MPI_Isend(3OpenMPI) MPI_Isend(3OpenMPI)
NAME
MPI_Isend - Starts a standard-mode, nonblocking send.
SYNTAX
C Syntax
#include <mpi.h>
int MPI_Isend(void *buf, int count, MPI_Datatype datatype, int dest,
int tag, MPI_Comm comm, MPI_Request *request)
Fortran Syntax
INCLUDE 'mpif.h'
MPI_ISEND(BUF, COUNT, DATATYPE, DEST, TAG, COMM, REQUEST, IERROR)
<type> BUF(*)
INTEGER COUNT, DATATYPE, DEST, TAG, COMM, REQUEST, IERROR
C++ Syntax
#include <mpi.h>
Request Comm::Isend(const void* buf, int count, const
Datatype& datatype, int dest, int tag) const
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).
OUTPUT PARAMETERS
request Communication request (handle).
IERROR Fortran only: Error status (integer).
DESCRIPTION
MPI_Isend starts a standard-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 access any part of the send buffer after a nonblocking send operation is called,
until the send completes.
A send request can be determined being completed by calling the MPI_Wait, MPI_Waitany, MPI_Test, or
MPI_Testany with request returned by this function.
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_Send MPI_Wait MPI_Waitany MPI_Test MPI_Testany
Open MPI 1.2 March 2007 MPI_Isend(3OpenMPI)
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