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 initial-ization initialization
ization 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
Open MPI 1.2 September 2006 MPI_Start(3OpenMPI)
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