req_wait.c

MPI stands for the Message Passing Interface. Written by the MPI Forum (a large committee comprising

        for( completed = i = 0; i < count; i++ ) {
            request = *rptr++;
            if (request->req_complete == true) {
                completed++;
            }
        }
#endif  /* OMPI_HAVE_THREAD_SUPPORT */
        while( completed != count ) {
            /* check number of pending requests */
            size_t start = ompi_request_completed;
            size_t pending = count - completed;
            /*
             * wait until at least pending requests complete
             */
            while (pending > ompi_request_completed - start) {
                opal_condition_wait(&ompi_request_cond, &ompi_request_lock);
            }
            /*
             * confirm that all pending operations have completed.
             */
            rptr = requests;
            for( completed = i = 0; i < count; i++ ) {
                request = *rptr++;
                if (request->req_complete == true) {
                    completed++;
                }
            }
        }
        ompi_request_waiting--;
        OPAL_THREAD_UNLOCK(&ompi_request_lock);
    }

    rptr = requests;
    if (MPI_STATUSES_IGNORE != statuses) {
        /* fill out status and free request if required */
        for( i = 0; i < count; i++, rptr++ ) {
            request = *rptr;
            assert( true == request->req_complete );
            if (OMPI_REQUEST_GEN == request->req_type) {
                ompi_grequest_invoke_query(request, &request->req_status);
            }
            if( request->req_state == OMPI_REQUEST_INACTIVE ) {
                statuses[i] = ompi_status_empty;
            } else {
                statuses[i] = request->req_status;
            }
            if( request->req_persistent ) {
                request->req_state = OMPI_REQUEST_INACTIVE;
            } else {
                /* Only free the request if there is no error on it */
                if (MPI_SUCCESS == request->req_status.MPI_ERROR) {
                    /* If there's an error while freeing the request,
                       assume that the request is still there.
                       Otherwise, Bad Things will happen later! */
                    int tmp = ompi_request_free(rptr);
                    if (OMPI_SUCCESS != tmp) {
                        mpi_error = tmp;
                    }
                }
            }
            if( statuses[i].MPI_ERROR != OMPI_SUCCESS) {
                mpi_error = MPI_ERR_IN_STATUS;
            }
        }
    } else {
        /* free request if required */
        for( i = 0; i < count; i++, rptr++ ) {
            int rc;
            request = *rptr;

            assert( true == request->req_complete );
            /* Per note above, we have to call gen request query_fn
               even if STATUSES_IGNORE was provided */
            if (OMPI_REQUEST_GEN == request->req_type) {
                rc = ompi_grequest_invoke_query(request, &request->req_status);
            }
            if( request->req_state == OMPI_REQUEST_INACTIVE ) {
                rc = ompi_status_empty.MPI_ERROR;
            } else {
	        rc = request->req_status.MPI_ERROR;
            }
            if( request->req_persistent ) {
                request->req_state = OMPI_REQUEST_INACTIVE;
            } else if (MPI_SUCCESS == rc) {
                /* Only free the request if there is no error on it */
	        int tmp = ompi_request_free(rptr);
                if (OMPI_SUCCESS != tmp) {
                    mpi_error = tmp;
                }
            }
            if( rc != OMPI_SUCCESS) {
	        mpi_error = rc;
            }
	}
    }
    return mpi_error;
}


int ompi_request_wait_some(
    size_t count,
    ompi_request_t ** requests,
    int * outcount,
    int * indices,
    ompi_status_public_t * statuses)
{
#if OMPI_ENABLE_PROGRESS_THREADS
    int c;
#endif
    size_t i, num_requests_null_inactive=0, num_requests_done=0;
    int rc = MPI_SUCCESS;
    ompi_request_t **rptr=NULL;
    ompi_request_t *request=NULL;

    *outcount = 0;
    for (i = 0; i < count; i++){
        indices[i] = 0;
    }

#if OMPI_ENABLE_PROGRESS_THREADS
    /* poll for completion */
    OPAL_THREAD_ADD32(&opal_progress_thread_count,1);
    for (c = 0; c < opal_progress_spin_count; c++) {
        rptr = requests;
        num_requests_null_inactive = 0;
        num_requests_done = 0;
        for (i = 0; i < count; i++, rptr++) {
            request = *rptr;
            /*
             * Check for null or completed persistent request.
             * For MPI_REQUEST_NULL, the req_state is always OMPI_REQUEST_INACTIVE
             */
            if (request->req_state == OMPI_REQUEST_INACTIVE ) {
                num_requests_null_inactive++;
                continue;
            }
            if (true == request->req_complete) {
                indices[i] = 1;
                num_requests_done++;
            }
        }
        if (num_requests_null_inactive == count ||
            num_requests_done > 0) {
            OPAL_THREAD_ADD32(&opal_progress_thread_count,-1);
            goto finished;
        }
        opal_progress();
    }
    OPAL_THREAD_ADD32(&opal_progress_thread_count,-1);
#endif

    /*
     * We only get here when outcount still is 0.
     * give up and sleep until completion
     */
    OPAL_THREAD_LOCK(&ompi_request_lock);
    ompi_request_waiting++;
    do {
        rptr = requests;
        num_requests_null_inactive = 0;
        num_requests_done = 0;
        for (i = 0; i < count; i++, rptr++) {
            request = *rptr;
            /*
             * Check for null or completed persistent request.
             * For MPI_REQUEST_NULL, the req_state is always OMPI_REQUEST_INACTIVE.
             */
            if( request->req_state == OMPI_REQUEST_INACTIVE ) {
                num_requests_null_inactive++;
                continue;
            }
            if (request->req_complete == true) {
                indices[i] = 1;
                num_requests_done++;
            }
        }
        if (num_requests_null_inactive == count ||
            num_requests_done > 0)
            break;
        opal_condition_wait(&ompi_request_cond, &ompi_request_lock);
    } while (1);
    ompi_request_waiting--;
    OPAL_THREAD_UNLOCK(&ompi_request_lock);

#if OMPI_ENABLE_PROGRESS_THREADS
finished:
#endif  /* OMPI_ENABLE_PROGRESS_THREADS */

    if(num_requests_null_inactive == count) {
        *outcount = MPI_UNDEFINED;
    } else {
        /*
         * Compress the index array.
         */
        for (i = 0, num_requests_done = 0; i < count; i++) {
            if (0 != indices[i]) {
                indices[num_requests_done++] = i;
            }
        }

        *outcount = num_requests_done;

        for (i = 0; i < num_requests_done; i++) {
            request = requests[indices[i]];
            assert( true == request->req_complete );
            /* return status */
            /* Per note above, we have to call gen request query_fn even
               if STATUS_IGNORE was provided */
            if (OMPI_REQUEST_GEN == request->req_type) {
                ompi_grequest_invoke_query(request, &request->req_status);
            }
            if (MPI_STATUSES_IGNORE != statuses) {
                statuses[i] = request->req_status;
            }

            if (MPI_SUCCESS != request->req_status.MPI_ERROR) {
                rc = MPI_ERR_IN_STATUS;
            }

            if( request->req_persistent ) {
                request->req_state = OMPI_REQUEST_INACTIVE;
            } else {
                /* Only free the request if there was no error */
                if (MPI_SUCCESS == request->req_status.MPI_ERROR) {
                    int tmp;
                    tmp = ompi_request_free(&(requests[indices[i]]));
                    if (OMPI_SUCCESS != tmp) {
                        return tmp;
                    }
                }
            }
        }
    }
    return rc;
}