MPI_Imrecv − Non-blocking receive for a matched message
#include
<mpi.h>
int MPI_Imrecv(void *buf, int count,
MPI_Datatype type,
MPI_Message *message, MPI_Request *request) |
USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_IMRECV(BUF, COUNT, DATATYPE, MESSAGE, REQUEST,
IERROR)
<type> |
BUF(*) | |||
INTEGER |
COUNT, DATATYPE, MESSAGE, REQUEST, IERROR |
USE mpi_f08
MPI_Imrecv(buf, count, datatype,
message, request, ierror)
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: buf | |
INTEGER, INTENT(IN) :: count | |
TYPE(MPI_Datatype), INTENT(IN) :: datatype | |
TYPE(MPI_Message), INTENT(INOUT) :: message | |
TYPE(MPI_Request), INTENT(OUT) :: request | |
INTEGER, OPTIONAL, INTENT(OUT) :: ierror |
count |
Number of elements to receive (nonnegative integer). |
|||
datatype |
Datatype of each send buffer element (handle). |
|||
message |
Message (handle). |
buf |
Initial address of receive buffer (choice). |
|||
request |
Request (handle). |
|||
IERROR |
Fortran only: Error status (integer). |
The functions MPI_Mrecv and MPI_Imrecv receive messages that have been previously matched by a matching probe.
The request returned from MPI_Imrecv can be used with any of the MPI_Test and MPI_Wait variants, like any non-blocking receive request.
If MPI_Imrecv is called with MPI_MESSAGE_NULL as the message argument, a call to one of the MPI_Test or MPI_Wait variants will return immediately with the status object set to source = MPI_PROC_NULL, tag = MPI_ANY_TAG, and count = 0, as if a receive from MPI_PROC_NULL was issued.
If reception of a matched message is started with MPI_Imrecv, then it is possible to cancel the returned request with MPI_Cancel. If MPI_Cancel succeeds, the matched message must be found by a subsequent message probe (MPI_Probe, MPI_Iprobe, MPI_Mprobe, or MPI_Improbe), received by a subsequent receive operation or canceled by the sender.
Note, however, that is it possible for the cancellation of operations initiated with MPI_Imrecv to fail. An example of a failing case is when canceling the matched message receive would violate MPI message ordering rules (e.g., if another message matching the same message signature has matched -- and possible received -- before this MPI_Imrecv is canceled).
This is an MPI-3 function and has no C++ binding.
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.
MPI_Mprobe
MPI_Improbe
MPI_Probe
MPI_Iprobe
MPI_Imrecv
MPI_Cancel