17.2.248. MPI_Issend

MPI_Issend - Starts a nonblocking synchronous send.

17.2.248.1. SYNTAX

17.2.248.1.1. C Syntax

#include <mpi.h>

int MPI_Issend(const void *buf, int count, MPI_Datatype datatype, int dest,
     int tag, MPI_Comm comm, MPI_Request *request)

17.2.248.1.2. Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_ISSEND(BUF, COUNT, DATATYPE, DEST, TAG, COMM, REQUEST, IERROR)
     <type>  BUF(*)
     INTEGER COUNT, DATATYPE, DEST, TAG, COMM, REQUEST, IERROR

17.2.248.1.3. Fortran 2008 Syntax

USE mpi_f08
MPI_Issend(buf, count, datatype, dest, tag, comm, request, ierror)
     TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: buf
     INTEGER, INTENT(IN) :: count, dest, tag
     TYPE(MPI_Datatype), INTENT(IN) :: datatype
     TYPE(MPI_Comm), INTENT(IN) :: comm
     TYPE(MPI_Request), INTENT(OUT) :: request
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror

17.2.248.2. INPUT PARAMETERS

  • buf: Initial address of send buffer (choice).

  • count: Number of elements in send buffer (integer).

  • datatype: Datatype of each send buffer element (handle).

  • dest: Rank of destination (integer).

  • tag: Message tag (integer).

  • comm: Communicator (handle).

17.2.248.3. OUTPUT PARAMETERS

  • request: Communication request (handle).

  • IERROR: Fortran only: Error status (integer).

17.2.248.4. DESCRIPTION

Starts a synchronous mode, nonblocking send.

Nonblocking calls allocate a communication request object and associate it with the request handle (the argument request). The request can be used later to query the status of the communication or wait for its completion.

A nonblocking send call indicates that the system may start copying data out of the send buffer. The sender should not modify any part of the send buffer after a nonblocking send operation is called, until the send completes.

17.2.248.5. ERRORS

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.

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_Ssend