MPI_Start(3)                       Open MPI                       MPI_Start(3)



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++
       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 ALSO
       MPI_Bsend_init
       MPI_Rsend_init
       MPI_Send_init
       MPI_Sssend_init
       MPI_Recv_init
       MPI_Startall





1.4.1                            Jan 14, 2010                     MPI_Start(3)
