call MPI_WAIT(request, status, ierr) 
                 |       |       |
              request    |     error
              handle     |
		      status



call MPI_TEST(request, flag, status, ierr) 
                 |       |      |      |
              request    |   status    |
              handle     |           error
		     true if
		     operation
		     completed

			 

call MPI_WAITALL(count, requests, statuses, ierr)
                   |       |          |       |
                 list   array of   array of   |
                length  requests   statuses   |
					    error