MPI_Improbe - Non-blocking matched probe for a message.

NAME SYNTAX C Syntax Fortran Syntax Fortran 2008 Syntax INPUT PARAMETERS OUTPUT PARAMETERS DESCRIPTION NOTE ERRORS SEE ALSO

NAME

MPI_Improbe − Non-blocking matched probe for a message.

C Syntax

#include <mpi.h>
int MPI_Improbe(int source, int tag, MPI_Comm comm,

int *flag, MPI_Message *message, MPI_Status *status)

Fortran Syntax

USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_IMPROBE(SOURCE, TAG, COMM, FLAG, MESSAGE, STATUS, IERROR)


	LOGICAL			FLAG

	INTEGER			SOURCE, TAG, COMM, MESSAGE

	INTEGER			STATUS(MPI_STATUS_SIZE), IERROR

Fortran 2008 Syntax

USE mpi_f08
MPI_Improbe(source, tag, comm, flag, message, status, ierror)

	INTEGER, INTENT(IN) :: source, tag
	TYPE(MPI_Comm), INTENT(IN) :: comm
	INTEGER, INTENT(OUT) :: flag
	TYPE(MPI_Message), INTENT(OUT) :: message
	TYPE(MPI_Status) :: status
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

	source		Source rank or MPI_ANY_SOURCE (integer).
	tag		Tag value or MPI_ANY_TAG (integer).
	comm		Communicator (handle).

OUTPUT PARAMETERS

	flag		Flag (logical).
	message		Message (handle).
	status		Status object (status).
	IERROR		Fortran only: Error status (integer).

Like MPI_Probe and MPI_Iprobe, the MPI_Mprobe and MPI_Improbe operations allow incoming messages to be queried without actually receiving them, except that MPI_Mprobe and MPI_Improbe provide a mechanism to receive the specific message that was matched regardless of other intervening probe or receive operations. This gives the application an opportunity to decide how to receive the message, based on the information returned by the probe. In particular, the application may allocate memory for the receive buffer according to the length of the probed message.

A matching probe with MPI_PROC_NULL as source returns flag = true, message = MPI_MESSAGE_NO_PROC, and the status object returns source = MPI_PROC_NULL, tag = MPI_ANY_TAG, and count = 0.

MPI_Iprobe returns a true value in flag if a message has been matched and can be received by passing the message handle to the MPI_Mrecv or MPI_Imrecv functions, provided the source was not MPI_PROC_NULL.

NOTE

This is an MPI-3 function and has no C++ binding.

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.

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.