mpi_is_thread_main(3openmpi) [osx man page]

MPI_Is_thread_main(3OpenMPI)											      MPI_Is_thread_main(3OpenMPI)

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
       INCLUDE 'mpif.h'
       MPI_IS_THREAD_MAIN(FLAG, IERROR)
	    LOGICAL   FLAG
	    INTEGER   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++ func-
       tions  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

Open MPI 1.2							  September 2006				      MPI_Is_thread_main(3OpenMPI)

MPI_Init(3OpenMPI)														MPI_Init(3OpenMPI)

NAME

       MPI_Init - Initializes the MPI execution environment

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Init(int *argc, char ***argv)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_INIT(IERROR)
	    INTEGER   IERROR

C++ Syntax
       #include <mpi.h>
       void MPI::Init(int& argc, char**& argv)
       void MPI::Init()

INPUT PARAMETERS

       argc	 C/C++ only: Pointer to the number of arguments.

       argv	 C/C++ only: Argument vector.

OUTPUT PARAMETER

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       This  routine,  or MPI_Init_thread, must be called before any other MPI routine (apart from MPI_Initialized) is called. MPI can be initial-
       ized at most once; subsequent calls to MPI_Init or MPI_Init_thread are erroneous.

       All MPI programs must contain a call to MPI_Init or MPI_Init_thread. Open MPI accepts the C/C++ argc and argv arguments to main,  but  nei-
       ther modifies, interprets, nor distributes them:

	    {
		 /* declare variables */
		 MPI_Init(&argc, &argv);
		 /* parse arguments */
		 /* main program */
		 MPI_Finalize();
	    }

NOTES

       The Fortran version does not have provisions for argc and argv and takes only IERROR.

       The  MPI Standard does not say what a program can do before an MPI_Init or after an MPI_Finalize. In the Open MPI implementation, it should
       do as little as possible. In particular, avoid anything that changes the external state of the program,	such  as  opening  files,  reading
       standard input, or writing to standard output.

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++ func-
       tions 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_thread
       MPI_Initialized
       MPI_Finalize

Open MPI 1.2							  September 2006						MPI_Init(3OpenMPI)