oracular (3) MPI_Is_thread_main.openmpi.3.gz

NAME

       MPI_Is_thread_main - Determines if thread called MPI_Init

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Is_thread_main(int *flag)

Fortran Syntax

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_IS_THREAD_MAIN(FLAG, IERROR)
            LOGICAL   FLAG
            INTEGER   IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Is_thread_main(flag, ierror)
            LOGICAL, INTENT(OUT) :: flag
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       bool MPI::Is_thread_main()

OUTPUT PARAMETERS

       flag      True if calling thread is main thread (boolean).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_Is_thread_main  is called by a thread to find out whether the caller is the main thread (that is, the
       thread that called MPI_Init or MPI_Init_thread).

ERRORS

       Almost all MPI routines return an error value; C routines as  the  value  of  the  function  and  Fortran
       routines in the last argument. C++ functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the  C++  exception  mechanism  will  be  used  to  throw  an
       MPI::Exception object.

       Before  the  error  value  is  returned,  the current MPI error handler is called. By default, this error
       handler aborts the MPI job, except for I/O function  errors.  The  error  handler  may  be  changed  with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values
       to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

       See the MPI man page for a full list of MPI error codes.

SEE ALSO

       MPI_Init
       MPI_Init_thread