oracular (3) MPI_Start.openmpi.3.gz

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

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_START(REQUEST, IERROR)
            INTEGER   REQUEST, IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Start(request, ierror)
            TYPE(MPI_Request), INTENT(INOUT) :: request
            INTEGER, OPTIONAL, INTENT(OUT) :: 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