MPI_T_init_thread(3) Open MPI MPI_T_init_thread(3)
NAME
MPI_T_init_thread - Initializes the MPI Tool imformation interface
SYNTAX
C Syntax
#include <mpi.h>
int MPI_T_init_thread(int required, int *provided)
INPUT PARAMETERS
required Desired level of thread support (integer).
OUTPUT PARAMETERS
provided Available level of thread support (integer).
DESCRIPTION
MPI_T_init_thread() initializes the MPI tool information interface.
Calls to MPI tool functions are allowed at any point in execution (in-
cluding before MPI_Init() and after MPI_Finalize()) as long as
MPI_T_init_thread() has been called at least once and the number of
calls to MPI_T_init_thread() is greater than the number of calls to
MPI_T_finalize(). If at any point in execution the number of calls to
MPI_T_finalize() equals the number of calls to MPI_T_init_thread() the
MPI tool interface will no longer be available until another call to
MPI_T_init_thread().
MPI_T_init_thread, like MPI_Init_thread, has a provision to request a
certain level of thread support in required:
MPI_THREAD_SINGLE Only one thread will execute.
MPI_THREAD_FUNNELED If the process is multithreaded, only the
thread that called MPI_Init_thread will make
MPI calls.
MPI_THREAD_SERIALIZED If the process is multithreaded, only one
thread will make MPI library calls at one time.
MPI_THREAD_MULTIPLE If the process is multithreaded, multiple
threads may call MPI at once with no restric-
tions.
The level of thread support available to the program is set in pro-
vided. In Open MPI, the value is dependent on how the library was con-
figured and built. Note that there is no guarantee that provided will
be greater than or equal to required.
NOTES
It is the caller's responsibility to check the value of provided, as it
may be less than what was requested in required.
ERRORS
MPI_T_init_thread() will fail if:
[MPI_T_ERR_MEMORY]
Out of memory
[MPI_T_ERR_CANNOT_INIT]
Interface not in the state to be initialized
SEE ALSO
MPI_Init_thread
MPI_T_finalize
4.1.2 Nov 24, 2021 MPI_T_init_thread(3)
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