Hello all!
Im with OMPI 4.0.1 and I have a strange behaviour (or at least, unexpected)
with some non-blocking sending calls: MPI_Isend and MPI_Ibcast. I really need
asyncronous sending so I dont use MPI_Wait after the send call (MPI_Isend or
MPI_Ibcast); insted of this I check "on demand" with MPI_Test to verify if
sending its or not complete. Test Im doing it sends just an int value. Here
some code (with MPI_Ibcast):
***SENDER***
//Note that It use an intercommunicator
MPI_Ibcast(&send_some_int_data, 1, MPI_INT, MPI_ROOT, mpi_intercomm,
&request_sender);
//MPI_Wait(&request_sender, MPI_STATUS_IGNORE); <-- I dont want this
***RECEIVER***
MPI_Ibcast(&recv_some_int_data, 1, MPI_INT, 0, parentcomm, &request_receiver);
MPI_Wait(&request_receiver, MPI_STATUS_IGNORE);
***TEST RECEPTION (same sender instance program)***
void test_reception() {
int request_complete;
MPI_Test(&request_sender, &request_complete, MPI_STATUS_IGNORE);
if (request_complete) {
...
} else {
...
}
}
But when I invoke this test function after some time has elapsed since I sent,
the request isnt complete and i have to invoque this test function again and
againg... x (variable) times, until it finally its completed. Its just an int
it was sended, just that (all on a local machine); has no sense such delay. The
request should be completed on the first function test invocation.
If, instead of this, I uncomment the unwanted MPI_Wait (i.e. doing it like a
synchronous request), it completes immediately, like expected.
If I send with MPI_Isend I get the same behaviour.
I dont understand whats is going on. Any help will be very appreciated.
Regards.
Martín
