUTPUT_ARRAYS, output_array_type_codes, output_arrays) < 0) { CCTK_WARN(CCTK_WARN_ABORT, "error return from interpolator!"); }  ### CCTK_InterpHandle Return the handle for a given interpolation operator Synopsis C int handle = CCTK_InterpHandle( const char * operator)  Fortran call CCTK_InterpHandle(handle , operator ) integer handle character*(*) operator  Parameters handle Handle for the interpolation operator operator Name of interpolation operator Examples C handle = CCTK_InterpHandle("my interpolation operator");  Fortran call CCTK_InterpHandle(handle,"my interpolation operator")  Errors negative A negative value is returned for invalid/unregistered interpolation operator names. ### CCTK_InterpLocalUniform Interpolate a list of processor-local arrays which define a uniformly-spaced data grid The computation is optimized for the case of interpolating a number of arrays at a time; in this case the same interpolation coefficients can be used for all the arrays. Synopsis C #include "util_ErrorCodes.h" #include "cctk.h" int status = CCTK_InterpLocalUniform(int N_dims, int operator_handle, int param_table_handle, const CCTK_REAL coord_origin[], const CCTK_REAL coord_delta[], int N_interp_points, int interp_coords_type_code, const void *const interp_coords[], int N_input_arrays, const CCTK_INT input_array_dims[], const CCTK_INT input_array_type_codes[], const void *const input_arrays[], int N_output_arrays, const CCTK_INT output_array_type_codes[], void *const output_arrays[]);  Fortran call CCTK_InterpLocalUniform(status, . N_dims, . operator_handle, . param_table_handle, . coord_origin, . coord_delta, . N_interp_points, . interp_coords_type_code, . interp_coords, . N_input_arrays, . input_array_dims, . input_array_type_codes, . input_arrays, . N_output_arrays, . output_array_type_codes, . output_arrays) integer status integer operator_handle, param_table_handle integer N_dims, N_interp_points, N_input_arrays, N_output_arrays CCTK_REAL coord_origin(N_dims), coord_delta(N_dims) integer interp_coords_type_code CCTK_POINTER interp_coords(N_dims) CCTK_INT input_array_dims(N_dims), input_array_type_codes(N_input_arrays) CCTK_POINTER input_arrays(N_input_arrays) CCTK_INT output_array_type_codes(N_output_arrays) CCTK_POINTER output_arrays(N_output_arrays)  Result 0 success Parameters N_dims ($\ge 1$) Number of dimensions in which to interpolate. Note that this may be less than the number of dimensions of the input arrays if the storage is set up appropriately. For example, we might want to interpolate along 1-D lines or in 2-D planes of a 3-D input array; here N_dims would be 1 or 2 respectively. For details, see the section on “Non-Contiguous Input Arrays” in the Thorn Guide for thorn AEILocalInterp. operator_handle ($\ge 0$) Handle to the interpolation operator as returned by CCTK_InterpHandle. param_table_handle ($\ge 0$) Handle to a key-value table containing additional parameters for the interpolator. One common parameter-table option, which a number of interpolation operators are likely to support, is order, a CCTK_INT specifying the order of the (presumably polynomial) interpolation (1=linear, 2=quadratic, 3=cubic, etc). See the Thorn Guide for the AEILocalInterp thorn for other parameters. coord_origin ($\ne$ NULL) (Pointer to) an array giving the coordinates of the data point with integer array subscripts 0, 0, …, 0, or more generally (if the actual array bounds don’t include the all-zeros-subscript point) the coordinates which this data point would have if it existed. See the “Discussion” section below for more on how coord_origin[] is actually used. coord_delta ($\ne$ NULL) (Pointer to) an array giving the coordinate spacing of the data arrays. See the “Discussion” section below for more on how coord_delta[] is actually used. N_interp_points ($\ge 0$) The number of points at which interpolation is to be done. interp_coords_type_code One of the CCTK_VARIABLE_* type codes, giving the data type of the 1-D interpolation-point-coordinate arrays pointed to by interp_coords[]. (In practice, this data type will almost always be CCTK_REAL or one of the CCTK_REAL* types.) interp_coords ($\ne$ NULL) (Pointer to) an array of N_dims pointers to 1-D arrays giving the coordinates of the interpolation points. These coordinates are with respect to the coordinate system defined by coord_origin[] and coord_delta[]. N_input_arrays ($\ge 0$) The number of input arrays to be interpolated. Note that if the parameter table entry operand_indices is used to specify a 1-to-many mapping of input arrays to output arrays, only the unique set of input arrays should be given here. input_array_dims ($\ne$ NULL) (Pointer to) an array of N_dims integers giving the dimensions of the N_dims-D input arrays. By default all the input arrays are taken to have these dimensions, with [0] the most contiguous axis and [N_dims-1] the least contiguous axis, and array subscripts in the range 0 <= subscript < input_array_dims[axis]. See the discussion of the input_array_strides optional parameter (passed in the parameter table) for details of how this can be overridden. input_array_type_codes ($\ne$ NULL) (Pointer to) an array of N_input_arrays CCTK_VARIABLE_* type codes giving the data types of the N_dims-D input arrays pointed to by input_arrays[]. input_arrays ($\ne$ NULL) (Pointer to) an array of N_input_arrays pointers to the N_dims-D input arrays for the interpolation. If any input_arrays[in] pointer is NULL, that interpolation is skipped. N_output_arrays ($\ge 0$) The number of output arrays to be returned from the interpolation. output_array_type_codes ($\ne$ NULL) (Pointer to) an array of N_output_arrays CCTK_VARIABLE_* type codes giving the data types of the 1-D output arrays pointed to by output_arrays[]. output_arrays ($\ne$ NULL) (Pointer to) an array of N_output_arrays pointers to the (user-supplied) 1-D output arrays for the interpolation. If any output_arrays[out] pointer is NULL, that interpolation is skipped. Discussion CCTK_InterpLocalUniform is a generic API for interpolating processor-local arrays when the data points’ $xyz$ coordinates are linear functions of the integer array subscripts ijk (we’re describing this for 3-D, but the generalization to other numbers of dimensions should be obvious). The coord_origin[] and coord_delta[] arguments specify these linear functions: The $\left(x,y,z\right)$ coordinates are used for the interpolation (i.e. the interpolator may internally use polynomials in these coordinates); interp_coords[] specifies coordinates in this same coordinate system. Details of the operation performed, and what (if any) inputs and/or outputs are specified in the parameter table, depend on which interpolation operator you use. See the Thorn Guide for the AEILocalInterp thorn for further discussion. See Also CCTK_InterpHandle() Get the interpolator handle for a given character-string name. CCTK_InterpGridArrays() Interpolate a list of Cactus grid arrays CCTK_InterpRegisterOpLocalUniform() Register a CCTK_InterpLocalUniform interpolation operator CCTK_InterpLocalNonUniform() Interpolate a list of processor-local arrays, with non-uniformly spaced data points. Errors To find the numerical values of the error codes (or more commonly, to find which error code corresponds to a given numerical value), look in the files cctk_Interp.h, util_ErrorCodes.h, and/or util_Table.h in the src/include/ directory in the Cactus flesh. CCTK_ERROR_INTERP_POINT_OUTSIDE one or more of the interpolation points is out of range (in this case additional information about the out-of-range point may be reported through the parameter table; see the Thorn Guide for the AEILocalInterp thorn for further details) CCTK_ERROR_INTERP_GRID_TOO_SMALL one or more of the dimensions of the input arrays is/are smaller than the molecule size chosen by the interpolator (based on the parameter-table options, e.g. the interpolation order) UTIL_ERROR_BAD_INPUT one or more of the inputs is invalid (e.g. NULL pointer) UTIL_ERROR_NO_MEMORY unable to allocate memory UTIL_ERROR_BAD_HANDLE parameter table handle is invalid other error codes this function may also return any error codes returned by the Util_Table* routines used to get parameters from (and/or set results in) the parameter table Examples Here’s a simple example of interpolating a CCTK_REAL and a CCTK_COMPLEX $10×20$ 2-D array, at 5 interpolation points, using cubic interpolation. Note that since C allows arrays to be initialized only if the initializer values are compile-time constants, we have to declare the interp_coords[], input_arrays[], and output_arrays[] arrays as non-const, and set their values with ordinary (run-time) assignment statements. In C++, there’s no restriction on initializer values, so we could declare the arrays const and initialize them as part of their declarations. C #define N_DIMS 2 #define N_INTERP_POINTS 5 #define N_INPUT_ARRAYS 2 #define N_OUTPUT_ARRAYS 2 /* (x,y) coordinates of data grid points */ #define X_ORIGIN ... #define X_DELTA ... #define Y_ORIGIN ... #define Y_DELTA ... const CCTK_REAL origin[N_DIMS] = { X_ORIGIN, Y_ORIGIN }; const CCTK_REAL delta [N_DIMS] = { X_DELTA, Y_DELTA }; /* (x,y) coordinates of interpolation points */ const CCTK_REAL interp_x[N_INTERP_POINTS]; const CCTK_REAL interp_y[N_INTERP_POINTS]; const void *interp_coords[N_DIMS]; /* see note above */ /* input arrays */ /* ... note Cactus uses Fortran storage ordering, i.e.\ X is contiguous */ #define NX 10 #define NY 20 const CCTK_REAL input_real [NY][NX]; const CCTK_COMPLEX input_complex[NY][NX]; const CCTK_INT input_array_dims[N_DIMS] = { NX, NY }; const CCTK_INT input_array_type_codes[N_INPUT_ARRAYS] = { CCTK_VARIABLE_REAL, CCTK_VARIABLE_COMPLEX }; const void *input_arrays[N_INPUT_ARRAYS]; /* see note above */ /* output arrays */ CCTK_REAL output_real [N_INTERP_POINTS]; CCTK_COMPLEX output_complex[N_INTERP_POINTS]; const CCTK_INT output_array_type_codes[N_OUTPUT_ARRAYS] = { CCTK_VARIABLE_REAL, CCTK_VARIABLE_COMPLEX }; void *const output_arrays[N_OUTPUT_ARRAYS]; /* see note above */ int operator_handle, param_table_handle; operator_handle = CCTK_InterpHandle("my interpolation operator"); if (operator_handle < 0) CCTK_WARN(CCTK_WARN_ABORT, "can’t get interpolation handle!"); param_table_handle = Util_TableCreateFromString("order=3"); if (param_table_handle < 0) CCTK_WARN(CCTK_WARN_ABORT, "can’t create parameter table!"); /* initialize the rest of the parameter arrays */ interp_coords[0] = (const void *) interp_x; interp_coords[1] = (const void *) interp_y; input_arrays[0] = (const void *) input_real; input_arrays[1] = (const void *) input_complex; output_arrays[0] = (void *) output_real; output_arrays[1] = (void *) output_complex; /* do the actual interpolation, and check for error returns */ if (CCTK_InterpLocalUniform(N_DIMS, operator_handle, param_table_handle, origin, delta, N_INTERP_POINTS, CCTK_VARIABLE_REAL, interp_coords, N_INPUT_ARRAYS, input_array_dims, input_array_type_codes, input_arrays, N_OUTPUT_ARRAYS, output_array_type_codes, output_arrays) < 0) CCTK_WARN(CCTK_WARN_ABORT, "error return from interpolator!");  ### CCTK_InterpRegisterOpLocalUniform Register a CCTK_InterpLocalUniform interpolation operator. Synopsis C #include "cctk.h" int CCTK_InterpRegisterOpLocalUniform(cInterpOpLocalUniform operator_ptr, const char *operator_name, const char *thorn_name);  Result handle ($\ge 0$) A cactus handle to refer to all interpolation operators registered under this operator name. Parameters operator_ptr ($\ne$ NULL) Pointer to the CCTK_InterpLocalUniform interpolation operator. This argument must be a C function pointer of the appropriate type; the typedef can be found in src/include/cctk_Interp.h in the Cactus source code. operator_name ($\ne$ NULL) (Pointer to) a (C-style null-terminated) character string giving the name under which to register the operator. thorn_name ($\ne$ NULL) (Pointer to) a (C-style null-terminated) character string giving the name of the thorn which provides the interpolation operator. Discussion Only C functions (or other routines with C-compatible calling sequences) can be registered as interpolation operators. See Also CCTK_InterpHandle() Get the interpolator handle for a given character-string name. CCTK_InterpLocalUniform() Interpolate a list of processor-local arrays, with uniformly spaced data points. Errors -1 NULL pointer was passed as interpolation operator routine -2 interpolation handle could not be allocated -3 Interpolation operator with this name already exists Examples C /* prototype for function we want to register */ int AEILocalInterp_InterpLocalUniform(int N_dims, int param_table_handle, /***** coordinate system *****/ const CCTK_REAL coord_origin[], const CCTK_REAL coord_delta[], /***** interpolation points *****/ int N_interp_points, int interp_coords_type_code, const void *const interp_coords[], /***** input arrays *****/ int N_input_arrays, const CCTK_INT input_array_dims[], const CCTK_INT input_array_type_codes[], const void *const input_arrays[], /***** output arrays *****/ int N_output_arrays, const CCTK_INT output_array_type_codes[], void *const output_arrays[]); /* register it! */ CCTK_InterpRegisterOpLocalUniform(AEILocalInterp_InterpLocalUniform, "generalized polynomial interpolation", CCTK_THORNSTRING);  ### CCTK_IsFunctionAliased Reports whether an aliased function has been provided Synopsis C int istat = CCTK_IsFunctionAliased( const char * functionname)  Fortran call CCTK_IsFunctionAliased(istat , functionname ) integer istat character*(*) functionname  Parameters istat the return status functionname the name of the function to check Discussion This function returns a non-zero value if the function given by functionname is provided by any active thorn, and zero otherwise. ### CCTK_IsImplementationActive Reports whether an implementation was activated in a parameter file Synopsis C int istat = CCTK_IsImplementationActive( const char * implementationname)  Fortran CCTK_IsImplementationActive( istat, implementationname ) integer istat character*(*) implementationname  Parameters istat the return status implementationname the name of the implementation to check Discussion This function returns a non-zero value if the implementation given by implementationname was activated in a parameter file, and zero otherwise. See also CCTK_ActivatingThorn [A32], CCTK_CompiledImplementation [A79], CCTK_CompiledThorn [A81], CCTK_ImplementationRequires [A302], CCTK_ImplementationThorn [A304], CCTK_ImpThornList [A306], CCTK_IsImplementationCompiled [A348], CCTK_IsThornActive [A350], CCTK_NumCompiledImplementations [A378], CCTK_NumCompiledThorns [A380], CCTK_ThornImplementation [A554]. ### CCTK_IsImplementationCompiled Reports whether an implementation was compiled into the configuration Synopsis C int istat = CCTK_IsImplementationCompiled( const char * implementationname)  Fortran istat = CCTK_IsImplementationCompiled( implementationname ) integer istat character*(*) implementationname  Parameters istat the return status implementationname the name of the implementation to check Discussion This function returns a non-zero value if the implementation given by implementationname was compiled into the configuration, and zero otherwise. See also CCTK_ActivatingThorn [A32], CCTK_CompiledImplementation [A79], CCTK_CompiledThorn [A81], CCTK_ImplementationRequires [A302], CCTK_ImplementationThorn [A304], CCTK_ImpThornList [A306], CCTK_IsImplementationActive [A346], CCTK_IsThornActive [A350], CCTK_IsThornCompiled [A353], CCTK_NumCompiledImplementations [A378], CCTK_NumCompiledThorns [A380], CCTK_ThornImplementation [A554]. ### CCTK_IsThornActive Reports whether a thorn was activated in a parameter file Synopsis C #include "cctk.h" int status = CCTK_IsThornActive(const char* thorn_name);  Fortran #include "cctk.h" integer status character *(*) thorn_name status = CCTK_IsThornActive(thorn_name)  Result status This function returns a non-zero value if thorn thorn_name was activated in a parameter file, and zero otherwise. Parameters thorn_name The character-string name of the thorn, for example ”SymBase”. Discussion This function lets you find out at run-time whether or not a given thorn is active in the current Cactus run. ### CCTK_IsThornCompiled Reports whether a thorn was activated in a parameter file Synopsis C int istat = CCTK_IsThornCompiled( const char * thornname)  Fortran istat = CCTK_IsThornCompiled( thornname ) integer istat character*(*) thornname  Parameters istat the return status thorname the name of the thorn to check Discussion This function returns a non-zero value if the implementation given by thornname was compiled into the configuration, and zero otherwise. ### CCTK_LocalArrayReduceOperator Returns the name of a registered reduction operator Synopsis C #include "cctk.h" const char *name = CCTK_LocalArrayReduceOperator(int handle);  Result name Returns the name of a registered local reduction operator of handle handle or NULL if the handle is invalid Parameters handle The handle of a registered local reduction operator Discussion This function returns the name of a registered reduction operator given its handle. NULL is returned if the handle is invalid See Also CCTK_ReduceLocalArrays() Reduces a list of local arrays (new local array reduction API) CCTK_LocalArrayReductionHandle() Returns the handle of a given local array reduction operator CCTK_RegisterLocalArrayReductionOperator() Registers a function as a reduction operator of a certain name CCTK_LocalArrayReduceOperatorImplementation() Provide the implementation which provides an local array reduction operator CCTK_NumLocalArrayReduceOperators() The number of local reduction operators registered ### CCTK_LocalArrayReduceOperatorImplementation Provide the implementation which provides an local array reduction operator Synopsis C #include "cctk.h" const char *implementation = CCTK_LocalArrayReduceOperatorImplementation( int handle);  Result implementation The name of the implementation implementing the local reduction operator of handle handle Parameters handle The handle of a registered local reduction operator Discussion This function returns the implementation name of a registered reduction operator given its handle or NULL if the handle is invalid See Also CCTK_ReduceLocalArrays() Reduces a list of local arrays (new local array reduction API) CCTK_LocalArrayReductionHandle() Returns the handle of a given local array reduction operator CCTK_RegisterLocalArrayReductionOperator() Registers a function as a reduction operator of a certain name CCTK_LocalArrayReduceOperator() Returns the name of a registered reduction operator CCTK_NumLocalArrayReduceOperators() The number of local reduction operators registered ### CCTK_LocalArrayReductionHandle Returns the handle of a given local array reduction operator Synopsis C #include "cctk.h" int handle = CCTK_LocalArrayReductionHandle(const char *operator);  Result handle The handle corresponding to the local reduction operator Parameters operator The reduction operation to be performed. If no matching registered operator is found, a warning is issued and an error returned. Discussion This function returns the handle of the local array reduction operator. The local reduction handle is also used in the grid array reduction. See Also CCTK_ReduceLocalArrays() Reduces a list of local arrays (new local array reduction API) CCTK_RegisterLocalArrayReductionOperator() Registers a function as a reduction operator of a certain name CCTK_LocalArrayReduceOperatorImplementation() Provide the implementation which provides an local array reduction operator CCTK_LocalArrayReduceOperator() Returns the name of a registered reduction operator CCTK_NumLocalArrayReduceOperators() The number of local reduction operators registered ### CCTK_MaxActiveTimeLevels Returns the maximum number of time levels ever active for a group. Synopsis C #include "cctk.h" int timelevels = CCTK_MaxActiveTimeLevels(const cGH *cctkGH, const char *groupname); int timelevels = CCTK_MaxActiveTimeLevelsGI(const cGH *cctkGH, int groupindex); int timelevels = CCTK_MaxActiveTimeLevelsGN(const cGH *cctkGH, const char *groupname); int timelevels = CCTK_MaxActiveTimeLevelsVI(const cGH *cctkGH, int varindex); int timelevels = CCTK_MaxActiveTimeLevelsVN(const cGH *cctkGH, const char *varname);  Fortran #include "cctk.h" subroutine CCTK_MaxActiveTimeLevels(timelevels, cctkGH, groupname) integer timelevels CCTK_POINTER cctkGH character*(*) groupname end subroutine CCTK_MaxActiveTimeLevels subroutine CCTK_MaxActiveTimeLevelsGI(timelevels, cctkGH, groupindex) integer timelevels CCTK_POINTER cctkGH integer groupindex end subroutine CCTK_MaxActiveTimeLevelsGI subroutine CCTK_MaxActiveTimeLevelsGN(timelevels, cctkGH, groupname) integer timelevels CCTK_POINTER cctkGH character*(*) groupname end subroutine CCTK_MaxActiveTimeLevelsGN subroutine CCTK_MaxActiveTimeLevelsVI(timelevels, cctkGH, varindex) integer timelevels CCTK_POINTER cctkGH integer varindex end subroutine CCTK_MaxActiveTimeLevelsVI subroutine CCTK_MaxActiveTimeLevelsVN(timelevels, cctkGH, varname) integer timelevels CCTK_POINTER cctkGH character*(*) varname end subroutine CCTK_MaxActiveTimeLevelsVN  Result timelevels The largest number of timelevels that were ever active for the group or the result of CCTK_DeclaredTimeLevels, whichever is larger. Parameters GH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. groupname Name of the group. groupindex Index of the group. varname Name of a variable in the group. varindex Index of a variable in the group. Discussion This function returns the number of timelevels for which storage has ever been request either through an actual storage request or via the TIMELEVELS attribute in interface.ccl. This is always at least as large as CCTK_DeclaredTimeLevels. See Also CCTK_DeclaredTimeLevels [A121] Return the maximum number of timelevels in interface.ccl. CCTK_GroupStorageDecrease [A278] Base function, overloaded by the driver, which decreases the number of active timelevels, and also returns the number of active timelevels. CCTK_GroupStorageIncrease [A280] Base function, overloaded by the driver, which increases the number of active timelevels, and also returns the number of active timelevels. Errors timelevels $<$ 0 Illegal arguments given. ### CCTK_MaxDim Get the maximum dimension of any grid variable Synopsis C int dim = CCTK_MaxDim()  Fortran call CCTK_MaxDim(dim ) integer dim  Parameters dim The maximum dimension Discussion Note that the maximum dimension will depend only on the active thorn list, and not the compiled thorn list. Examples C dim = CCTK_MaxDim()  Fortran call CCTK_MaxDim(dim)  ### CCTK_MaxGFDim Get the maximum dimension of all grid functions Synopsis C int dim = CCTK_MaxGFDim()  Fortran call CCTK_MaxGFDim(dim ) integer dim  Parameters dim The maximum dimension of all grid functions Discussion Note that the maximum dimension will depend only on the active thorn list, and not the compiled thorn list. Examples C dim = CCTK_MaxGFDim();  Fortran call CCTK_MaxGFDim(dim)}  ### CCTK_MaxTimeLevels Decprecated. Use CCTK_DeclaredTimeLevels instead. Synopsis C This function has been superseeded by A2. ### CCTK_MyProc Returns the number of the local processor for a parallel run Synopsis C int myproc = CCTK_MyProc( const cGH * cctkGH)  Parameters cctkGH pointer to CCTK grid hierarchy Discussion For a single processor run this call will return zero. For multiprocessor runs, this call will return 0 $\le$ myproc $<$ CCTK_nProcs(cctkGH). Calling CCTK_MyProc(NULL) is safe (it will not crash). Current drivers (PUGH, Carpet) handle this case correctly (i.e. CCTK_MyProc(NULL) returns a correct result), but only a “best effort” is guaranteed for future drivers (or future revisions of current drivers). ### CCTK_nProcs Returns the number of processors being used for a parallel run Synopsis C int nprocs = CCTK_nProcs( const cGH * cctkGH)  Fortran nprocs = CCTK_nProcs( cctkGH ) integer nprocs CCTK_POINTER cctkGH  Parameters cctkGH pointer to CCTK grid hierarchy Discussion For a single processor run this call will return one. Calling CCTK_nProcs(NULL) is safe (it will not crash). Current drivers (PUGH, Carpet) handle this case correctly (i.e. CCTK_nProcs(NULL) returns a correct result), but only a “best effort” is guaranteed for future drivers (or future revisions of current drivers). ### CCTK_NullPointer Returns a C-style NULL pointer value. Synopsis Fortran #include "cctk.h" CCTK_POINTER pointer_var pointer_var = CCTK_NullPointer()  Result pointer_var a CCTK_POINTER type variable which is initialized with a C-style NULL pointer Discussion Fortran doesn’t know the concept of pointers so problems arise when a C function is to be called which expects a pointer as one (or more) of it(s) argument(s). In order to pass a NULL pointer from Fortran to C, a local CCTK_POINTER variable should be used which has been initialized before with CCTK_NullPointer. Note that there is only a Fortran wrapper available for CCTK_NullPointer. See Also CCTK_PointerTo() Returns the address of a variable passed in by reference from a Fortran routine. Examples Fortran #include "cctk.h" integer ierror, table_handle CCTK_POINTER pointer_var pointer_var = CCTK_NullPointer() call Util_TableCreate(table_handle, 0) call Util_TableSetPointer(ierror, table_handle, pointer_var, "NULL pointer")  ### CCTK_NumCompiledImplementations Return the number of implementations compiled in. Synopsis C #include "cctk.h" int numimpls = CCTK_NumCompiledImplementations();  Result numimpls Number of implementations compiled in. See Also CCTK_ActivatingThorn [A32] Finds the thorn which activated a particular implementation CCTK_CompiledImplementation [A79] Return the name of the compiled implementation with given index CCTK_CompiledThorn [A81] Return the name of the compiled thorn with given index CCTK_ImplementationRequires [A302] Return the ancestors for an implementation CCTK_ImplementationThorn [A304] Returns the name of one thorn providing an implementation. CCTK_ImpThornList [A306] Return the thorns for an implementation CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration CCTK_NumCompiledThorns [A380] Return the number of thorns compiled in CCTK_ThornImplementation [A554] Returns the implementation provided by the thorn ### CCTK_NumCompiledThorns Return the number of thorns compiled in. Synopsis C #include "cctk.h" int numthorns = CCTK_NumCompiledThornss();  Result numthorns Number of thorns compiled in. See Also CCTK_ActivatingThorn [A32] Finds the thorn which activated a particular implementation CCTK_CompiledImplementation [A79] Return the name of the compiled implementation with given index CCTK_CompiledThorn [A81] Return the name of the compiled thorn with given index CCTK_ImplementationRequires [A302] Return the ancestors for an implementation CCTK_ImplementationThorn [A304] Returns the name of one thorn providing an implementation. CCTK_ImpThornList [A306] Return the thorns for an implementation CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration CCTK_NumCompiledImplementations [A378] Return the number of implementations compiled in CCTK_ThornImplementation [A554] Returns the implementation provided by the thorn ### CCTK_NumGridArrayReductionOperators The number of grid array reduction operators registered Synopsis C #include "cctk.h" int num_ga_reduc = CCTK_NumGridArrayReductionOperators();  Result num_ga_reduc The number of registered grid array reduction operators (currently either 1 or 0) Discussion This function returns the number of grid array reduction operators. Since we only allow one grid array reduction operator currently, this function can be used to check if a grid array reduction operator has been registered or not. See Also CCTK_ReduceGridArrays() Performs reduction on a list of distributed grid arrays CCTK_RegisterGridArrayReductionOperator() Registers a function as a grid array reduction operator of a certain name CCTK_GridArrayReductionOperator() The name of the grid reduction operator, or NULL if none is registered ### CCTK_NumGroups Get the number of groups of variables compiled in the code Synopsis C int number = CCTK_NumGroups()  Fortran call CCTK_NumGroups(number ) integer number  Parameters number The number of groups compiled from the thorns interface.ccl files Examples C number = CCTK_NumGroups();  Fortran call CCTK_NumGroups(number);  ### CCTK_NumIOMethods Find the total number of I/O methods registered with the flesh Synopsis C int num_methods = CCTK_NumIOMethods (void);  Fortran call CCTK_NumIOMethods (num_methods) integer num_methods  Parameters num_methods number of registered IO methods Discussion Returns the total number of IO methods registered with the flesh. ### CCTK_NumLocalArrayReduceOperators The number of local reduction operators registered Synopsis C #include "cctk.h" int num_ga_reduc = CCTK_NumLocalArrayReduceOperators();  Result num_ga_reduc The number of registered local array operators Discussion This function returns the total number of registered local array reduction operators See Also CCTK_ReduceLocalArrays() Reduces a list of local arrays (new local array reduction API) CCTK_LocalArrayReductionHandle() Returns the handle of a given local array reduction operator CCTK_RegisterLocalArrayReductionOperator() Registers a function as a reduction operator of a certain name CCTK_LocalArrayReduceOperatorImplementation() Provide the implementation which provides an local array reduction operator CCTK_LocalArrayReduceOperator() Returns the name of a registered reduction operator ### CCTK_NumReductionArraysGloballyOperators The number of global array reduction operators registered, either 1 or 0. Synopsis C #include "cctk.h" int num_reduc = CCTK_NumReductionArraysGloballyOperators();  Result num_reduc The number of registered global array operators Discussion This function returns the total number of registered global array reduction operators, it is either 1 or 0 as we do not allow multiple array reductions. See Also CCTK_ReduceArraysGlobally() Reduces a list of arrays globally CCTK_LocalArrayReductionHandle() Returns the handle of a given local array reduction operator CCTK_RegisterReduceArraysGloballyOperator() Registers a function as a reduction operator of a certain name ### CCTK_NumTimerClocks Given a cTimerData structure, returns its number of clocks. Synopsis C int err = CCTK_NumTimerClocks(info)  Parameters const cTimerData * info The timer information structure whose clocks are to be counted. ### CCTK_NumVars Get the number of grid variables compiled in the code Synopsis C int number = CCTK_NumVars()  Fortran call CCTK_NumVars(number ) integer number  Parameters number The number of grid variables compiled from the thorn’s interface.ccl files Examples C number = CCTK_NumVars();  Fortran call CCTK_NumVars(number)  ### CCTK_NumVarsInGroup Provides the number of variables in a group from the group name Synopsis C int num = CCTK_NumVarsInGroup( const char * name)  Fortran call CCTK_NumVarsInGroup(num , name ) integer num character*(*) name  Parameters num The number of variables in the group group The full group name Discussion The group name should be given in the form <implementation>::<group> Examples C numvars = CCTK_NumVarsInGroup("evolve::scalars")  Fortran call CCTK_NUMVARSINGROUP(numvars,"evolve::scalars")  ### CCTK_NumVarsInGroupI Provides the number of variables in a group from the group index Synopsis C int num = CCTK_NumVarsInGroupI( int index)  Fortran call CCTK_NumVarsInGroupI(num , index ) integer num integer index  Parameters num The number of variables in the group group The group index Discussion Examples C index = CCTK_GroupIndex("evolve::scalars")} firstvar = CCTK_NumVarsInGroupI(index)  Fortran call CCTK_NUMVARSINGROUPI(firstvar,3)  ### CCTK_OutputGH Output all variables living on the GH looping over all registered IO methods. Synopsis C int istat = CCTK_OutputGH (const cGH *cctkGH);  Fortran call CCTK_OutputGH (istat, cctkGH) integer istat CCTK_POINTER cctkGH  Parameters istat total number of variables for which output was done by all IO methods cctkGH pointer to CCTK grid hierarchy Discussion The IO methods decide themselfes whether it is time to do output now or not. Errors 0 it wasn’t time to output anything yet by any IO method -1 if no IO methods were registered ### CCTK_OutputVar Output a single variable by all I/O methods Synopsis C int istat = CCTK_OutputVar (const cGH *cctkGH, const char *variable);  Fortran call CCTK_OutputVar (istat, cctkGH, variable) integer istat CCTK_POINTER cctkGH character*(*) variable  Parameters istat return status cctkGH pointer to CCTK grid hierarchy variable full name of variable to output, with an optional options string in curly braces Discussion The output should take place if at all possible. If the appropriate file exists the data is appended, otherwise a new file is created. Errors 0 for success negative for some error condition (e.g. IO method is not registered) ### CCTK_OutputVarAs Output a single variable as an alias by all I/O methods Synopsis C int istat = CCTK_OutputVarAs (const cGH *cctkGH, const char *variable, const char *alias);  Fortran call CCTK_OutputVarAs (istat, cctkGH, variable, alias) integer istat CCTK_POINTER cctkGH character*(*) variable character*(*) alias  Parameters istat return status cctkGH pointer to CCTK grid hierarchy variable full name of variable to output, with an optional options string in curly braces alias alias name to base the output filename on Discussion The output should take place if at all possible. If the appropriate file exists the data is appended, otherwise a new file is created. Uses alias as the name of the variable for the purpose of constructing a filename. Errors positive the number of IO methods which did output of variable 0 for success negative if no IO methods were registered ### CCTK_OutputVarAsByMethod Synopsis C int istat = CCTK_OutputVarAsByMethod (const cGH *cctkGH, const char *variable, const char *method, const char *alias);  Fortran call CCTK_OutputVarAsByMethod (istat, cctkGH, variable, method, alias) integer istat CCTK_POINTER cctkGH character*(*) variable character*(*) method character*(*) alias  Parameters istat return status cctkGH pointer to CCTK grid hierarchy variable full name of variable to output, with an optional options string in curly braces method method to use for output alias alias name to base the output filename on Discussion Output a variable variable using the method method if it is registered. Uses alias as the name of the variable for the purpose of constructing a filename. The output should take place if at all possible. If the appropriate file exists the data is appended, otherwise a new file is created. Errors 0 for success negative indicating some error (e.g. IO method is not registered) ### CCTK_OutputVarByMethod Synopsis C int istat = CCTK_OutputVarByMethod (const cGH *cctkGH, const char *variable, const char *method);  Fortran call CCTK_OutputVarByMethod (istat, cctkGH, variable, method) integer istat CCTK_POINTER cctkGH character*(*) variable character*(*) method  Parameters istat return status cctkGH pointer to CCTK grid hierarchy variable full name of variable to output, with an optional options string in curly braces method method to use for output Discussion Output a variable variable using the IO method method if it is registered. The output should take place if at all possible. if the appropriate file exists the data is appended, otherwise a new file is created. Errors 0 for success negative indicating some error (e.g. IO method is not registered) ### CCTK_ParallelInit Initialize the parallel subsystem Synopsis C int istat = CCTK_ParallelInit( cGH * cctkGH)  Parameters cctkGH pointer to CCTK grid hierarchy Discussion Initializes the parallel subsystem. ### CCTK_ParameterData Get parameter properties for given parameter/thorn pair. Synopsis C #include "cctk.h" const cParamData *paramdata = CCTK_ParameterData (const char *name, const char *thorn);  Result paramdata Pointer to parameter data structure Parameters name Parameter name thorn Thorn name (for private parameters) or implementation name (for restricted parameters) Discussion The thorn or implementation name must be the name of the place where the parameter is originally defined. It is not possible to pass the thorn or implementation name of a thorn that merely declares the parameter as used. See Also CCTK_ParameterGet [A428] Get the data pointer to and type of a parameter’s value CCTK_ParameterLevel [A430] Return the parameter checking level CCTK_ParameterQueryTimesSet [A431] Return number of times a parameter has been set CCTK_ParameterSet [A433] Sets the value of a parameter CCTK_ParameterValString [A445] Get the string representation of a parameter’s value CCTK_ParameterWalk [A448] Walk through list of parameters Errors NULL No parameter with that name was found. ### CCTK_ParameterFilename Returns the parameter filename. Synopsis C #include "cctk.h" int retval = CCTK_ParameterFilename(int len, char *filename)  Fortran call CCTK_ParameterFilename(retval, len, filename) INTEGER :: retval, len CHARACTER(*) :: filename  Result retval The length of the returned string. Parameters len The length of the incoming string filename String to contain the filename Discussion Returns the name of the parameter file given to Cactus, up to len characters in length and guaranteed to be NUL terminated. See Also CCTK_CommandLine [A74] Gets the command line arguments. ### CCTK_ParameterGet Get the data pointer to and type of a parameter’s value. Synopsis C #include "cctk.h" const void *paramval = CCTK_ParameterGet (const char *name, const char *thorn, int *type);  Result paramval Pointer to the parameter value Parameters name Parameter name thorn Thorn name (for private parameters) or implementation name (for restricted parameters) type If not NULL, a pointer to an integer which will hold the type of the parameter Discussion The thorn or implementation name must be the name of the place where the parameter is originally defined. It is not possible to pass the thorn or implementation name of a thorn that merely declares the parameter as used. See Also CCTK_ParameterData [A423] Get parameter properties for given parameter/thorn pair CCTK_ParameterLevel [A430] Return the parameter checking level CCTK_ParameterQueryTimesSet [A431] Return number of times a parameter has been set CCTK_ParameterSet [A433] Sets the value of a parameter CCTK_ParameterValString [A445] Get the string representation of a parameter’s value CCTK_ParameterWalk [A448] Walk through list of parameters Errors NULL No parameter with that name was found. ### CCTK_ParameterLevel Return the parameter checking level. Synopsis C #include "cctk.h" int level = CCTK_ParameterLevel (void);  Result level Parameter checking level now being used. See Also CCTK_ParameterData [A423] Get parameter properties for given parameter/thorn pair CCTK_ParameterGet [A428] Get the data pointer to and type of a parameter’s value CCTK_ParameterQueryTimesSet [A431] Return number of times a parameter has been set CCTK_ParameterSet [A433] Sets the value of a parameter CCTK_ParameterValString [A445] Get the string representation of a parameter’s value CCTK_ParameterWalk [A448] Walk through list of parameters ### CCTK_ParameterQueryTimesSet Return number of times a parameter has been set. Synopsis C #include "cctk.h" int nset = CCTK_ParameterQueryTimesSet (const char *name, const char *thorn);  Result nset Number of times the parameter has been set. Parameters name Parameter name thorn Thorn name (for private parameters) or implementation name (for restricted parameters) Discussion The number of times that a parameter has been set is 0 if the parameter was not set in a parameter file. The number increases when CCTK_ParameterSet is called. The thorn or implementation name must be the name of the place where the parameter is originally defined. It is not possible to pass the thorn or implementation name of a thorn that merely declares the parameter as used. See Also CCTK_ParameterData [A423] Get parameter properties for given parameter/thorn pair CCTK_ParameterGet [A428] Get the data pointer to and type of a parameter’s value CCTK_ParameterLevel [A430] Return the parameter checking level CCTK_ParameterSet [A433] Sets the value of a parameter CCTK_ParameterValString [A445] Get the string representation of a parameter’s value CCTK_ParameterWalk [A448] Walk through list of parameters Errors $-1$ No parameter with that name exists. ### CCTK_ParameterSet Sets the value of a parameter. Synopsis C #include "cctk.h" int ierr = CCTK_ParameterSet (const char *name, const char *thorn, const char *value);  Fortran call CCTK_ParameterSet (ierr, name, thorn, value) CCTK_INT ierr character*(*) name character*(*) thorn character*(*) value  Result ierr Error code Parameters name Parameter name thorn Thorn name (for private parameters) or implementation name (for restricted parameters) value The new (stringified) value for the parameter parameter Discussion The thorn or implementation name must be the name of the place where the parameter is originally defined. It is not possible to pass the thorn or implementation name of a thorn that merely declares the parameter as used. While setting a new parameter value is immediately reflected in Cactus’ database, the value of the parameter is not changed immediately in the routine that sets the new value: It is updated only the next time a routine is entered (or rather, when the DECLARE_CCTK_PARAMETERS is encountered the next time). It is therefore advisable to set the new parameter value in a routine scheduled at a time earlier to when the new value is required. See Also CCTK_ParameterData [A423] Get parameter properties for given parameter/thorn pair CCTK_ParameterLevel [A430] Return the parameter checking level CCTK_ParameterQueryTimesSet [A431] Return number of times a parameter has been set CCTK_ParameterSetNotifyRegister [A437] Registers a parameter set operation notify callback CCTK_ParameterSetNotifyUnregister [A441] Unregisters a parameter set operation notify callback CCTK_ParameterValString [A445] Get the string representation of a parameter’s value CCTK_ParameterWalk [A448] Walk through list of parameters Errors ierr $0$ success $-1$ parameter is out of range $-2$ parameter was not found $-3$ trying to steer a non-steerable parameter $-6$ not a valid integer or float $-7$ tried to set an accumulator parameter directly $-8$ tried to set an accumulator parameter directly $-9$ final value of accumulator out of range ### CCTK_ParameterSetNotifyRegister Registers a parameter set operation notify callback Synopsis C #include "cctk.h" int handle = CCTK_ParameterSetNotifyRegister (cParameterSetNotifyCallbackFn callback, void *data, const char *name, const char *thorn_regex, const char *param_regex  Fortran call CCTK_ParameterSetNotifyRegister (handle, callback, data, . name, thorn_regex, param_regex) integer handle external callback integer callback CCTK_POINTER data character*(*) name character*(*) thorn_regex character*(*) param_regex  Result 0 success -1 another callback has already been registered under the given name -2 memory allocation error -3 invalid regular expression given for thorn_regex / param_regex Parameters callback Function pointer of the notify callback to be registered data optional user-defined data pointer to associate with the notify callback name Unique name under which the notify callback is to be registered thorn_regex Optional regular expression string to match a thorn name in a full parameter name param_regex Optional regular expression string to match a parameter name in a full parameter name Discussion Declaring a parameter steerable at runtime in its param.ccl definition requires a thorn writer to add extra logic to the code which checks if a parameter value has changed, either periodically in a scheduled function, or by direct notification from the flesh’s parameter set routine CCTK_ParameterSet(). With CCTK_ParameterSetNotifyRegister() thorns can register a callback function which in turn is automatically invoked by CCTK_ParameterSet() whenever a parameter is being steered. Each callback function gets passed the triple of thorn name, parameter name, and (stringified) new parameter value (as passed to CCTK_ParameterSet()), plus an optional callback data pointer defined by the user at registration time. When a callback function is registered with CCTK_ParameterSetNotify(), the calling routine may also pass an optional regular expression string for both a thorn name and a parameter name to match against in a parameter set notification; leave them empty or pass a NULL pointer to get notified about changes of any parameter. Registered notification callbacks would be invoked by CCTK_ParameterSet() only after initial parameter setup from the parfile, and – in case of recovery – only after all parameters have been restored from the checkpoint file. The callbacks are then invoked just before the parameter is set to its new value so that they can still query its old value if necessary. See Also CCTK_ParameterSet [A433] Sets the value of a parameter CCTK_ParameterSetNotifyUnregister [A441] Unregisters a parameter set operation notify callback Examples C #include <stdio.h> #include "cctk.h" static void ParameterSetNotify (void *unused, const char *thorn, const char *parameter, const char *new_value) { printf ("parameter set notification: %s::%s is set to ’%s’\n", thorn, parameter, new_value); } void RegisterNotifyCallback (void) { /* we are interested only in this thorn’s parameters so pass the thorn name in the ’thorn_regex’ argument */ if (CCTK_ParameterSetNotifyRegister (ParameterSetNotify, NULL, CCTK_THORNSTRING, CCTK_THORNSTRING, NULL)) { CCTK_VWarn (0, __LINE__, __FILE__, CCTK_THORNSTRING, "Couldn’t register parameter set notify callback"); } }  ### CCTK_ParameterSetNotifyUnregister Unregisters a parameter set operation notify callback Synopsis C #include "cctk.h" int ierr = CCTK_ParameterSetNotifyUnregister (const char *name);  Fortran call CCTK_ParameterSetNotifyUnregister (ierr, name) integer ierr character*(*) name  Result 0 success -1 no callback was registered under the given name Parameters name Unique name under which the notify callback was registered Discussion Notify callbacks should be unregistered when not needed anymore. See Also CCTK_ParameterSet [A433] Sets the value of a parameter CCTK_ParameterSetNotifyRegister [A437] Registers a parameter set operation notify callback Examples Fortran #include "cctk.h" call CCTK_ParameterSetNotifyUnregister (CCTK_THORNSTRING)  ### CCTK_ParameterValString Get the string representation of a parameter’s value. Synopsis C #include "cctk.h" char *valstring = CCTK_ParameterValString (const char *name, const char *thorn);  Fortran subroutine CCTK_ParameterValString (nchars, name, thorn, value) integer nchars character*(*) name character*(*) thorn character*(*) value end subroutine  Result valstring Pointer to parameter value as string. The memory for this string must be released with a call to free() after it has been used. Parameters name Parameter name thorn Thorn name (for private parameters) or implementation name (for restricted parameters) nchars On exit, the number of characters in the stringified parameter value, or $-1$ if the parameter doesn’t exist value On exit, contains as many characters of the stringified parameter value as fit into the Fortran string provided. You should check for truncation by comparing nchars against the length of your Fortran string. Discussion In C, the string valstring must be freed afterwards. The thorn or implementation name must be the name of the place where the parameter is originally defined. It is not possible to pass the thorn or implementation name of a thorn that merely declares the parameter as used. Real variables are formatted according to the C "%.20g" format. See Also CCTK_ParameterData [A423] Get parameter properties for given parameter/thorn pair CCTK_ParameterGet [A428] Get the data pointer to and type of a parameter’s value CCTK_ParameterLevel [A430] Return the parameter checking level CCTK_ParameterQueryTimesSet [A431] Return number of times a parameter has been set CCTK_ParameterSet [A433] Sets the value of a parameter CCTK_ParameterWalk [A448] Walk through list of parameters Errors NULL No parameter with that name was found. ### CCTK_ParameterWalk Walk through the list of parameters. Synopsis C #include "cctk.h" % int istat = CCTK_ParameterWalk (int first, const char *origin, char **fullname, const cParamData **paramdata);  Result istat Zero for success, positive if parameter was not found, negative if initial startpoint was not set. Parameters origin Thorn name, or NULL for all thorns. fullname Address of a pointer that will point to the full parameter name. This name must be freed after use. paramdata Address of a pointer that will point to the parameter data structure. Discussion Gets parameters in order, restricted to ones from origin, or all if origin is NULL. Starts with the first parameter if first is true, otherwise gets the next one. Can be used for generating full help file, or for walking the list and checkpointing. See Also CCTK_ParameterData [A423] Get parameter properties for given parameter/thorn pair CCTK_ParameterGet [A428] Get the data pointer to and type of a parameter’s value CCTK_ParameterLevel [A430] Return the parameter checking level CCTK_ParameterQueryTimesSet [A431] Return number of times a parameter has been set CCTK_ParameterSet [A433] Sets the value of a parameter CCTK_ParameterValString [A445] Get the string representation of a parameter’s value Errors negative The initial startpoint was not set. ### CCTK_PARAMWARN Prints a warning from parameter checking, and possibly stops the code Synopsis C = CCTK_PARAMWARN( const char * message)  Fortran call CCTK_PARAMWARN( , message ) character*(*) message  Parameters message The warning message Discussion The call should be used in routines registered at the schedule point CCTK_PARAMCHECK to indicate that there is parameter error or conflict and the code should terminate. The code will terminate only after all the parameters have been checked. The macro CCTK_PARAMWARN(message) expands to a call to the underlying function CCTK_ParamWarn: CCTK_ParamWarn(CCTK_THORNSTRING, message)  So the macro automatically includes the name of the originating thorn in the info message. It is recommended that the macro CCTK_PARAMWARN is used to print a message rather than calling CCTK_ParamWarn directly. To include variables in an info message from C, you can use the routine CCTK_VParamWarn which accepts a variable argument list. To include variables from Fortran, a string must be constructed and passed in a CCTK_PARAMWARN macro. Examples C CCTK_PARAMWARN("Mass cannot be negative");  Fortran call CCTK_PARAMWARN("Inside interpolator")  See Also CCTK_VParamWarn [A622] Prints a formatted string with a variable argument list as a warning from parameter checking, and possibly stops the code ### CCTK_PointerTo Returns a pointer to a Fortran variable. Synopsis Fortran #include "cctk.h" CCTK_POINTER addr, var addr = CCTK_PointerTo(var)  Result addr the address of variable var Parameters var variable in the Fortran context from which to take the address Discussion Fortran doesn’t know the concept of pointers so problems arise when a C function is to be called which expects a pointer as one (or more) of it(s) argument(s). To obtain the pointer to a variable in Fortran, one can use CCTK_PointerTo() which takes the variable itself as a single argument and returns the pointer to it. Note that there is only a Fortran wrapper available for CCTK_PointerTo. See Also CCTK_NullPointer() Returns a C-style NULL pointer value. Examples Fortran #include "cctk.h" integer ierror, table_handle CCTK_POINTER addr, var addr = CCTK_PointerTo(var) call Util_TableCreate(table_handle, 0) call Util_TableSetPointer(ierror, table_handle, addr, "variable")  ### CCTK_PrintGroup Prints a group name from its index Synopsis C = CCTK_PrintGroup( int index)  Fortran call CCTK_PrintGroup( , index ) integer index  Parameters index The group index Discussion This routine is for debugging purposes for Fortran programmers. Examples C CCTK_PrintGroup(1)  Fortran call CCTK_PRINTGROUP(1)  ### CCTK_PrintString Prints a Cactus string Synopsis C = CCTK_PrintString( char * string)  Fortran call CCTK_PrintString( , string ) CCTK_STRING string  Parameters string The string to print Discussion This routine can be used to print Cactus string variables and parameters from Fortran. Examples C CCTK_PrintString(string_param)  Fortran call CCTK_PRINTSTRING(string_param)  ### CCTK_PrintVar Prints a variable name from its index Synopsis C = CCTK_PrintVar( int index)  Fortran call CCTK_PrintVar( , index ) integer index  Parameters index The variable index Discussion This routine is for debugging purposes for Fortran programmers. Examples C CCTK_PrintVar(1)  Fortran call CCTK_PRINTVAR(1)  ### CCTK_QueryGroupStorage Query storage for a group given by its group name Synopsis C int istat = CCTK_QueryGroupStorage( const cGH * cctkGH, const char * groupname)  Fortran call CCTK_QueryGroupStorage(istat , cctkGH, groupname ) integer istat CCTK_POINTER cctkGH character*(*) groupname  Parameters cctkGH pointer to CCTK grid hierarchy groupname the group to query, given by its full name istat the return code Discussion This routine queries whether the variables in a group have storage assigned. If so it returns true (a positive value), otherwise false (zero). Errors negative A negative error code is returned for an invalid group name. ### CCTK_QueryGroupStorageB Synopsis C int storage = CCTK_QueryGroupStorageB( const cGH * cctkGH, int groupindex, const char * groupname)  Parameters cctkGH pointer to CCTK grid hierarchy groupindex the group to query, given by its index groupname the group to query, given by its full name istat the return code Discussion This routine queries whether the variables in a group have storage assigned. If so it returns true (a positive value), otherwise false (zero). The group can be specified either through the group index groupindex, or through the group name groupname. The groupname takes precedence; only if it is passed as NULL, the group index is used. Errors negative A negative error code is returned for an invalid group name. ### CCTK_QueryGroupStorageI Query storage for a group given by its group index Synopsis C int istat = CCTK_QueryGroupStorageI( const cGH * cctkGH, int groupindex)  Fortran call CCTK_QueryGroupStorageI(istat , cctkGH, groupindex ) integer istat cctkGH integer groupindex  Parameters cctkGH pointer to CCTK grid hierarchy groupindex the group to query, given by its index istat the return code Discussion This routine queries whether the variables in a group have storage assigned. If so it returns true (a positive value), otherwise false (zero). Errors negative A negative error code is returned for an invalid group name. ### CCTK_ReduceArraysGlobally Performs global reduction on a list of arrays The computation is optimized for the case of reducing a number of grid arrays at a time; in this case all the interprocessor communication can be done together. Synopsis C #include "cctk.h" int CCTK_ReduceArraysGlobally(const cGH *GH, int dest_proc, int local_reduce_handle, int param_table_handle, int N_input_arrays, const void * const input_arrays[], int input_dims, const CCTK_INT input_array_dims[], const CCTK_INT input_array_type_codes[], int M_output_values, const CCTK_INT output_value_type_codes[], void* const output_values[]);  Fortran call CCTK_ReduceArraysGlobally(status, . GH, . dest_proc, . local_reduce_handle, . param_table_handle, . N_input_arrays, . input_arrays, . input_dims, . input_array_dims, . input_array_type_codes, . M_output_values, . output_value_type_codes, . output_values) integer status CCTK_POINTER_TO_CONST GH integer dest_proc, integer local_reduce_handle integer param_table_handle integer N_input_arrays CCTK_INT input_arrays(N_input_arrays) integer input_dims CCTK_INT input_array_dims(input_dims) CCTK_INT input_array_type_codes(N_input_arrays) integer M_output_values CCTK_INT output_value_type_codes(M_output_values) CCTK_POINTER output_values(M_output_values)  Result 0 success < 0 indicates an error condition Parameters cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dest_processor The destination processor. $-1$ will distribute the result to all processors. local_reduce_handle ($\ge 0$) Handle to the local reduction operator as returned by CCTK_LocalArrayReductionHandle(). It is the caller’s responsibility to ensure that the specified reducer supports any optional parameter-table entries that CCTK_ReduceGridArrays() passes to it. Each thorn providing a CCTK_ReduceGridArrays() reducer should document what options it requires from the local reducer. param_table_handle ($\ge 0$) Handle to a key-value table containing zero or more additional parameters for the reduction operation. The table can be modified by the local and/or global reduction routine(s). Also, the global reducer will typically need to specify some options of its own for the local reducer. These will override any entries with the same keys in the param_table_handle table. The discussion of individual table entries below says if these are modified in this manner. Finally, the param_table_handle table can be used to pass back arbitrary information by the local and/or global reduction routine(s) by adding/modifying appropriate key/value pairs. N_input_arrays ($\ge 0$) The number of input arrays to be reduced. If N_input_arrays is zero, then no reduction is done; such a call may be useful for setup, reducer querying, etc. If the operand_indices parameter table entry is used to specify a nontrivial (eg 1-to-many) mapping of input arrays to output values, only the unique set of input arrays should be given here. input_arrays (Pointer to) an array of N_input_arrays local arrays specifying the input arrays for the reduction. input_dims ($\ge 0$) The number of dimensions of the input arrays input_array_dims ($\ge 0$) (Pointer to) an array of size input_dims containing the dimensions of the arrays to be reduced. input_array_type_codes ($\ge 0$) (Pointer to) an array of input_dims CCTK_VARIABLE_* type codes giving the data types of the arrays to be reduced. M_output_values ($\ge 0$) The number of output values to be returned from the reduction. If N_input_arrays == 0 then no reduction is done; such a call may be useful for setup, reducer querying, etc. Note that M_output_values may differ from N_input_arrays , eg if the operand_indices parameter table entry is used to specify a nontrivial (eg many-to-1) mapping of input arrays to output values, If such a mapping is specified, only the unique set of output values should be given here. output_value_type_codes (Pointer to) an array of M_output_values CCTK_VARIABLE_* type codes giving the data types of the output values pointed to by output_values[]. output_values (Pointer to) an array of M_output_values pointers to the (caller-supplied) output values for the reduction. If output_values[out] is NULL for some index or indices out , then that reduction is skipped. (This may be useful if the main purpose of the call is (eg) to do some query or setup computation.) These pointers may (and typically will) vary from processor to processor in a multiprocessor Cactus run. However, any given pointer must be either NULL on all processors, or non-NULL on all processors. 4 Discussion This function reduces a list of CCTK local arrays globally. This function does not perform the actual reduction, it only handles interprocessor communication. The actual reduction is performed by the local reduction implementation, that is passed arguments and parameters from the grid array reduction implementation. Note that CCTK_ReduceArraysGlobally is a collective operation, so in the multiprocessor case you must call this function in parallel on each processor, passing identical arguments. See Also CCTK_LocalArrayReductionHandle() Returns the handle of a given local array reduction operator CCTK_RegisterGridArrayReductionOperator() Registers a function as a grid array reduction operator of a certain name CCTK_GridArrayReductionOperator() The name of the grid reduction operator, or NULL if the handle is invalid CCTK_GridArrayReductionOperator() The number of grid array reduction operators registered Examples Here’s a simple example to perform grid array reduction of two grids arrays of different types. C  #include "cctk.h" #include "util_Table.h" #define N_INPUT_ARRAYS 2 #define M_OUTPUT_VALUES 2 const cGH *GH; /* input */ /* create empty parameter table */ const int param_table_handle = Util_CreateTable(UTIL_TABLE_FLAGS_CASE_INSENSITIVE); /* input arrays and output values */ const CCTK_INT input_array_variable_indices[N_INPUT_ARRAYS] = { CCTK_VarIndex("my_thorn::real_array"), /* no error checking */ CCTK_VarIndex("my_thorn::complex_array") }; /* here */ const CCTK_INT output_value_type_codes[M_OUTPUT_VALUES] = { CCTK_VARIABLE_REAL, CCTK_VARIABLE_COMPLEX }; void *const output_numbers[M_OUTPUT_values] = { (void *) output_for_real_values, (void *) output_for_complex_values }; const int status = CCTK_ReduceGridArrays(GH, 0, param_table_handle, N_INPUT_ARRAYS, input_array_variable_indices, M_OUTPUT_VALUES, output_value_type_codes, output_values); Util_TableDestroy(param_table_handle);  ### CCTK_ReduceGridArrays Performs reduction on a list of distributed grid arrays The computation is optimized for the case of reducing a number of grid arrays at a time; in this case all the interprocessor communication can be done together. Synopsis C #include "cctk.h" int status = CCTK_ReduceGridArrays(const cGH *GH, int dest_processor, int local_reduce_handle, int param_table_handle, int N_input_arrays, const CCTK_INT input_array_variable_indices[], int M_output_values, const CCTK_INT output_value_type_codes[], void* const output_values[]);  Fortran call CCTK_ReduceGridArrays(status, . GH, . dest_processor, . local_reduce_handle, . param_table_handle, . N_input_arrays, . input_array_variable_indices, . M_output_values, . output_value_type_codes, . output_values) integer status CCTK_POINTER_TO_CONST GH integer dest_processor integer local_reduce_handle integer param_table_handle integer N_input_arrays CCTK_INT input_array_variable_indices(N_input_arrays) integer M_output_values CCTK_INT output_value_type_codes(M_output_values) CCTK_POINTER output_values(M_output_values)  Result 0 success < 0 indicates an error condition Parameters cctkGH ($\ne$ NULL) Pointer to a valid Cactus grid hierarchy. dest_processor The destination processor. $-1$ will distribute the result to all processors. local_reduce_handle ($\ge 0$) Handle to the local reduction operator as returned by CCTK_LocalArrayReductionHandle(). It is the caller’s responsibility to ensure that the specified reducer supports any optional parameter-table entries that CCTK_ReduceGridArrays() passes to it. Each thorn providing a CCTK_ReduceGridArrays() reducer should document what options it requires from the local reducer. param_table_handle ($\ge 0$) Handle to a key-value table containing zero or more additional parameters for the reduction operation. The table can be modified by the local and/or global reduction routine(s). Also, the global reducer will typically need to specify some options of its own for the local reducer. These will override any entries with the same keys in the param_table_handle table. The discussion of individual table entries below says if these are modified in this manner. Finally, the param_table_handle table can be used to pass back arbitrary information by the local and/or global reduction routine(s) by adding/modifying appropriate key/value pairs. N_input_arrays ($\ge 0$) The number of input arrays to be reduced. If N_input_arrays is zero, then no reduction is done; such a call may be useful for setup, reducer querying, etc. If the operand_indices parameter table entry is used to specify a nontrivial (eg 1-to-many) mapping of input arrays to output values, only the unique set of input arrays should be given here. input_array_variable_indices (Pointer to) an array of N_input_arrays Cactus variable indices (as returned by CCTK_VarIndex() ) specifying the input grid arrays for the reduction. If input_array_variable_indices[in] == -1 for some index or indices in , then that reduction is skipped. (This may be useful if the main purpose of the call is (eg) to do some query or setup computation.) M_output_values ($\ge 0$) The number of output values to be returned from the reduction. If N_input_arrays == 0 then no reduction is done; such a call may be useful for setup, reducer querying, etc. Note that M_output_values may differ from N_input_arrays , eg if the operand_indices parameter table entry is used to specify a nontrivial (eg many-to-1) mapping of input arrays to output values, If such a mapping is specified, only the unique set of output values should be given here. output_value_type_codes (Pointer to) an array of M_output_values CCTK_VARIABLE_* type codes giving the data types of the output values pointed to by output_values[]. output_values (Pointer to) an array of M_output_values pointers to the (caller-supplied) output values for the reduction. If output_values[out] is NULL for some index or indices out , then that reduction is skipped. (This may be useful if the main purpose of the call is (eg) to do some query or setup computation.) These pointers may (and typically will) vary from processor to processor in a multiprocessor Cactus run. However, any given pointer must be either NULL on all processors, or non-NULL on all processors. Discussion This function reduces a list of CCTK grid arrays (in a multiprocessor run these are generally distributed over processors). This function does not perform the actual reduction, it only handles interprocessor communication. The actual reduction is performed by the local reduction implementation, that is passed arguments and parameters from the grid array reduction implementation. Note that CCTK_ReduceGridArrays is a collective operation, so in the multiprocessor case you must call this function in parallel on each processor, passing identical arguments. See Also CCTK_LocalArrayReductionHandle() Returns the handle of a given local array reduction operator CCTK_RegisterGridArrayReductionOperator() Registers a function as a grid array reduction operator of a certain name CCTK_GridArrayReductionOperator() The name of the grid reduction operator, or NULL if the handle is invalid CCTK_GridArrayReductionOperator() The number of grid array reduction operators registered Examples Here’s a simple example to perform grid array reduction of two grids arrays of different types. C  #include "cctk.h" #include "util_Table.h" #define N_INPUT_ARRAYS 2 #define M_OUTPUT_VALUES 2 const cGH *GH; /* input */ /* create empty parameter table */ const int param_table_handle = Util_CreateTable(UTIL_TABLE_FLAGS_CASE_INSENSITIVE); /* input arrays and output values */ const CCTK_INT input_array_variable_indices[N_INPUT_ARRAYS] = { CCTK_VarIndex("my_thorn::real_array"), /* no error checking */ CCTK_VarIndex("my_thorn::complex_array") }; /* here */ const CCTK_INT output_value_type_codes[M_OUTPUT_VALUES] = { CCTK_VARIABLE_REAL, CCTK_VARIABLE_COMPLEX }; void *const output_numbers[M_OUTPUT_values] = { (void *) output_for_real_values, (void *) output_for_complex_values }; const int status = CCTK_ReduceGridArrays(GH, 0, param_table_handle, N_INPUT_ARRAYS, input_array_variable_indices, M_OUTPUT_VALUES, output_value_type_codes, output_values); Util_TableDestroy(param_table_handle);  ### CCTK_ReduceLocalArrays Performs reduction on a list of local grid arrays Synopsis C #include "cctk.h" int status = CCTK_ReduceLocalArrays(int N_dims, int operator_handle, int param_table_handle, int N_input_arrays, const CCTK_INT input_array_dims[], const CCTK_INT input_array_type_codes[], const void *const input_arrays[], int M_output_numbers, const CCTK_INT output_number_type_codes[], void *const output_values[]);  Fortran call CCTK_ReduceLocalArrays(status, . N_dims, operator_handle, . param_table_handle, N_input_arrays, . input_array_dims, . input_array_type_codes, . input_arrays, . M_output_numbers, . output_number_type_codes, . output_values) integer status integer N_dims integer operator_handle integer param_table_handle integer N_input_arrays CCTK_INT input_array_dims(N_dims) CCTK_INT input_array_type_codes(N_input_arrays) CCTK_POINTER input_arrays(N_input_arrays) integer M_output_values CCTK_INT output_value_type_codes(M_output_values) CCTK_POINTER output_values(M_output_values)  Result 0 success < 0 indicates an error condition Parameters N_dims Number of dimensions of input arrays. This is required to find proper indices for arrays in memory operator_handle Handle to the local reduction operator as returned by CCTK_LocalArrayReductionHandle(). param_table_handle Handle to a key-value table containing zero or more additional parameters for the reduction operation. The table can be modified by the local and/or global reduction routine(s). The parameter table may be used to specify non-default storage indexing for input or output arrays, and/or various options for the reduction itself. Some reducers may not implement all of these options. N_input_arrays ($\ge 0$) The number of input arrays to be reduced. If N_input_arrays is zero, then no reduction is done; such a call may be useful for setup, reducer querying, etc. If the operand_indices parameter table entry is used to specify a nontrivial (eg 1-to-many) mapping of input arrays to output values, only the unique set of input arrays should be given here. input_array_dims array of input array dimensions (common to all input arrays) and of size N_dims input_array_type_codes array of input array dimensions (common to all input arrays) and of size N_input_arrays M_output_values ($\ge 0$) The number of output values to be returned from the reduction. If N_input_arrays == 0 then no reduction is done; such a call may be useful for setup, reducer querying, etc. Note that M_output_values may differ from N_input_arrays , eg if the operand_indices parameter table entry is used to specify a nontrivial (eg many-to-1) mapping of input arrays to output values, If such a mapping is specified, only the unique set of output values should be given here. output_value_type_codes (Pointer to) an array of M_output_values CCTK_VARIABLE_* type codes giving the data types of the output values pointed to by output_values[]. output_values (Pointer to) an array of M_output_values pointers to the (caller-supplied) output values for the reduction. If output_values[out] is NULL for some index or indices out , then that reduction is skipped. (This may be useful if the main purpose of the call is (eg) to do some query or setup computation.) Discussion Sometimes one of the arrays used by the reduction isn’t contiguous in memory. So, we use several optional table entries (these should be supported by all reduction operators): For the input arrays, we use  const CCTK_INT input_array_offsets[N_input_arrays]; /* next 3 table entries are shared by all input arrays */ const CCTK_INT input_array_strides [N_dims]; const CCTK_INT input_array_min_subscripts[N_dims]; const CCTK_INT input_array_max_subscripts[N_dims];  Then for input array number a, the generic subscripting expression for the 3-D case is  data_pointer[offset + i*istride + j*jstride + k*kstride]  where  data_pointer = input_arrays[a] offset = input_array_offsets[a] (istride,jstride,kstride) = input_array_stride[]  and where (i,j,k) run from input_array_min_subscripts[] to input_array_max_subscripts[] inclusive. The defaults are offset=0, stride=determined from input_array_dims[] in the usual Fortran manner, input_array_min_subscripts[] = 0, input_array_max_subscripts[] = input_array_dims[]-1. If the stride and max subscript are both specified explicitly, then the input_array_dims[] function argument is ignored. See Also CCTK_LocalArrayReductionHandle() Returns the handle of a given local array reduction operator CCTK_RegisterLocalArrayReductionOperator() Registers a function as a reduction operator of a certain name CCTK_LocalArrayReduceOperatorImplementation() Provide the implementation which provides an local array reduction operator CCTK_LocalArrayReduceOperator() Returns the name of a registered reduction operator CCTK_NumLocalArrayReduceOperators() The number of local reduction operators registered Examples Here’s a simple example, written in Fortran 77, to do reduction of a real and a complex local array in 3-D: Fortran 77  c input arrays: integer ni, nj, nk parameter (ni=..., nj=..., nk=...) CCTK_REAL real_array (ni,nj,nk) CCTK_COMPLEX complex_array(ni,nj,nk) c output numbers: CCTK_REAL My_real (M_reduce) CCTK_COMPLEX My_complex(M_reduce) integer status, dummy CCTK_INT input_array_type_codes(2) data input_array_type_codes /CCTK_VARIABLE_REAL,$                               CCTK_VARIABLE_COMPLEX/
CCTK_INT input_array_dims(3)
CCTK_POINTER input_arrays(2)
CCTK_POINTER output_numbers(2)

input_array_dims(1) = ni
input_array_dims(2) = nj
input_array_dims(3) = nk
output_numbers(1) = Util_PointerTo(My_real)
output_numbers(2) = Util_PointerTo(My_complex)

call CCTK_ReduceLocalArrays
\$          (status,                ! return code
3,                     ! number of dimensions
operator_handle,
N_reduce,
2,                     ! number of input arrays
input_array_type_codes, input_array_dims, input_arrays,
2,                     ! number of output numbers
output_numbers_type_codes, output_numbers)

if (status .lt. 0) then
call CCTK_WARN(CCTK_WARN_ABORT, "Error return from reducer!")
end if



### CCTK_ReductionHandle

Handle for given reduction method

Synopsis

C

int handle = CCTK_ReductionHandle( const char * reduction)


Fortran

handle = CCTK_ReductionHandle(  reduction )

integer handle
character*(*) reduction


Parameters

handle handle returned for this method
name name of the reduction method required

Discussion

Reduction methods should be registered at CCTK_STARTUP. Note that integer reduction handles are used to call CCTK_Reduce to avoid problems with passing Fortran strings. Note that the name of the reduction operator is case dependent.

Examples

C

handle = CCTK_ReductionHandle("maximum");


Fortran

call CCTK_ReductionHandle(handle,"maximum")


### CCTK_RegexMatch

Perform a regular expression match of string against pattern

Synopsis

C

success = CCTK_RegexMatch( const char *string, const char *pattern,
const int nmatch, regmatch_t *pmatch)


Parameters

string String to match against
pattern Regex pattern
nmatch The size of the pmatch array
pmatch Array in which to place the matches

Result

0 pattern does not match
1 pattern matches
< 0 indicates an error condition (pattern did not compile as a regular expression)

Discussion

Perform a regular expression match of string against pattern. Also returns the specified number of matched substrings as give by regexec. This is a modified form of the example routine given in the SGI man page for regcomp.

Examples

C

#define R_BEGIN "(\$|\$$)?" #define R_VALUE "([^]):]*)" #define R_SEP ":" #define R_END "(\$|\$$)?"
#define R_MAYBE(x) "(" x ")?"

int matched;
const char pattern[] =
R_BEGIN
R_VALUE
R_MAYBE(R_SEP R_VALUE R_MAYBE(R_SEP R_VALUE))
R_END;

if( (matched = CCTK_RegexMatch(range, pattern, 8, pmatch)) > 0) {
CCTK_VInfo(CCTK_THORNSTRING, "’%s’ is a valid range specifier",
range);
} else if(!matched) {
CCTK_VInfo(CCTK_THORNSTRING, "’%s’ is not a valid range specifier",
range);
} else {
CCTK_VInfo(CCTK_THORNSTRING, "invalid pattern ’%s’", pattern);
}


### CCTK_RegisterBanner

Register a banner for a thorn

Synopsis

C

void = CCTK_RegisterBanner( const char * message)


Fortran

call CCTK_RegisterBanner(  , message )

character*(*) message


Parameters

message String which will be displayed as a banner

Discussion

The banner must be registered during CCTK_STARTUP. The banners are displayed in the order in which they are registered.

Examples

C

CCTK_RegisterBanner("My Thorn: Does Something Useful");


Fortran

call CCTK_REGISTERBANNER("*** MY THORN ***")


### CCTK_RegisterGHExtension

Register an extension to the CactusGH

Synopsis

C

int istat = CCTK_RegisterGHExtension( const char * name)


### CCTK_RegisterGHExtensionInitGH

Register a function which will initialise a given extension to the Cactus GH

Synopsis

C

int istat = CCTK_RegisterGHExtensionInitGH(  int handle, void * (*func)(cGH *))


### CCTK_RegisterGHExtensionScheduleTraverseGH

Register a GH extension schedule traversal routine

Synopsis

C

int istat = CCTK_RegisterGHExtensionScheduleTraverseGH( int handle, int (*func)(cGH *,const char *))


### CCTK_RegisterGHExtensionSetupGH

Register a function which will set up a given extension to the Cactus GH

Synopsis

C

int istat = CCTK_RegisterGHExtensionSetupGH(  int handle, void * (*func)(tFleshConfig *, int, cGH *))


### CCTK_RegisterGridArrayReductionOperator

Registers a function as a grid array reduction operator of a certain name

Synopsis

C

#include "cctk.h"

int status = CCTK_RegisterGridArrayReductionOperator(
cGridArrayReduceOperator operator)


Result

0 success
< 0 indicates an error condition

Parameters

operator The function to register as a global reduction function.

Discussion

This function simply registers a function as the grid array reduction. Currently we support a single function as a global reduction function (this can be modified to accomodate more functions if need be).

CCTK_ReduceGridArrays() Performs reduction on a list of distributed grid arrays

CCTK_GridArrayReductionOperator() The name of the grid reduction operator, or NULL if none is registered

CCTK_NumGridArrayReductionOperators() The number of grid array reduction operators registered

### CCTK_RegisterIOMethod

Register a new I/O method

Synopsis

C

int handle = CCTK_RegisterIOMethod( const char * name)


Fortran

handle = CCTK_RegisterIOMethod( name )

integer handle
name


Parameters

handle handle returned by registration
name name of the I/O method

Discussion

IO methods should be registered at CCTK_STARTUP.

### CCTK_RegisterIOMethodOutputGH

Register a routine for an I/O method which will be called from CCTK_OutputGH.

Synopsis

C

int istat = CCTK_RegisterIOMethodOutputGH(  int handle, int (* func)(const cGH *))


### CCTK_RegisterIOMethodOutputVarAs

Register a routine for an I/O method which will provide aliased variable output

Synopsis

C

int istat = CCTK_RegisterIOMethodOutputVarAs(  int handle, int (* func)(const cGH *,const char*, const char *))


### CCTK_RegisterIOMethodTimeToOutput

Register a routine for an I/O method which will decide if it is time for the method to output.

Synopsis

C

int istat = CCTK_RegisterIOMethodTimeToOutput(  int handle, int (* func)(const cGH *,int))


### CCTK_RegisterIOMethodTriggerOutput

Register a routine for an I/O method which will handle trigger output

Synopsis

C

int istat = CCTK_RegisterIOMethodTriggerOutput(  int handle, int (* func)(const cGH *,int))


### CCTK_RegisterLocalArrayReductionOperator

Registers a function as a reduction operator of a certain name

Synopsis

C

#include "cctk.h"

int handle = CCTK_RegisterLocalArrayReductionOperator(
cLocalArrayReduceOperator operator, const char *name);


Result

handle The handle corresponding to the registered local reduction operator, -1 if an error occured.

Parameters

operator The function to be registered as a local reduction operator
name The name under which the operator is registered as a local reduction operator

Discussion

This function registers a local array reduction operator. It registers an operator under a name with the flesh and returns its assigned handle. If another reduction operator exists with the same name, an error is returned.

CCTK_ReduceLocalArrays() Reduces a list of local arrays (new local array reduction API)

CCTK_LocalArrayReductionHandle() Returns the handle of a given local array reduction operator

CCTK_LocalArrayReduceOperatorImplementation() Provide the implementation which provides an local array reduction operator

CCTK_LocalArrayReduceOperator() Returns the name of a registered reduction operator

CCTK_NumLocalArrayReduceOperators() The number of local reduction operators registered

### CCTK_RegisterReduceArraysGloballyOperator

Registers a function as a reduction operator of a certain name

Synopsis

C

#include "cctk.h"

int handle = CCTK_RegisterReduceArraysGloballyOperator(
cReduceArraysGloballyOperator operator, const char *name);


Result

handle The handle corresponding to the registered global array reduction operator, -1 if an error occured.

Parameters

operator The function to be registered as a global array reduction operator
name The name under which the operator is registered as a global array reduction operator

Discussion

This function registers a global array reduction operator. It registers an operator under a name with the flesh and returns its assigned handle. If another reduction operator exists with the same name, an error is returned.

CCTK_ReduceArraysGlobally() Reduces a list of local arrays globally

### CCTK_RegisterReductionOperator

Synopsis

C

CCTK_RegisterReductionOperator()


### CCTK_RunTime

Synopsis

C

int CCTK_RunTime()


Seconds since startup.

Result

seconds The number of seconds since the run started.

### CCTK_SchedulePrintTimes

Output the timing results for a certain schedule item to stdout

Synopsis

C

#include "cctk.h"
int status = CCTK_SchedulePrintTimes(const char *where)


Result

Return code of DoScheduleTraverse, or 0 Success.

Parameters

where Name of schedule item, or NULL to print the whole schedule

Discussion

Output the timing results for a certain schedule item to stdout. The schedule item is traversed recursively if it is a schedule group or a schedule bin.

This routine is used to produce the timing output when the parameter Cactus::cctk_timer_output is set to yes.

CCTK_SchedulePrintTimesToFile Output the timing results for a certain schedule item to a file

Examples

C
Output the timer results for the Analysis bin:

#include "cctk.h"
int status = CCTK_SchedulePrintTimes("CCTK_ANALYSIS")


### CCTK_SchedulePrintTimesToFile

Output the timing results for a certain schedule item to a file

Synopsis

C

#include "cctk.h"
int status = CCTK_SchedulePrintTimesToFile(const char *where, FILE *file)


Result

Return code of DoScheduleTraverse, or 0 Success.

Parameters

where Name of schedule item, or NULL to print the whole schedule
file File to which the results are output; the file must be open for writing

Discussion

Output the timing results for a certain schedule item to a file. The schedule item is traversed recursively if it is a schedule group or a schedule bin.

Note that each processor will output its results. You should either call this routine on only a single processor, or you should pass different files on different processors.

CCTK_SchedulePrintTimes Output the timing results for a certain schedule item to stdout

Examples

C
Output the timer results of processor 3 for the Analysis bin to a file:

#include <stdio.h>
#include "cctk.h"
if (CCTK_MyProc(cctkGH)==3)
{
FILE *file = fopen("timing-results.txt", "a");
int status = CCTK_SchedulePrintTimesToFile("CCTK_ANALYSIS", file)
fclose(file);
}


### CCTK_ScheduleQueryCurrentFunction

Return the cFunctionData of the function currently executing via CCTK_CallFunction.

Synopsis

C

#include "cctk.h"
const cFunctionData *CCTK_ScheduleQueryCurrentFunction(const cGH *GH)


Result

Data of last call to CCTK_CallFunction, or NULL if not within a scheduled function.

Parameters

cctkGH Pointer to a Cactus grid hierarchy.

Discussion

Returns a data structure containing the thorn and routine name of the currently executing function as well as the Cactus schedule bin or schedule group name. If no function is currently executing, returns NULL. This is intended to be used by thorns providing callable functions to identify their caller when reporting errors.

CCTK_CallFunction Calls a function depending upon the data passed in the the fdata structure.

Examples

C
Output the name of the currently scheduled function:

#include <stdio.h>
#include "cctk.h"
const cFunctionData *fdata = CCTK_ScheduleQueryCurrentFunction(cctkGH);
printf("scheduled function: %s::%s AT %s\n",
fdata->thorn, fdata->routine, fdata->where);


### CCTK_ScheduleTraverse

Traverses a schedule point, and its entry and exit points if necessary.

Synopsis

C

#include "cctk.h"
typedef int (*CallFunction_t)(void *func, cFunctionData *attributes,
void *data);
int CCTK_ScheduleTraverse(const char *where, void *data,
CallFunction_t CallFunction);


Result

0 success
1 memory failure
3 unknown error

Parameters

where Schedule point
data user data passed alongto CallFunction as its last argument
CallFunction callback function with the same signature as CCTK_CallFunction. Pass NULL to use the default.

Discussion

This functions is intended to be used by driver thorns to iterate through the schedule and act on the scheduled functions. Using it in user code can lead to recursive function call warnings.

CCTK_CallFunction Calls a function depending upon the data passed in the the fdata structure.

Examples

C
Output the names of the function scheduled in MoL_PostStep:

#include <stdio.h>
#include "cctk.h"
int CallFunction(void *fun, cFunctionData *fdata, void *data) {
int *count = data;
*count += 1;
printf("scheduled function: %s::%s AT %s\n",
fdata->thorn, fdata->routine, fdata->where);
return 1; // no need to SYNC
}

int count = 0;
int ierr = CCTK_ScheduleTraverse("MoL_PostStep", CallFunction, &count);
printf("There were %d functions scheduled\n", count);


### CCTK_SetupGH

Setup a new GH

Synopsis

C

cGH * cctkGH = CCTK_SetupGH( tFleshConfig config, int convlevel)


### CCTK_SyncGroup

Synchronise the ghostzones for a group of grid variables (identified by the group name)

Synopsis

C

#include "cctk.h"
int status = CCTK_SyncGroup(const cGH* GH, const char* group_name)


Fortran

#include "cctk.h"
integer status
CCTK_POINTER GH
character*(*) group_name
call CCTK_SyncGroup(status, GH, group_name)


Result

0 Success.

Parameters

GH A pointer to a Cactus grid hierarchy.
group_name The full name (Implementation::group or Thorn::group) of the group to be synchronized.

Discussion

Only those grid variables which have communication enabled will be synchronised. This is usually equivalent to the variables which have storage assigned, unless communication has been explicitly turned off with a call to CCTK_DisableGroupComm.

Note that an alternative to calling CCTK_SyncGroup explicitly from within a thorn, is to use the SYNC keyword in a thorns schedule.ccl file to indicate which groups of variables need to be synchronised on exit from the routine. This latter method is the preferred method from synchronising variables.

Note that CCTK_SyncGroup is a collective operation, so in the multiprocessor case you must call this function in parallel on each processor, passing the same group_name argument.

CCTK_SyncGroupI [A539] Synchronise the ghostzones for a group of grid variables (identified by the group index)
CCTK_SyncGroupsI [A544] Synchronise the ghostzones for a list of groups of grid variables (identified by their group indices)

Errors

-1 group_name was invalid.
-2 The driver returned an error on syncing the group.

Examples

C

#include "cctk.h"
#include "cctk_Arguments.h"

/* this function synchronizes the ADM metric */
{
DECLARE_CCTK_ARGUMENTS      /* defines "magic variable" cctkGH */

const int status = CCTK_SyncGroup(cctkGH, "ADMBase::metric");
if (status < 0)
CCTK_VWarn(CCTK_WARN_ABORT, __LINE__, __FILE__, CCTK_THORNSTRING,
"        failed to synchronize ADM metric!\n"
"        (CCTK_SyncGroup() returned error code %d)\n"
,
status);                                 /*NOTREACHED*/
}


### CCTK_SyncGroupI

Synchronise the ghostzones for a group of grid variables (identified by the group index)

Synopsis

C

#include "cctk.h"
int status = CCTK_SyncGroupI(const cGH* GH, int group_index)


Fortran

#include "cctk.h"
integer status
CCTK_POINTER GH
integer group_index
call CCTK_SyncGroupI(status, GH, group_index)


Result

0 Success.

Parameters

GH A pointer to a Cactus grid hierarchy.
group_index The group index of the group to be synchronized.

Discussion

Only those grid variables which have communication enabled will be synchronised. This is usually equivalent to the variables which have storage assigned, unless communication has been explicitly turned off with a call to CCTK_DisableGroupComm.

Note that an alternative to calling CCTK_SyncGroupI explicitly from within a thorn, is to use the SYNC keyword in a thorns schedule.ccl file to indicate which groups of variables need to be synchronised on exit from the routine. This latter method is the preferred method from synchronising variables.

Note that CCTK_SyncGroupI is a collective operation, so in the multiprocessor case you must call this function in parallel on each processor, passing the same group_name argument.

CCTK_SyncGroup [A535] Synchronise the ghostzones for a group of grid variables (identified by the group name)
CCTK_SyncGroupsI [A544] Synchronise the ghostzones for a list of groups of grid variables (identified by their group indices)
CCTK_GroupIndex [A236] Gets the group index for a given group name.
CCTK_GroupIndexFromVar [A240] Gets the group index for a given variable name.

Errors

-1 group_name was invalid.
-2 The driver returned an error on syncing the group.

Examples

C

#include "cctk.h"
#include "cctk_Arguments.h"

/* this function synchronizes the ADM metric */
{
DECLARE_CCTK_ARGUMENTS      /* defines "magic variable" cctkGH */

int group_index, status;

if (group_index < 0)
CCTK_VWarn(CCTK_WARN_ABORT, __LINE__, __FILE__, CCTK_THORNSTRING,
"        couldn’t get group index for ADM metric!\n"
"        (CCTK_GroupIndex() returned error code %d)\n"
,
group_index);                            /*NOTREACHED*/

status = CCTK_SyncGroupI(cctkGH, group_index);
if (status < 0)
CCTK_VWarn(CCTK_WARN_ABORT, __LINE__, __FILE__, CCTK_THORNSTRING,
"        failed to synchronize ADM metric!\n"
"        (CCTK_SyncGroupI() returned error code %d)\n"
,
status);                                 /*NOTREACHED*/
}


### CCTK_SyncGroupsI

Synchronise the ghostzones for a list of groups of grid variables (identified by their group indices)

Synopsis

C

#include "cctk.h"
int status = CCTK_SyncGroupsI(const cGH* GH, int num_groups, const int *groups)


Fortran

#include "cctk.h"
integer status
CCTK_POINTER GH
integer num_groups
integer groups(num_groups)
call CCTK_SyncGroupsI(status, GH, num_groups, groups)


Result

0 Returns the number of groups that have been synchronised.

Parameters

GH A pointer to a Cactus grid hierarchy.
num_groups The number of groups to be synchronised.
groups The group indices of the groups to be synchronized.

Discussion

Only those grid variables which have communication enabled will be synchronised. This is usually equivalent to the variables which have storage assigned, unless communication has been explicitly turned off with a call to CCTK_DisableGroupComm.

Note that an alternative to calling CCTK_SyncGroupsI explicitly from within a thorn, is to use the SYNC keyword in a thorns schedule.ccl file to indicate which groups of variables need to be synchronised on exit from the routine. This latter method is the preferred method from synchronising variables.

Note that CCTK_SyncGroupsI is a collective operation, so in the multiprocessor case you must call this function in parallel on each processor, passing the same number of groups in the same order.

CCTK_SyncGroup [A535] Synchronise the ghostzones for a single group of grid variables (identified by the group name)
CCTK_SyncGroupI [A539] Synchronise the ghostzones for a single group of grid variables (identified by the group index)
CCTK_GroupIndex [A236] Gets the group index for a given group name.
CCTK_GroupIndexFromVar [A240] Gets the group index for a given variable name.

Examples

C

#include "cctk.h"
#include "cctk_Arguments.h"

/* this function synchronizes the ADM metric and lapse */
{
DECLARE_CCTK_ARGUMENTS      /* defines "magic variable" cctkGH */

int group_indices[2], status;

if (group_indices[0] < 0)
CCTK_VWarn(CCTK_WARN_ABORT, __LINE__, __FILE__, CCTK_THORNSTRING,
"        couldn’t get group index for ADM metric!\n"
"        (CCTK_GroupIndex() returned error code %d)\n"
,
group_indices[0]);                            /*NOTREACHED*/
if (group_indices[1] < 0)
CCTK_VWarn(CCTK_WARN_ABORT, __LINE__, __FILE__, CCTK_THORNSTRING,
"        couldn’t get group index for ADM lapse!\n"
"        (CCTK_GroupIndex() returned error code %d)\n"
,
group_indices[1]);                            /*NOTREACHED*/

status = CCTK_SyncGroupsI(cctkGH, 2, group_indices);
if (status != 2)
CCTK_VWarn(CCTK_WARN_ABORT, __LINE__, __FILE__, CCTK_THORNSTRING,
"        failed to synchronize ADM metric and lapse!\n"
"        (CCTK_SyncGroupsI() returned error code %d)\n"
,
status);                                 /*NOTREACHED*/
}


### CCTK_TerminateNext

Causes a Cactus simulation to terminate after present iteration finishes

Synopsis

C

#include "cctk.h"

void CCTK_TerminateNext (const cGH *cctkGH)


Fortran

#include "cctk.h"

call CCTK_TerminateNext (cctkGH)
CCTK_POINTER_TO_CONST    cctkGH


Parameters

cctkGH Pointer to a Cactus grid hierarchy.

Discussion

This function triggers unconditional termination of Cactus after the present iteration. It bypasses all other termination conditions specified in the Cactus::terminate keyword parameter.

At this time, the cctkGH parameter does nothing.

CCTK_TerminationReached [A551] Returns true if CCTK_TerminateNext has been called.

### CCTK_TerminationReached

Returns true if CCTK_TerminateNext has been called.

Synopsis

C

#include "cctk.h"

void CCTK_TerminationReached (const cGH *cctkGH)


Fortran

#include "cctk.h"

call CCTK_TerminationReached (cctkGH)
CCTK_POINTER_TO_CONST    cctkGH


Parameters

cctkGH Pointer to a Cactus grid hierarchy.

Discussion

Returns true if Cactus has been requested to terminate after the present iteration by the CCTK_TerminateNext function.

At this time, the cctkGH parameter does nothing.

CCTK_TerminateNext [A549] Causes a Cactus simulation to terminate after the present iteration.

### CCTK_ThornImplementation

Returns the implementation provided by the thorn.

Synopsis

C

#include "cctk.h"

const char *imp = CCTK_ThornImplementationThorn(const char *name);


Result

imp Name of the implementation or NULL

Parameters

name Name of the thorn

CCTK_ActivatingThorn [A32] Finds the thorn which activated a particular implementation
CCTK_CompiledImplementation [A79] Return the name of the compiled implementation with given index
CCTK_CompiledThorn [A81] Return the name of the compiled thorn with given index
CCTK_ImplementationRequires [A302] Return the ancestors for an implementation
CCTK_ImplementationThorn [A304] Returns the name of one thorn providing an implementation.
CCTK_ImpThornList [A306] Return the thorns for an implementation
CCTK_IsImplementationActive [A346] Reports whether an implementation was activated in a parameter file
CCTK_IsImplementationCompiled [A348] Reports whether an implementation was compiled into a configuration
CCTK_IsThornActive [A350] Reports whether a thorn was activated in a parameter file
CCTK_IsThornCompiled [A353] Reports whether a thorn was compiled into a configuration
CCTK_NumCompiledImplementations [A378] Return the number of implementations compiled in
CCTK_NumCompiledThorns [A380] Return the number of thorns compiled in

Errors

NULL Error.

### CCTK_Timer

Fills a cTimerData structure with timer clock info, for the timer specified by name.

Synopsis

C

int err = CCTK_Timer(name,info)


Parameters

const char * name Timer name

cTimerData * info Timer clock info pointer

Errors

A negative return value indicates an error.

### CCTK_TimerCreate

Creates a timer with a given name, returns an index to the timer.

Synopsis

C

int index = CCTK_TimerCreate(name)


Parameters

const char * name timer name

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerCreateData

Allocates the cTimerData structure, which is used to store timer clock info.

Synopsis

C

cTimerData * info = CCTK_TimerCreateData()


Errors

NULL A null return value indicates an error.

### CCTK_TimerCreateI

Creates an unnamed timer, returns an index to the timer.

Synopsis

C

int index = CCTK_TimerCreate()


Errors

< 0 A negative return value indicates an error.

### CCTK_TimerDestroy

Reclaims resources used by the given timer, specified by name.

Synopsis

C

int err = CCTK_TimerDestroy(name)


Parameters

const char * name timer name

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerDestroyData

Releases resources from the cTimerData structure, created by CCTK_TimerCreateData.

Synopsis

C

int err = CCTK_TimerDestroyData(info)


Parameters

cTimerData * info Timer clock info pointer

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerDestroyI

Reclaims resources used by the given timer, specified by index.

Synopsis

C

int err = CCTK_TimerDestroyI(index)


Parameters

int index timer index

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerI

Fills a cTimerData structure with timer clock info, for the timer specified by index.

Synopsis

C

int err = CCTK_TimerI(index,info)


Parameters

int index Timer index

cTimerData * info Timer clock info pointer

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerReset

Gets values from all the clocks in the given timer, specified by name.

Synopsis

C

int err = CCTK_TimerReset(name)


Parameters

const char * name timer name

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerResetI

Gets values from all the clocks in the given timer, specified by index.

Synopsis

C

int err = CCTK_TimerResetI(index)


Parameters

int index timer index

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerStart

Initialises all the clocks in the given timer, specified by name.

Synopsis

C

int err = CCTK_TimerStart(name)


Parameters

const char * name timer name

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerStartI

Initialises all the clocks in the given timer, specified by index.

Synopsis

C

int err = CCTK_TimerStartI(index)


Parameters

int index timer index

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerStop

Gets values from all the clocks in the given timer, specified by name.

Synopsis

C

int err = CCTK_TimerStop(name)


Parameters

int name timer name

Discussion

Call this before getting the values from any of the timer’s clocks.

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerStopI

Gets values from all the clocks in the given timer, specified by index.

Synopsis

C

int err = CCTK_TimerStopI(index)


Parameters

int index timer index

Discussion

Call this before getting the values from any of the timer’s clocks.

Errors

< 0 A negative return value indicates an error.

### CCTK_TimerIsRunning

Checks if a Cactus timer is running, given its name. Returns 0 of not (or in case of errors) and 1 if the timer is running.

Synopsis

C

int err = CCTK_TimerIsRunning(name)


Fortran

call CCTK_TimerIsRunning(isrunning, name)
integer isrunning
character*(*) name


Parameters

char* name timer name

Discussion

Errors are treated as non-running timers: 0 is returned.

### CCTK_TimerIsRunningI

Checks if a Cactus timer is running, given its handle. Returns 0 of not (or in case of errors) and 1 if the timer is running.

Synopsis

C

int err = CCTK_TimerIsRunningI(index)


Fortran

call CCTK_TimerIsRunningI(isrunning , index )
integer isrunning
integer index


Parameters

int index timer index

Discussion

Errors are treated as non-running timers: 0 is returned.

### CCTK_TraverseString

Traverse through all variables and/or groups whose names appear in the given string, and call the callback routine with those indices and an optional option string appended to the variable/group name enclosed in square braces. The special keyword ”all” in the string can be used to indicate that the callback should be called for all variables/groups.

Synopsis

C

int err = CCTK_TraverseString(traverse_string, callback, callback_arg,
selection)


Parameters

const char * traverse_string List of variable and/or group names
void (*callback) (int idx, const char *optstring, void *callback_arg) Routine to call for every variable and/or group found. idx is the Cactus variable index, optstring is the optional ‘{}’ enclosed option string after the variable name, and callback_arg is the arbitrary argument passed to CCTK_TraverseString.
void *callback_arg An arbitrary argument which gets passed to the callback routine
int selection Decides whether group and/or variable names are accepted in the string. Possible values are: CCTK_VAR, CCTK_GROUP or CCTK_GROUP_OR_VAR.

Discussion

Use this to loop over a list of variables passed in by the user.

Result

number of variables positive for the number of traversed variables

Errors

-1 no callback routine was given
-2 option string is not associated with a group or variable
-3 unterminated option string
-4 garbage found at end of option string
-5 invalid token in traversed string found

### CCTK_VarDataPtr

Returns the data pointer for a grid variable

Synopsis

C

void * ptr = CCTK_VarDataPtr( const cGH * cctkGH, int timelevel, char * name)


Fortran

call CCTK_VarDataPtr(ptr, cctkGH, timelevel, varname)
CCTK_POINTER vardataptr
CCTK_POINTER_TO_CONST cctkGH
integer timelevel
character*(*) varname


Parameters

ptr a void pointer to the grid variable data
cctkGH pointer to CCTK grid hierarchy
timelevel The timelevel of the grid variable
name The full name of the variable

Discussion

The variable name should be in the form <implementation>::<variable>.

Examples

C

myVar = (CCTK_REAL *)(CCTK_VarDataPtr(GH,0,"imp::realvar"))


Fortran

CCTK_REAL, dimension(cctk_ash(1),cctk_ash(2),cctk_ash(3)) :: var
CCTK_POINTER myVar
pointer (myVar, var)
call CCTK_VarDataPtr(myVar,GH,0,"imp::realvar")


### CCTK_VarDataPtrB

Returns the data pointer for a grid variable from the variable index or the variable name

Synopsis

C

void * ptr = CCTK_VarDataPtrB( const cGH * cctkGH, int timelevel, int index, char * name)


Parameters

ptr a void pointer to the grid variable data
cctkGH pointer to CCTK grid hierarchy
timelevel The timelevel of the grid variable
index The index of the variable
name The full name of the variable

Discussion

If the name is NULL the index will be used, if the index is negative the name will be used.

Examples

C

myVar = (CCTK_REAL *)(CCTK_VarDataPtrB(GH,0,CCTK_VarIndex("imp::realvar"),NULL));


### CCTK_VarDataPtrI

Returns the data pointer for a grid variable from the variable index

Synopsis

C

void * ptr = CCTK_VarDataPtrI( const cGH * cctkGH, int timelevel, int index)


Fortran

call CCTK_VarDataPtrI(ptr, cctkGH, timelevel, index)
CCTK_POINTER vardataptr
CCTK_POINTER_TO_CONST cctkGH
integer timelevel
integer index


Parameters

cctkGH pointer to CCTK grid hierarchy
timelevel The timelevel of the grid variable
index The index of the variable

Examples

C

myVar = (CCTK_REAL *)(CCTK_VarDataPtr(GH,0,CCTK_VarIndex("imp::realvar")));


Fortran

CCTK_REAL, dimension(cctk_ash(1),cctk_ash(2),cctk_ash(3)) :: var
CCTK_POINTER myVar
pointer (myVar, var)
call CCTK_VarDataPtr(myVar,GH,0,CCTK_VarIndex("imp::realvar"))


### CCTK_VarIndex

Get the index for a variable.

Synopsis

C

#include "cctk.h"
int index = CCTK_VarIndex(const char *varname);


Fortran

call CCTK_VarIndex(index, varname)
integer index
character*(*) varname


Parameters

varname The name of the variable.

Discussion

The variable name should be the given in its fully qualified form, that is <implementation>::<variable> for a public or protected variable, and <thornname>::<variable> for a private variable. For vector variables, the zero-based component index should be included in square brackets after the variable name.

Errors

-1 no variable of this name exists
-2 failed to catch error code from Util_SplitString
-3 given full name is in wrong format
-4 memory allocation failed

Examples

C

index = CCTK_VarIndex("evolve::phi");
index = CCTK_VarIndex("evolve::vect[0]");


Fortran

call CCTK_VarIndex(index,"evolve::phi")
call CCTK_VarIndex(index,"evolve::vect[0]")


### CCTK_VarName

Given a variable index, returns the variable name

Synopsis

C

const char * name = CCTK_VarName( int index)


Fortran

#include "cctk.h"

subroutine CCTK_VarName(nchars, index, fullname)
integer       nchars
integer       index
character*(*) name
end subroutine CCTK_VarName


Parameters

name The variable name
index The variable index

Discussion

The pointer returned is part of a structure managed by Cactus and so must not be freed after use.

Examples

C

index = CCTK_VarIndex("evolve::phi");
name = CCTK_VarName(index);


### CCTK_VarTypeI

Provides variable type index from the variable index

Synopsis

C

int type = CCTK_VarTypeI( int index)


Fortran

call CCTK_VarTypeI(type , index )

integer type
integer index


Parameters

type The variable type index
index The variable index

Discussion

The variable type index indicates the type of the variable. Either character, int, complex or real. The group type can be checked with the Cactus provided macros for CCTK_VARIABLE_INT, CCTK_VARIABLE_REAL, CCTK_VARIABLE_COMPLEX or CCTK_VARIABLE_CHAR.

Examples

C

index = CCTK_VarIndex("evolve::phi")
real = (CCTK_VARIABLE_REAL == CCTK_VarTypeI(index)) ;


Fortran

call CCTK_VARTYPEI(type,3)


### CCTK_VarTypeSize

Provides variable type size in bytes from the variable type index

Synopsis

C

#include "cctk.h"

int CCTK_VarTypeSize(int vtype);


Fortran

#include "cctk.h"

CCTK_INT size, vtype
call CCTK_VarTypeSize(size, vtype);


Parameters

vtype Variable type index.

Discussion

Given a CCTK_VARIABLE_* type code (e.g. CCTK_VARIABLE_INT, CCTK_VARIABLE_REAL, CCTK_VARIABLE_COMPLEX, etc.), this function returns the size in bytes of the corresponding data type (CCTK_INT, CCTK_REAL, CCTK_COMPLEX, etc.).

Errors

-1 vtype is not one of the CCTK_VARIABLE_* values.

### CCTK_VECTGFINDEX1D

Given a set of vector and multidimensional indices compute the 1-dimensional index into a vector grid function.

Synopsis

C

int CCTK_VECTGFINDEX1D(const cGH *restrict cctkGH, int i, int n)


Parameters

const cGH *restrict cctkGH The pointer to the CCTK grid hierarchy

int i Index in the i direction

int n The vector index

Discussion

Grid functions are held in memory as 1-dimensional C arrays. These are laid out in memory as in Fortran. Cactus provides macros to find the 1-dimensional index which is needed from the multidimensional indices which are usually used. In Fortran, grid functions are accessed as Fortran arrays.

Examples

C

for (i=0; i<cctk_lsh[0]; i++)
{
/* vector indices are 0, 1, 2 */
vel[CCTK_VECTGFINDEX4D(cctkGH,i,0)] = 1.0;
vel[CCTK_VECTGFINDEX4D(cctkGH,i,1)] = 0.0;
vel[CCTK_VECTGFINDEX4D(cctkGH,i,2)] = 0.0;
}


CCTK_GFINDEX1D() Given a set of multidimensional indices compute the 1-dimensional index into a grid function.

### CCTK_VECTGFINDEX2D

Given a set of vector and multidimensional indices compute the 2-dimensional index into a vector grid function.

Synopsis

C

int CCTK_VECTGFINDEX2D(const cGH *restrict cctkGH, int i, int j, int n)


Parameters

const cGH *restrict cctkGH The pointer to the CCTK grid hierarchy

int i Index in the i direction

int j Index in the j direction

int n The vector index

Discussion

Grid functions are held in memory as 1-dimensional C arrays. These are laid out in memory as in Fortran. Cactus provides macros to find the 1-dimensional index which is needed from the multidimensional indices which are usually used. In Fortran, grid functions are accessed as Fortran arrays.

Examples

C

for (j=0; j<cctk_lsh[1]; j++)
{
for (i=0; i<cctk_lsh[0]; i++)
{
/* vector indices are 0, 1, 2 */
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,0)] = 1.0;
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,1)] = 0.0;
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,2)] = 0.0;
}
}


CCTK_GFINDEX2D() Given a set of multidimensional indices compute the 2-dimensional index into a grid function.

### CCTK_VECTGFINDEX3D

Given a set of vector and multidimensional indices compute the 3-dimensional index into a vector grid function.

Synopsis

C

int CCTK_VECTGFINDEX3D(const cGH *restrict cctkGH, int i, int j, int k, int n)


Parameters

const cGH *restrict cctkGH The pointer to the CCTK grid hierarchy

int i Index in the i direction

int j Index in the j direction

int n The vector index

Discussion

Grid functions are held in memory as 1-dimensional C arrays. These are laid out in memory as in Fortran. Cactus provides macros to find the 1-dimensional index which is needed from the multidimensional indices which are usually used. In Fortran, grid functions are accessed as Fortran arrays.

Examples

C

for (k=0; k<cctk_lsh[2]; k++)
{
for (j=0; j<cctk_lsh[1]; j++)
{
for (i=0; i<cctk_lsh[0]; i++)
{
/* vector indices are 0, 1, 2 */
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,k,0)] = 1.0;
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,k,1)] = 0.0;
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,k,2)] = 0.0;
}
}
}


CCTK_GFINDEX3D() Given a set of multidimensional indices compute the 3-dimensional index into a grid function.

### CCTK_VECTGFINDEX4D

Given a set of vector and multidimensional indices compute the 4-dimensional index into a vector grid function.

Synopsis

C

int CCTK_VECTGFINDEX4D(const cGH *restrict cctkGH, int i, int j, int k, int l, int n)


Parameters

const cGH *restrict cctkGH The pointer to the CCTK grid hierarchy

int i Index in the i direction

int j Index in the j direction

int k Index in the k direction

int l Index in the l direction

int n The vector index

Discussion

Grid functions are held in memory as 1-dimensional C arrays. These are laid out in memory as in Fortran. Cactus provides macros to find the 1-dimensional index which is needed from the multidimensional indices which are usually used. In Fortran, grid functions are accessed as Fortran arrays.

Examples

C

for (l=0; l<cctk_lsh[3]; l++)
{
for (k=0; k<cctk_lsh[2]; k++)
{
for (j=0; j<cctk_lsh[1]; j++)
{
for (i=0; i<cctk_lsh[0]; i++)
{
/* vector indices are 0, 1, 2 */
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,k,l,0)] = 1.0;
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,k,l,1)] = 0.0;
vel[CCTK_VECTGFINDEX4D(cctkGH,i,j,k,l,2)] = 0.0;
}
}
}
}


CCTK_GFINDEX4D() Given a set of multidimensional indices compute the 4-dimensional index into a grid function.

### CCTK_VERROR

Prints a formatted string with a variable argument list as error message and stops the code

Synopsis

C

#include <cctk.h>

void CCTK_VERROR(const char *format, ...);


Parameters

format The printf-like format string to use for printing the warning message.
... The printf-style variable argument list.

Discussion

This routine can be used by thorns to print a formatted string followed by a variable argument list as error message to stderr. After printing the message, Cactus aborts the run (and CCTK_VERROR does not return to the caller).

This macro can be used by thorns to print an info message to screen.

The macro CCTK_VERROR(...) expands to a call to the underlying function CCTK_VError:

CCTK_VError(CCTK_THORNSTRING, ...)


So the macro automatically includes the name of the originating thorn in the info message. It is recommended that the macro CCTK_VERROR is used to print a message rather than calling CCTK_VError directly.

CCTK_Abort [A27] Abort the code
CCTK_ERROR [A158] macro to print an error message with a single string argument
CCTK_Exit [A166] Exit the code cleanly
CCTK_VWARN [A626] Possibly prints a formatted string with a variable argument list as warning message and/or stops the code
CCTK_WARN [A634] macro to print a warning message with a single string argument

Examples

C

#include <cctk.h>

const char *outdir;

CCTK_VERROR("Output directory ’%s’ could not be created", outdir);


### CCTK_VError

Prints a formatted string with a variable argument list as error message and stops the code

Synopsis

C

#include <cctk.h>

void CCTK_VError(int line,
const char *file,
const char *thorn,
const char *format,
...);


Parameters

line The line number in the originating source file where the CCTK_VError call occured. You can use the standardized __LINE__ preprocessor macro here.
file The file name of the originating source file where the CCTK_VError call occured. You can use the standardized __FILE__ preprocessor macro here.
thorn The thorn name of the originating source file where the CCTK_VError call occured. You can use the CCTK_THORNSTRING macro here (defined in cctk.h).
format The printf-like format string to use for printing the warning message.
... The variable argument list.

Discussion

This routine can be used by thorns to print a formatted string followed by a variable argument list as error message to stderr. After printing the message, Cactus aborts the run (and CCTK_VError does not return to the caller).

CCTK_Abort [A27] Abort the code
CCTK_ERROR [A158] macro to print an error message with a single string argument
CCTK_Exit [A166] Exit the code cleanly
CCTK_VWarn [A630] Possibly prints a formatted string with a variable argument list as warning message and/or stops the code
CCTK_WARN [A634] macro to print a warning message with a single string argument

Examples

C

#include <cctk.h>

const char *outdir;

CCTK_VError(__LINE__, __FILE__, CCTK_THORNSTRING,
"Output directory ’%s’ could not be created", outdir);


### CCTK_VINFO

Macro to print a printf-style variable argument list an information message to screen

Synopsis

C

#include <cctk.h>

CCTK_VINFO(const char *format, ...);


Result

0 ok

Parameters

format The printf-like format string to use for printing the info message.
... The variable argument list.

Discussion

This macro can be used by thorns to print an info message to screen.

The macro CCTK_VINFO(...) expands to a call to the underlying function CCTK_VInfo:

CCTK_VInfo(CCTK_THORNSTRING, ...)


So the macro automatically includes the name of the originating thorn in the info message. It is recommended that the macro CCTK_VINFO is used to print a message rather than calling CCTK_VInfo directly.

CCTK_ERROR [A158] macro to print an error message with a single string argument and stop the code CCTK_INFO() [A308] macro to print an info message with a single string argument to screen

CCTK_VERROR [A610] macro to print a formatted string with a variable argument list as error message and stops the code
CCTK_VWARN [A626] macro to print a warning message with a variable argument list
CCTK_WARN [A634] macro to print a warning message with a single string argument and possibly stop the code

Examples

C

#include <cctk.h>

const char *outdir;

CCTK_VINFO("Output files will go to ’%s’", outdir);


### CCTK_VInfo

Prints a formatted string with a variable argument list as an info message to sceen

Synopsis

C

#include <cctk.h>

int status = CCTK_VInfo(const char *thorn,
const char *format,
...);


Result

0 ok

Parameters

thorn The name of the thorn printing this info message. You can use the CCTK_THORNSTRING macro here (defined in cctk.h).
format The printf-like format string to use for printing the info message.
... The variable argument list.

Discussion

This routine can be used by thorns to print a formatted string with a variable argument list as an info message to screen. The message will include the name of the originating thorn, otherwise its semantics is equivalent to printf.

CCTK_INFO [A308] macro to print an info message with a single string argument
CCTK_ERROR [A158] macro to print an error message with a single string argument and stop the code
CCTK_VError [A613] prints a formatted string with a variable argument list as error message and stops the code
CCTK_VWarn [A630] prints a warning message with a variable argument list
CCTK_WARN [A634] macro to print a warning message with a single string argument and possibly stop the code

Examples

C

#include "cctk.h"

const char *outdir;

CCTK_VInfo(CCTK_THORNSTRING, "Output files will go to ’%s’", outdir);


### CCTK_VParamWarn

Prints a formatted string with a variable argument list as a warning from parameter checking, and possibly stops the code

Synopsis

C

#include <cctk.h>

int status = CCTK_VParamWarn(const char *thorn,
const char *format,
...);


Parameters

thorn Name of originating thorn
format Format for variable argument list
Variable argument list

Discussion

The call should be used in routines registered at the schedule point CCTK_PARAMCHECK to indicate that there is parameter error or conflict and the code should terminate. The code will terminate only after all the parameters have been checked.

Examples

C

CCTK_VParamWarn(CCTK_THORNSTRING, "Mass cannot be negative: %g", (double)mass);


CCTK_PARAMWARN [A450] Prints a warning from parameter checking, and possibly stops the code
CCTK_VPARAMWARN [A624] Prints a formatted string with a variable argument list as a warning from parameter checking, and possibly stops the code

### CCTK_VPARAMWARN

Prints a formatted string with a variable argument list as a warning from parameter checking, and possibly stops the code

Synopsis

C

#include <cctk.h>

int status = CCTK_VPARAMWARN(const char *format,
...);


Parameters

format Format for variable argument list
Variable argument list

Discussion

The call should be used in routines registered at the schedule point CCTK_PARAMCHECK to indicate that there is parameter error or conflict and the code should terminate. The code will terminate only after all the parameters have been checked.

Examples

C

CCTK_VPARAMWARN("Mass cannot be negative: %g", (double)mass);


CCTK_PARAMWARN [A450] Prints a warning from parameter checking, and possibly stops the code
CCTK_VParamWarn [A622] Prints a formatted string with a variable argument list as a warning from parameter checking, and possibly stops the code

### CCTK_VWARN

Possibly prints a formatted string with a variable argument list as warning message and/or stops the code

Synopsis

C

#include <cctk.h>

int status = CCTK_VWARN(int level,
const char *format,
...);


Result

0 ok

Parameters

level ($\ge 0$) The warning level for the message to print, with level 0 being the severest level and greater levels being less severe.
format The printf-like format string to use for printing the warning message.
... The printf-style variable argument list.

Discussion

This routine can be used by thorns to print a formatted string followed by a variable argument list as a warning message to stderr. If the message’s “warning level” is severe enough, then after printing the message Cactus aborts the run (and CCTK_VWARN does not return to the caller).

CCTK_VWARN(level, ...) expands to a call to CCTK_Warn() function which is equivalent to CCTK_VWarn(). The macro automatically includes details about the origin of the warning (the thorn name, the source code file name and the line number where the macro occurs).

Cactus’s behavior when CCTK_VWARN is called depends on the -W and -E command-line options:

• Cactus prints any warning with a warning level $\le$ the -W level to standard error (any warnings with warning levels $>$ the -W level are silently discarded). The default -W level is 1, i.e. only level 0 and level 1 warnings will be printed.

• Cactus stops (aborts) the current run for any warning with a warning level $\le$ the -E level. The default -W level is 0, i.e. only level 0 warnings will abort the run.

Cactus guarantees that . This implies that a message will always be printed for any warning that’s severe enough to halt the Cactus run. It also implies that a level 0 warning is guaranteed (to be printed and) to halt the Cactus run.

The severity level may actually be any integer, and a lot of existing code uses bare “magic number” integers for warning levels, but to help standardize warning levels across thorns, new code should probably use one of the following macros, defined in "cctk_WarnLevel.h" (which is #included by "cctk.h"):

#define CCTK_WARN_ABORT    0    /* abort the Cactus run */
#define CCTK_WARN_ALERT    1    /* the results of this run will probably */
/* be wrong, but this isn’t quite certain, */
/* so we’re not going to abort the run */
#define CCTK_WARN_COMPLAIN 2    /* the user should know about this, but */
/* the results of this run are probably ok */
#define CCTK_WARN_PICKY    3    /* this is for small problems that can */
/* probably be ignored, but that careful */
/* people may want to know about */
#define CCTK_WARN_DEBUG    4    /* these messages are probably useful */
/* only for debugging purposes */


For example, to provide a warning for a serious problem, which indicates that the results of the run are quite likely wrong, and which will be printed to the screen by default, a level CCTK_WARN_ALERT warning should be used.

In any case, the Boolean flesh parameter cctk_full_warnings determines whether all the details about the warning origin (processor ID, line number, source file, source thorn) are shown. The default is to print everything.

CCTK_Abort [A27] Abort the code
CCTK_ERROR [A158] macro to print an error message with a single string argument and stop the code
CCTK_Exit [A166] Exit the code cleanly
CCTK_INFO [A308] macro to print an info message with a single string argument
CCTK_VINFO() [A616] prints a formatted string with a variable argument list as an info message to screen
CCTK_VERROR [A610] prints a formatted string with a variable argument list as error message and stops the code
CCTK_WARN [A634] macro to print a warning message with a single string argument

Examples

C

#include <cctk.h>

const char *outdir;

"Output directory ’%s’ could not be created", outdir);


### CCTK_VWarn

Possibly prints a formatted string with a variable argument list as warning message and/or stops the code

Synopsis

C

#include <cctk.h>

int status = CCTK_VWarn(int level,
int line,
const char *file,
const char *thorn,
const char *format,
...);


Result

0 ok5

Parameters

level ($\ge 0$) The warning level for the message to print, with level 0 being the severest level and greater levels being less severe.
line The line number in the originating source file where the CCTK_VWarn call occured. You can use the standardized __LINE__ preprocessor macro here.
file The file name of the originating source file where the CCTK_VWarn call occured. You can use the standardized __FILE__ preprocessor macro here.
thorn The thorn name of the originating source file where the CCTK_VWarn call occured. You can use the CCTK_THORNSTRING macro here (defined in cctk.h).
format The printf-like format string to use for printing the warning message.
... The variable argument list.

Discussion

This routine can be used by thorns to print a formatted string followed by a variable argument list as a warning message to stderr. If the message’s “warning level” is severe enough, then after printing the message Cactus aborts the run (and CCTK_VWarn does not return to the caller).

Cactus’s behavior when CCTK_VWarn is called depends on the -W and -E command-line options:

• Cactus prints any warning with a warning level $\le$ the -W level to standard error (any warnings with warning levels $>$ the -W level are silently discarded). The default -W level is 1, i.e. only level 0 and level 1 warnings will be printed.

• Cactus stops (aborts) the current run for any warning with a warning level $\le$ the -E level. The default -W level is 0, i.e. only level 0 warnings will abort the run.

Cactus guarantees that . This implies that a message will always be printed for any warning that’s severe enough to halt the Cactus run. It also implies that a level 0 warning is guaranteed (to be printed and) to halt the Cactus run.

The severity level may actually be any integer, and a lot of existing code uses bare “magic number” integers for warning levels, but to help standardize warning levels across thorns, new code should probably use one of the following macros, defined in "cctk_WarnLevel.h" (which is #included by "cctk.h"):

#define CCTK_WARN_ABORT    0    /* abort the Cactus run */
#define CCTK_WARN_ALERT    1    /* the results of this run will probably */
/* be wrong, but this isn’t quite certain, */
/* so we’re not going to abort the run */
#define CCTK_WARN_COMPLAIN 2    /* the user should know about this, but */
/* the results of this run are probably ok */
#define CCTK_WARN_PICKY    3    /* this is for small problems that can */
/* probably be ignored, but that careful */
/* people may want to know about */
#define CCTK_WARN_DEBUG    4    /* these messages are probably useful */
/* only for debugging purposes */


For example, to provide a warning for a serious problem, which indicates that the results of the run are quite likely wrong, and which will be printed to the screen by default, a level CCTK_WARN_ALERT warning should be used.

In any case, the Boolean flesh parameter cctk_full_warnings determines whether all the details about the warning origin (processor ID, line number, source file, source thorn) are shown. The default is to print everything.

CCTK_Abort [A27] Abort the code
CCTK_ERROR [A158] macro to print an error message with a single string argument and stop the code
CCTK_Exit [A166] Exit the code cleanly
CCTK_INFO [A308] macro to print an info message with a single string argument
CCTK_VINFO() [A616] prints a formatted string with a variable argument list as an info message to screen
CCTK_VERROR [A610] prints a formatted string with a variable argument list as error message and stops the code
CCTK_WARN [A634] macro to print a warning message with a single string argument

Examples

C

#include <cctk.h>

const char *outdir;

"Output directory ’%s’ could not be created", outdir);


### CCTK_WARN

Macro to print a single string as a warning message and possibly stop the code

Synopsis

C

#include <cctk.h>

CCTK_WARN(int level, const char *message);


Fortran

#include "cctk.h"

call CCTK_WARN(level, message)
integer       level
character*(*) message


Parameters

level The warning level to use; see the description of CCTK_VWarn() on page A619 for a detailed discussion of this parameter and the Cactus macros for standard warning levels
message The warning message to print

Discussion

This macro can be used by thorns to print a single string as a warning message to stderr.

CCTK_WARN(level, message) expands to a call to CCTK_Warn() function which is equivalent to CCTK_VWarn(), but without the variable-number-of-arguments feature (so it can be used from Fortran).6 The macro automatically includes details about the origin of the warning (the thorn name, the source code file name and the line number where the macro occurs).

To include variables in a warning message from C, you can use the routine CCTK_VWarn which accepts a variable argument list. To include variables from Fortran, a string must be constructed and passed in a CCTK_WARN macro.

CCTK_Abort [A27] Abort the code
CCTK_ERROR [A158] macro to print an error message with a single string argument and stop the code
CCTK_Exit [A166] Exit the code cleanly
CCTK_ERROR [A158] macro to print an error message an abort the code
CCTK_INFO [A308] macro to print an info message with a single string argument
CCTK_VERROR [A610] macro to print a formatted string with a variable argument list as error message and stops the code
CCTK_VINFO [A616] macro to print a formatted string with a variable argument list as an info message to screen
CCTK_VWARN [A626] macro to print a warning message with a variable argument list

Examples

C

#include "cctk.h"

CCTK_WARN(CCTK_WARN_ABORT, "Divide by 0");


Fortran

#include "cctk.h"

integer       myint
real          myreal
character*200 message

write(message, ’(A32, G12.7, A5, I8)’)
&     ’Your warning message, including ’, myreal, ’ and ’, myint


### CCTK_Warn

Function to print a single string as error message and possibly stop the code

Synopsis

C

#include <cctk.h>

void CCTK_Warn(int level, int line_number, const char* file_name,
const char* thorn_name,const char* message)


Fortran

#include "cctk.h"

call CCTK_Warn(level, line_number, file_name, thorn_name, message)
integer level, line_number
character*(*) file_name, thorn_name, message


Parameters

level ($\ge 0$) The warning level for the message to print, with level 0 being the severest level and greater levels being less severe.
line_number The line number in the originating source file where the CCTK_VWarn call occured. You can use the standardized __LINE__ preprocessor macro here.
file_name The file name of the originating source file where the CCTK_VWarn call occured. You can use the standardized __FILE__ preprocessor macro here.
thorn_name The thorn name of the originating source file where the CCTK_VWarn call occured. You can use the CCTK_THORNSTRING macro here (defined in cctk.h).
message The error message to print

Discussion

The macro CCTK_WARN automatically includes the line number, file name and the name of the originating thorn in the info message. It is recommended that the macro CCTK_WARN is used to print a message rather than calling CCTK_Warn directly.

CCTK_Abort [A27] Abort the code
CCTK_Exit [A166] Exit the code cleanly
CCTK_INFO [A308] macro to print an info message
CCTK_VERROR [A610] macro to print an error message with a variable argument list
CCTK_VINFO [A616] macro to print an info message with a variable argument list
CCTK_VWARN [A626] macro to print a formatted string with a variable argument list as a warning message to standard error and possibly stops the code
CCTK_WARN [A634] Macro to print a single string as a warning message and possibly stop the code

### CCTK_WarnCallbackRegister

Register one or more routines for dealing with warning messages in addition to printing them to standard error

Synopsis

C

#include <cctk.h>

CCTK_WarnCallbackRegister(int minlevel,
int maxlevel,
void *data,
cctk_warnfunc callback);



Parameters

minlevel The minimum warning level to use.

You can find a detailed discussion of the Cactus macros for standard warning levels on page A619. Both minlevel and maxlevel follow that definition.

maxlevel The maximum warning level to use

data The void pointer holding extra information about the registered call back routine

callback The function pointer pointing to the call back function dealing with warning messages. The definition of the function pointer is:


typedef void (*cctk_warnfunc)(int level,
int line,
const char *file,
const char *thorn,
const char *message,
void *data);



The argument list is the same as those in CCTK_Warn() (see the footnote of CCTK_WARN() page A634) except an extra void pointer to hold the information about the call back routine.

Discussion

This function can be used by thorns to register their own routines to deal with warning messages. The registered function pointers will be stored in a pointer chain. When CCTK_VWarn() is called, the registered routines will be called in the same order as they get registered in addition to dumping warning messages to stderr.

The function can only be called in C.

CCTK_InfoCallbackRegister() Register one or more routines for dealing with information messages in addition to printing them to screen

CCTK_VWarn() Prints a formatted string with a variable argument list as a warning message to standard error and possibly stops the code

Examples

C

/*DumpWarn will dump warning messages to a file*/

void DumpWarn(int level,
int line,
const char *file,
const char *thorn,
const char *message,
void *data)
{
DECLARE_CCTK_PARAMETERS
FILE *fp;
char *str = (char *)malloc((strlen(file)+strlen(thorn)+strlen(message)+100);

/*warn_dump_file is a string set in the parameter file*/

if((fp = fopen (warn_dump_file, "a"))==0)
{
fprintf(stderr, "fatal error: can not open the file %s\n",warn_dump_file);
return;
}
sprintf(str, "\n[WARN]\nLevel->%d\nLine->%d\nFile->%s\nThorn->%s\nMsg->%s\n",
level,line,file,thorn,message);
fprintf(fp, "%s", str);
free(str);
fclose(fp);
}

...

/*minlevel = 0; maxlevel = 5; data = NULL; callback = DumpWarn*/

CCTK_WarnCallbackRegister(0,5,NULL,DumpWarn);


# Part BUtil_* Functions Reference

In this chapter all Util_*() Cactus utility functions are described. These are low-level functions mainly for more complicated programming, which are used by the rest of Cactus, but don’t depend heavily on it. Some of them are callable from Fortran or C, but many are C-only.

## Chapter B1Functions Alphabetically

Here the functions are listed alphabetically within each section.

### B1.1 Miscellaneous Functions

Util_CurrentDate

[B10] Fills string with current local date

Util_CurrentDateTime

[B12] Returns the current datetime in a machine-processable format as defined in ISO 8601 chapter 5.4.

Util_CurrentTime

[B14] Fills string with current local time

Util_snprintf

Util_vsnprintf

Util_asprintf

[B16] Sprintf with memory allocation. On input the buffer should point to a NULL area of memory.

### B1.2 String Functions

Util_StrCmpi

[B18] Compare two strings, ignoring upper/lower case.

Util_Strdup

Util_Strlcat

[B24] Concatenate two strings safely.

Util_Strlcpy

[B29] Copy a string safely.

Util_StrSep

[B34] Separate first token from a string.

### B1.3 Table Functions

Util_TableClone

[B39] Create a new table which is a “clone” (exact copy) of an existing table

Util_TableCreate

[B44] Create a new (empty) table

Util_TableCreateFromString

[B48] Create a new table (with the case-insensitive flag set) and sets values in it based on a string argument (interpreted with “parameter-file” semantics)

Util_TableDeleteKey

[B52] Delete a specified key/value entry from a table

Util_TableDestroy

[B55] Destroy a table

Util_TableGet*

[B59] This is a family of functions, one for each Cactus data type, to get the single (1-element array) value, or more generally the first array element of the value, associated with a specified key in a key/value table.

Util_TableGet*Array

[B63] This is a family of functions, one for each Cactus data type, to get a copy of the value associated with a specified key, and store it (more accurately, as much of it as will fit) in a specified array

Util_TableGetGeneric

[B67] Get the single (1-element array) value, or more generally the first array element of the value, associated with a specified key in a key/value table; the value’s data type is generic

Util_TableGetGenericArray

[B71] Get a copy of the value associated with a specified key, and store it (more accurately, as much of it as will fit) in a specified array; the array’s data type is generic

Util_TableGetString

[B75] Gets a copy of the character-string value associated with a specified key in a table, and stores it (more accurately, as much of it as will fit) in a specified character string

[B79] Advance a table iterator to the next entry in the table

Util_TableItClone

[B81] Creates a new table iterator which is a “clone” (exact copy) of an existing table iterator

Util_TableItCreate

[B85] Create a new table iterator

Util_TableItDestroy

[B88] Destroy a table iterator

Util_TableItQueryIsNonNull

[B90] Query whether a table iterator is not in the “null-pointer” state

Util_TableItQueryIsNull

[B93] Query whether a table iterator is in the “null-pointer” state

Util_TableItQueryKeyValueInfo

[B96] Query the key and the type and number of elements of the value corresponding to that key, of the table entry to which an iterator points

Util_TableItQueryTableHandle

[B100] Query what table a table iterator iterates over

Util_TableItResetToStart

[B102] Reset a table iterator to point to the starting table entry

Util_TableItSetToKey

[B104] Set a key/value iterator to point to a specified entry in the table.

Util_TableItSetToNull

[B106] Set a key/value iterator to the “null-pointer” state.

Util_TableQueryFlags

[B108] Query a table’s flags word

Util_TableQueryValueInfo

[B112] Query whether or not a specified key is in the table, and optionally the type and/or number of elements of the value corresponding to this key

Util_TableQueryMaxKeyLength

[B117] Query the maximum key length in a table

Util_TableQueryNKeys

[B120] Query the number of key/value entries in a table

Util_TableSet*

[B122] This is a family of functions, one for each Cactus data type, to set the value associated with a specified key to be a specified single (1-element array) value

Util_TableSet*Array

[B127] This is a family of functions, one for each Cactus data type, to set the value associated with a specified key to be a copy of a specified array

Util_TableSetFromString

[B131] Sets values in a table based on a string argument (interpreted with “parameter-file” semantics)

Util_TableSetGeneric

[B136] Set the value associated with a specified key to be a specified single (1-element array) value, whose data type is generic

Util_TableSetGenericArray

[B140] Set the value associated with a specified key to be a copy of a specified array, whose data type is generic

Util_TableSetString

[B145] Sets the value associated with a specified key in a table, to be a copy of a specified C-style null-terminated character string

Util_TablePrint

[B149] Print out a table and its data structures, using a verbose internal format meant for debugging

Util_TablePrintAll

[B152] Print out all tables and their data structures, using a verbose internal format meant for debugging

Util_TablePrintAllIterators

[B155] Print out all table iterators and their data structures, using a verbose internal format meant for debugging

Util_TablePrintPretty

[B158] Print out a table, using a human-readable format similar to the one accepted by Util_TableCreateFromString

## Chapter B2Full Descriptions of Miscellaneous Functions

### Util_CurrentDate

Fills string with current local date

Synopsis

C

#include "cctk.h"
#include "cctk_Misc.h.h"

int retval = Util_CurrentDate (int len, char *now);


Parameters

len length of the user-supplied string buffer
now user-supplied string buffer to write the date stamp to

Result

retval length of the string returned in now, or 0 if the string was truncated

Util_CurrentTime [B14] Fills string with current local time
Util_CurrentDateTime [B12] Returns the current datetime in a machine-processable format as defined in ISO 8601 chapter 5.4.

### Util_CurrentDateTime

Returns the current datetime in a machine-processable format as defined in ISO 8601 chapter 5.4.

Synopsis

C

#include "cctk.h"
#include "cctk_Misc.h.h"

char *current_datetime = Util_CurrentDateTime ();


Result

current_datetime Pointer to an allocated formatted string containing the current datetime stamp. The pointer should be freed by the caller.

Discussion

The formatted string returned contains the current datetime in a machine-processable format as defined in ISO 8601 chapter 5.4: "YYYY-MM-DDThh:mm:ss+hh:mm”

Util_CurrentDate [B10] Fills string with current local date
Util_CurrentTime [B14] Fills string with current local time

### Util_CurrentTime

Fills string with current local time

Synopsis

C

#include "cctk.h"
#include "cctk_Misc.h.h"

int retval = Util_CurrentTime (int len, char *now);


Parameters

len length of the user-supplied string buffer
now user-supplied string buffer to write the time stamp to

Result

retval length of the string returned in now, or 0 if the string was truncated

Util_CurrentDate [B10] Fills string with current local date
Util_CurrentDateTime [B12] Returns the current datetime in a machine-processable format as defined in ISO 8601 chapter 5.4.

### Util_asprintf

Sprintf with memory allocation. On input the buffer should point to a NULL area of memory.

Synopsis

C

#include "util_String.h"
int count = Util_asprintf(char** buffer, const char* format,
va_list arg)


Parameters

buffer Buffer to which to print the string.

*buffer should be NULL on entry. The routine allocates the memory, so the previous contents of the pointer are lost. On exit the buffer size will be count+1 (i.e the length of the string plus the \0).
format A (non-NULL pointer to a) C-style NUL-terminated string describing how to format any further arguments
... Zero or more further arguments, with types as specified by the format argument.

Discussion

This function is identical to sprintf(), except that it allocates a buffer large enough to hold the output including the terminating null byte, and returns a pointer to it via the first argument. This pointer should be passed to free() to release the allocated storage when it is no longer needed.

asprintf() GNU/BSD C library function which this function tries to clone.
sprintf() Unsafe and dangerous C library function similar to snprintf(), which doesn’t check the buffer length.

## Chapter B3Full Descriptions of String Functions

### Util_StrCmpi

Compare two strings, ignoring upper/lower case.

Synopsis

C

#include "util_String.h"
int cmp = Util_StrCmpi(const char *str1, const char *str2);


Result

cmp An integer which is:

 $<0$ if $\text{str1}<\text{str2}$ in lexicographic order ignoring upper/lower case distinctions $0$ if $\text{str1}=\text{str2}$ ignoring upper/lower case distinctions $>0$ if $\text{str1}>\text{str2}$ in lexicographic order ignoring upper/lower case distinctions

Parameters

str1 A non-NULL pointer to a (C-style NUL-terminated) string to be compared.
str2 A non-NULL pointer to a (C-style NUL-terminated) string to be compared.

Discussion

The standard C library strcmp() function does a case-sensitive string comparison, i.e. strcmp("cactus", "Cactus") will find the two strings not equal. Sometimes it’s useful to do case-insensitive string comparison, where upper/lower case distinctions are ignored. Many systems provide a strcasecmp() or strcmpi() function to do this, but some systems don’t, and even on those that do, the name isn’t standardised. So, Cactus provides its own version, Util_StrCmpi().

Notice that the return value of Util_StrCmpi(), like that of strcmp(), is zero (logical “false” in C) for equal strings, and nonzero (logical “true” in C) for non-equal strings. Code of the form

if (Util_StrCmpi(str1, str2))
{ /* strings differ */ }


or

if (!Util_StrCmpi(str1, str2))
{ /* strings are identical apart from case distinctions */ }


may be confusing to readers, because the sense of the comparison isn’t immediately obvious. Writing an explicit comparison against zero make make things clearer:

if (Util_StrCmpi(str1, str2) != 0)
{ /* strings differ */ }


or

if (Util_StrCmpi(str1, str2) == 0)
{ /* strings are identical apart from case distinctions */ }


Unfortunately, the basic concept of “case-insensitive” string operations doesn’t generalize well to non-English character sets,1 where lower-case $↔$ upper-case mappings may be context-dependent, many-to-one, and/or time-dependent.2 At present Cactus basically ignores these issues. :(

strcmp() Standard C library function (prototype in <string.h>) to compare two strings.

Examples

C

#include "util_String.h"

/* does the Cactus parameter  driver  specify the PUGH driver? */
/* (Cactus parameters are supposed to be case-insensitive) */
if (Util_StrCmpi(driver, "pugh") == 0)
{ /* PUGH code */ }
else
{ /* non-PUGH code */ }


### Util_Strlcat

Concatenate strings safely.

Synopsis

C

#include "util_String.h"
size_t result_len = Util_Strlcat(char *dst, const char *src, size_t size);


Result

result_len The size of the string the function tried to create, i.e. the initial strlen(dst) plus strlen(src).

Parameters

dst A non-NULL pointer to the (C-style NUL-terminated) destination string.
src A non-NULL pointer to the (C-style NUL-terminated) source string.
size The size of the destination buffer.

Discussion

The standard strcat() and strcpy() functions provide no way to specify the size of the destination buffer, so code using these functions is often vulnerable to buffer overflows. The standard strncat() and strncpy() functions can be used to write safe code, but their API is cumbersome, error-prone, and sometimes surprisingly inefficient:

• Their size arguments are the number of characters remaining in the destination buffer, which must often be calculated at run-time, and is prone to off-by-one errors.

• strncpy() doesn’t always NUL-terminate the destination string.

• strncpy() NUL-fills the remainder of the buffer not used for the source string; this NUL-filling can be very expensive.

To solve these problems, the OpenBSD project developed the strlcat() and strlcpy() functions. See http://www.openbsd.org/papers/strlcpy-paper.ps for a history and general discussion of these functions. Some other Unix systems (notably Solaris) now provide these, but many don’t, so Cactus provides its own versions, Util_Strlcat() and Util_Strlcpy().

Util_Strlcat() appends the NUL-terminated string src to the end of the NUL-terminated string dst. It will append at most size - strlen(dst) - 1 characters (hence it never overflows the destination buffer), and it always leaves dst string NUL-terminated.

strcat() Standard C library function (prototype in <string.h>) to concatenate two strings. This does not check that the buffer is big enough to hold the result, and is thus very dangerous. Use Util_Strlcat() instead!
Util_Strlcpy() [B29] Safely copy a string.

Examples

C

#include "util_String.h"

/*
* safely concatenate strings s1,s2,s3 into buffer:
* ... this code is safe (it will never overflow the buffer), but
*     quick-n-dirty in that it doesn’t give any error indication
*     if the result is truncated to fit in the buffer
*/
#define BUFFER_SIZE     1024
char buffer[BUFFER_SIZE];

Util_Strlcpy(buffer, s1, sizeof(buffer));
Util_Strlcat(buffer, s2, sizeof(buffer));
Util_Strlcat(buffer, s3, sizeof(buffer));


C

#include "util_String.h"

#define OK              0
#define ERROR_TRUNC     1

/*
* safely concatenate strings s1,s2,s3 into buffer[N_buffer];
* return OK if ok, ERROR_TRUNC if result was truncated to fit in buffer
*/
int cat3(int N_buffer, char buffer[],
const char s1[], const char s2[], const char s3[])
{
int length;

length = Util_Strlcpy(buffer, s1, N_buffer);
if (length >= N_buffer)
return ERROR_TRUNC;                   /*** ERROR EXIT ***/

length = Util_Strlcat(buffer, s2, N_buffer);
if (length >= N_buffer)
return ERROR_TRUNC;                   /*** ERROR EXIT ***/

length = Util_Strlcat(buffer, s3, N_buffer);
if (length >= N_buffer)
return ERROR_TRUNC;                   /*** ERROR EXIT ***/

return OK;                                    /*** NORMAL RETURN ***/
}


### Util_Strlcpy

Copies a string safely.

Synopsis

C

#include "util_String.h"
size_t result_len = Util_Strlcpy(char *dst, const char *src, size_t size);


Result

result_len The size of the string the function tried to create, i.e. strlen(src).

Parameters

dst A non-NULL pointer to the (C-style NUL-terminated) destination string.
src A non-NULL pointer to the (C-style NUL-terminated) source string.
size The size of the destination buffer.

Discussion

The standard strcat() and strcpy() functions provide no way to specify the size of the destination buffer, so code using these functions is often vulnerable to buffer overflows. The standard strncat() and strncpy() functions can be used to write safe code, but their API is cumbersome, error-prone, and sometimes surprisingly inefficient:

• Their size arguments are the number of characters remaining in the destination buffer, which must often be calculated at run-time, and is prone to off-by-one errors.

• strncpy() doesn’t always NUL-terminate the destination string.

• strncpy() NUL-fills the remainder of the buffer not used for the source string; this NUL-filling can be very expensive.

To solve these problems, the OpenBSD project developed the strlcat() and strlcpy() functions. See http://www.openbsd.org/papers/strlcpy-paper.ps for a history and general discussion of these functions. Some other Unix systems (notably Solaris) now provide these, but many don’t, so Cactus provides its own versions, Util_Strlcat() and Util_Strlcpy().

Util_Strlcpy() copies up to size-1 characters from the source string to the destination string, followed by a NUL character (so dst is always NUL-terminated). Unlike strncpy(), Util_Strlcpy() does not fill any left-over space at the end of the destination buffer with NUL characters.

strcpy() Standard C library function (prototype in <string.h>) to copy a string to a buffer. This does not check that the buffer is big enough to hold the string, and is thus very dangerous. Use Util_Strlcpy() instead!
Util_Strlcat() [B24] Safely concatenates two strings.

Examples

C

#include "util_String.h"

/*
* safely concatenate strings s1,s2,s3 into buffer:
* ... this code is safe (it will never overflow the buffer), but
*     quick-n-dirty in that it doesn’t give any error indication
*     if the result is truncated to fit in the buffer
*/
#define BUFFER_SIZE     1024
char buffer[BUFFER_SIZE];

Util_Strlcpy(buffer, s1, sizeof(buffer));
Util_Strlcat(buffer, s2, sizeof(buffer));
Util_Strlcat(buffer, s3, sizeof(buffer));


C

#include "util_String.h"

#define OK              0
#define ERROR_TRUNC     1

/*
* safely concatenate strings s1,s2,s3 into buffer[N_buffer];
* return OK if ok, ERROR_TRUNC if result was truncated to fit in buffer
*/
int cat3(int N_buffer, char buffer[],
const char s1[], const char s2[], const char s3[])
{
int length;

length = Util_Strlcpy(buffer, s1, N_buffer);
if (length >= N_buffer)
return ERROR_TRUNC;                   /*** ERROR EXIT ***/

length = Util_Strlcat(buffer, s2, N_buffer);
if (length >= N_buffer)
return ERROR_TRUNC;                   /*** ERROR EXIT ***/

length = Util_Strlcat(buffer, s3, N_buffer);
if (length >= N_buffer)
return ERROR_TRUNC;                   /*** ERROR EXIT ***/

return OK;                                    /*** NORMAL RETURN ***/
}


### Util_StrSep

Separate off the first token from a string.

Synopsis

C

#include "util_String.h"
char* token = Util_StrSep(const char** string_ptr, const char* delim_set);


Result

token This function returns the original value of *string_ptr, or NULL if the end of the string is reached.

Parameters

string_ptr A non-NULL pointer to a (modifyable) non-NULL pointer to the (C-style NUL-terminated) string to operate on.
delim_set A non-NULL pointer to a (C-style NUL-terminated) string representing a set of delimiter characters (the order of these characters doesn’t matter).

Discussion

Many Unix systems define a function strsep() which provides a clean way of splitting a string into “words”. However, some systems only provide the older (and inferior-in-several-ways) strtok() function, so Cactus implements its own strsep() function, Util_StrSep().

Util_StrSep() finds the first occurence in the string pointed to by *string_ptr of any character in the string pointed to by delim_set (or the terminating NUL if there is no such character), and replaces this by NUL. The location of the next character after the NUL character just stored (or NULL, if the end of the string was reached) is stored in *string_ptr.

An “empty” field, i.e. one caused by two adjacent delimiter characters, can be detected (after Util_StrSep() returns) by the test **string_ptr == ’\0’, or equivalently strlen(*string_ptr) == 0.

See the example section below for the typical usage of Util_StrSep().

strsep() Some systems provide this in the standard C library (prototype in <string.h>); Util_StrSep() is a clone of this.
strtok() Inferior API for splitting a string into tokens (defined by the ANSI/ISO C standard).

Examples

C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "util_String.h"

/* prototypes */
int parse_string(char* string,
int N_argv, char* argv[]);

/*
* Suppose we have a Cactus parameter  gridfn_list  containing a
* whitespace-separated list of grid functions.  This function
* "processes" (here just prints the name of) each grid function.
*/
void process_gridfn_list(const char* gridfn_list)
{
#define MAX_N_GRIDFNS   100
int N_gridfns;
int i;
char* copy_of_gridfn_list;
char* gridfn[MAX_N_GRIDFNS];

copy_of_gridfn_list = strdup(gridfn_list);
N_gridfns = parse_string(copy_of_gridfn_list,
MAX_N_GRIDFNS, gridfn);

for (i = 0 ; i < N_gridfns ; ++i)
{
/* "process" (here just print the name of) each gridfn */
printf("grid function %d is \"%s\"\n", i, gridfn[i]);
}

free(copy_of_gridfn_list);
}

/*
* This function parses a string containing whitespace-separated
* tokens into a main()-style argument vector (of size  N_argv ).
* This function returns the number of pointers stored into  argv[] .
*
* Adjacent sequences of whitespace are treated the same as single
* whitespace characters.
*
* Note that this function this modifies its input string.
*/

int parse_string(char* string,
int N_argv, char* argv[])
{
int i;

for (i = 0 ; i < N_argv ; )
{
argv[i] = Util_StrSep(&string, " \t\n\r\v");
if (argv[i] == NULL)
{ break; }      /* reached end-of-string */

if (*argv[i] == ’\0’)
{
/*
* found a 0-length "token" (a sequence of
* two or more adjacent whitespace characters)
* ==> skip this "token" (don’t store it)
* ==> no-op here
*/
}
else {
/* token has length > 0 ==> store it */
++i;
}
}

return i;
}


## Chapter B4Full Descriptions of Table Functions

### Util_TableClone

Creates a new table which is a “clone” (exact copy) of an existing table

Synopsis

C

#include "util_ErrorCodes.h"
#include "util_Table.h"
int clone_handle = Util_TableClone(int handle);


Fortran

call Util_TableClone(clone_handle, handle)
integer clone_handle, handle


Result

clone_handle ($\ge 0$) A handle to the clone table

Parameters

handle Handle to the table to be cloned

Discussion

Viewing a table as a set of key/value pairs, this function creates a new table (with the same flags word as the original) containing copies of all the original table’s key/value pairs. The two tables are completely independent, i.e. future changes to one won’t affect the other.

Note that if there are any CCTK_POINTER and/or CCTK_FPOINTER values in the table, they are “shallow copied”, i.e. the (pointer) values in the table are copied. This results in the clone table’s pointer values pointing to the same places as the original table’s pointer values. Be careful with this! In particular, if you’re using pointer values in the table to keep track of malloc() memory, be careful not to free() the same block of memory twice!

Note that table iterators are not guaranteed to sequence through the original and clone tables in the same order. (This is a special case of the more general “non-guarantee” in the Section of table iterators in the Users’ Guide: the order of table iterators may differ even between different tables with identical key/value contents.)

Util_TableCreate() [B44] create a table
Util_TableCreateFromString() [B48] convenience routine to create a table and set key/value entries in it based on a parameter-file–like character string
Util_TableDestroy() [B55] destroy a table

Errors

UTIL_ERROR_NO_MEMORY unable to allocate memory
UTIL_ERROR_TABLE_BAD_FLAGS flags word is negative in the to-be-cloned table (this indicates an internal error in the table routines, and should never happen)

Examples

C

#include "util_ErrorCodes.h"
#include "util_Table.h"

/*
* This function is passed (a handle to) a table containing some entries.
* It needs to set some additional entries and pass the table to some
* other function(s), but it also needs to leave the original table
* intact for other use by the caller.  The solution is to clone the
* original table and work on the clone, leaving the original table
* unchanged.
*/
int my_function(int handle, int x, int y)
{
int status;

/* clone the table */
const int clone_handle = Util_TableClone(handle)
if (clone_handle < 0)
return clone_handle;               /* error in cloning table */

/* now set our entries in the clone table */
status = Util_TableSetInt(clone_handle, x, "x");
if (status < 0)
return status;                     /* error in setting x */
status = Util_TableSetInt(clone_handle, y, "y");
if (status < 0)
return status;                     /* error in setting y */

/* ... code to use the clone table ... */
/* ... eg pass clone_handle to other functions ... */

/* we’re done with the clone now */
Util_TableDestroy(clone_handle);
return 0;
}


### Util_TableCreate

Creates a new (empty) table

Synopsis

C

#include "util_ErrorCodes.h"
#include "util_Table.h"
int handle = Util_TableCreate(int flags);


Fortran

call Util_TableCreate(handle, flags)
integer handle, flags


Result

handle ($\ge 0$) A handle to the newly-created table

Parameters

flags ($\ge 0$) A flags word for the table. This should be the inclusive-or of zero or more of the UTIL_TABLE_FLAGS_* bit masks (defined in "util_Table.h"). For Fortran users, note that inclusive-or is the same as sum here, since the bit masks are all disjoint.

Discussion

We require the flags word to be non-negative so that other functions can distinguish flags from (negative) error codes.

Any User-defined flag words should use only bit positions at or above
UTIL_TABLE_FLAGS_USER_DEFINED_BASE, i.e. all bit positions below this are reserved for present of future Cactus use.

At present there is only a single flags-word bit mask defined in "util_Table.h":

UTIL_TABLE_FLAGS_CASE_INSENSITIVE

By default keys are treated as C-style character strings, and the table functions compare them with the standard C strcmp function. However, by setting the
UTIL_TABLE_FLAGS_CASE_INSENSITIVE bit in the flags word, this table’s keys may be made case-insensitive, i.e. the table routines then compare this table’s keys with Util_StrCmpi(). Note that keys are still stored exactly as the caller specifies them (i.e. they are not forced into a canonical case); it’s only their comparison that’s affected by this flag.

Util_StrCmpi() [B18] compare two strings, ignoring upper/lower case
Util_TableClone() [B39] create a new table which is a “clone” (exact copy) of an existing table
Util_TableCreateFromString() [B48] convenience routine to create a table and set key/value entries in it based on a parameter-file–like character string
Util_TableDestroy() [B55] destroy a table

Errors

UTIL_ERROR_NO_MEMORY unable to allocate memory

Examples

C

#include "util_ErrorCodes.h"
#include "util_Table.h"

/* create a table, simplest case */
int handle = Util_TableCreate(UTIL_TABLE_FLAGS_DEFAULT);

/* create a table whose keys will be treated as case-insensitive */
int handle2 = Util_TableCreate(UTIL_TABLE_FLAGS_CASE_INSENSITIVE);


### Util_TableCreateFromString

Creates a new table (with the case-insensitive flag set) and sets values in it based on a string argument (interpreted with “parameter-file” semantics)

Synopsis

C

#include "util_ErrorCodes.h"
#include "util_Table.h"
int handle = Util_TableCreateFromString(const char *string);


Fortran

call Util_TableCreateFromString(handle, string)
integer       handle
character*(*) string


Result

handle ($\ge 0$) a handle to the newly-created table

Parameters

string a pointer to a C-style null-terminated string specifying the table contents; see the description for Util_TableSetFromString() for a full description of the syntax and semantics of this string

Util_TableClone() [B39] Create a new table which is a “clone” (exact copy) of an existing table
Util_TableCreate() [B44] create a table
Util_TableSetFromString() [B131] sets values in a table based on a string argument

Errors

UTIL_ERROR_NO_MEMORY unable to allocate memory
UTIL_ERROR_BAD_KEY invalid input: key contains invalid character
UTIL_ERROR_BAD_INPUT invalid input: can’t parse input string
other error codes this function may also return any error codes returned by Util_TableCreate() or Util_TableSetFromString()

Examples

C

#include "util_ErrorCodes.h"
#include "util_Table.h"

int handle = Util_TableCreateFromString("order = 3\t"
"myreal = 42.314159\t"
"mystring = ’hello’\t"
"myarray = { 0 1 2 3 }");

/* equivalent code to the above */
int handle = Util_TableCreate(UTIL_TABLE_FLAGS_CASE_INSENSITIVE);
Util_TableSetFromString(handle, "order = 3\t"
"myreal = 42.314159\t"
"mystring = ’hello’"
"myarray = { 0 1 2 3 }");

/* also equivalent to the above */
int handle = Util_TableCreate(UTIL_TABLE_FLAGS_CASE_INSENSITIVE);
CCTK_INT array[] = {0, 1, 2, 3};

Util_TableSetInt(handle, 3, "order");
Util_TableSetReal(handle, 42.314159, "myreal");
Util_TableSetString(handle, "hello", "mystring");
Util_TableSetIntArray(handle, 4, array, "myarray");


### Util_TableDeleteKey

Deletes a specified key/value entry from a table

Synopsis

C

#include "util_ErrorCodes.h"
#include "util_Table.h"
int key_exists = Util_TableDeleteKey(int handle, const char *key);


Fortran

call Util_TableDeleteKey(key_exists, handle, key)
integer        key_exists, handle
character*(*)  key


Result

0 ok (key existed before this call, and has now been deleted)

Parameters

handle ($\ge 0$) handle to the table
key a pointer to the key (a C-style null-terminated string)

Discussion

This function invalidates any iterators for the table which are not in the “null-pointer” state.

Errors

UTIL_ERROR_TABLE_NO_SUCH_KEY no such key in table

### Util_TableDestroy

Destroys a table

Synopsis

C

#include "util_ErrorCodes.h"
#include "util_Table.h"
int status = Util_TableDestroy(int handle);


Fortran

call Util_TableDestroy(status, handle)
integer status, handle


Result

0 ok

Parameters

handle ($\ge 0$) handle to the table

Discussion

Of course, this function invalidates any and all iterators for the table. :)

Util_TableClone() [B39] Create a new table which is a “clone” (exact copy) of an existing table
Util_TableCreate() [B44] create a table
Util_TableCreateFromString() [B48] convenience routine to create a table and set key/value entries in it based on a parameter-file–like character string

Errors

Examples

C

#include "util_ErrorCodes.h"
#include "util_Table.h"

/* create a table */
int handle = Util_TableCreate(UTIL_TABLE_FLAGS_DEFAULT);

/* do things with the table: put values in it, */
/* pass its handle to other functions, etc etc */
/* ... */

/* at this point we (and all other functions we */
/* may call in the future) are done with the table */
Util_TableDestroy(handle);


### Util_TableGet*

This is a family of functions, one for each Cactus data type, to get the single (1-element array) value, or more generally the first array element of the value, associated with a specified key in a key/value table.

Synopsis

C

#include "util_ErrorCodes.h"
#include "util_Table.h"
int N_elements = Util_TableGetXxx(int handle,
CCTK_XXX *value,
const char *key);


where XXX is one of POINTER, FPOINTER1 , CHAR, BYTE, INT, INT1, INT2, INT4, INT8, REAL, REAL4, REAL8, REAL16, COMPLEX, COMPLEX8, COMPLEX16, COMPLEX32 (not all of these may be supported on any given system)

Fortran

call Util_TableGetXxx(N_elements, handle, value, key)
integer        N_elements, handle
CCTK_XXX       value
character*(*)  key


where CCTK_XXX may be any data type supported by C (above) except CCTK_CHAR (Fortran doesn’t have a separate “character” data type; use CCTK_BYTE instead)

Result

N_elements the number of array elements in the value

Parameters

handle ($\ge 0$) handle to the table
value a pointer to where this function should store a copy of the value (or more generally the first array element of the value) associated with the specified key, or NULL pointer to skip storing this
key a pointer to the key (a C-style null-terminated string)

Discussion

Note that it is not an error for the value to actually have $>1$ array elements; in this case only the first element is stored. The rationale for this design is that the caller may know or suspect that the value is a large array, but may only want the first array element; in this case this design avoids the caller having to allocate a large buffer unnecessarily.

In contrast, it is an error for the value to actually be an empty (0-length) array, because then there is no “first array element” to get.

It is also an error for the value to actually have a different type than CCTK_XXX.

If any error code is returned, the user’s value buffer (pointed to by value if this is non-NULL) is unchanged.

Util_TableCreateFromString() [B48] convenience routine to create a table and set key/value entries in it based on a parameter-file–like character string
Util_TableGet*Array() get an array value
Util_TableGetString() [B75] get a character-string value
Util_TableSet*() set a single (1-element array) value
Util_TableSet*Array() set an array value
Util_TableSetGeneric() [B136] set a single (1-element array) value with generic data type
Util_TableSetGenericArray() [B140] set an array value with generic data type
Util_TableSetFromString() [B131] convenience routine to set key/value entries in a table based on a parameter-file–like character string
Util_TableSetString() [B145] set a character-string value

Errors

UTIL_ERROR_TABLE_NO_SUCH_KEY no such key in table
UTIL_ERROR_TABLE_WRONG_DATA_TYPE value has data type other than CCTK_TYPE
UTIL_ERROR_TABLE_VALUE_IS_EMPTY value is an empty (0-element) array

Examples

C

#include "util_ErrorCodes.h"
#include "util_Table.h"

#define N_DIGITS        5
static const CCTK_INT pi_digits[N_DIGITS] = {3, 14, 159, 2653, 58979};

int N;
CCTK_INT x;
int handle = Util_TableCreate(UTIL_TABLE_FLAGS_DEFAULT);

Util_TableSetIntArray(handle, N_DIGITS, pi_digits, "digits of pi");
Util_TableSetIntArray(handle, 0, pi_digits, "empty array");

/* gets N = 5, x = 3 */
N = Util_TableGetInt(handle, &x, "digits of pi");

/* gets N = UTIL_ERROR_TABLE_VALUE_IS_EMPTY */
N = Util_TableGetInt(handle, &x, "empty array");


### Util_TableGet*Array

This is a family of functions, one for each Cactus data type, to get a copy of the value associated with a specified key, and store it (more accurately, as much of it as will fit) in a specified array

Synopsis

C

#include "util_ErrorCodes.h"
#include "util_Table.h"
int N_elements = Util_TableGetXxxArray(int handle,
int N_array, CCTK_XXX array[],
const char *key);


where XXX is one of POINTER, FPOINTER2 , CHAR, BYTE, INT, INT1, INT2, INT4, INT8, REAL, REAL4, REAL8, REAL16, COMPLEX, COMPLEX8, COMPLEX16, COMPLEX32 (not all of these may be supported on any given system)

Fortran

call Util_TableGetXxxArray(N_elements, handle, N_array, array, key)
integer        N_elements, handle, N_array
CCTK_XXX(*)    array
character*(*)  key


where CCTK_XXX may be any data type supported by C (above)

Result

N_elements the number of array elements in the value

Parameters

handle ($\ge 0