MPI_Start(3OpenMPI)													       MPI_Start(3OpenMPI)

NAME

       MPI_Start - Initiates a communication using a persistent request handle.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Start(MPI_Request *request)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_START(REQUEST, IERROR)
	    INTEGER   REQUEST, IERROR

C++ Syntax
       #include <mpi.h>
       void Prequest::Start()

INPUT PARAMETER

       request	 Communication request (handle).

OUTPUT PARAMETER

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       A communication (send or receive) that uses a persistent request is initiated by the function MPI_Start.

       The  argument,  request,  is  a	handle	returned  by  one of the persistent communication-request initialization functions (MPI_Send_init,
       MPI_Bsend_init,	MPI_Ssend_init, MPI_Rsend_init, MPI_Recv_init). The associated request should be inactive and becomes active once the call
       is made.

       If  the	request is for a send with ready mode, then a matching receive should be posted before the call is made. From the time the call is
       made until after the operation completes, the communication buffer should not be accessed.

       The call is local, with semantics similar to the nonblocking communication operations (see Section 3.7 in the MPI-1 Standard,  "Nonblocking
       Communication.")  That  is, a call to MPI_Start with a request created by MPI_Send_init starts a communication in the same manner as a call
       to MPI_Isend; a call to MPI_Start with a request created by MPI_Bsend_init starts  a  communication  in	the  same  manner  as  a  call	to
       MPI_Ibsend; and so on.

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 ALSO

       MPI_Bsend_init
       MPI_Rsend_init
       MPI_Send_init
       MPI_Sssend_init
       MPI_Recv_init
       MPI_Startall

Open MPI 1.2							  September 2006					       MPI_Start(3OpenMPI)