Question

int proc_cnt, rank;

MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &proc_cnt);

if (rank == 0) {
    std::vector<int> segment_ids = read_segment_ids(argv[kParDataIx]);
    std::map<int, ParameterSet> computed_par_sets;

    int buf_send[kBufMsToSlSize];
    double buf_recv[kBufSlToMsSize];
    MPI_Status status;

    int curr_segment_ix = 0;
    int recv_par_sets = 0;

    //inits workers
    for (int i = 1; i < proc_cnt; i++) {
        buf_send[0] = segment_ids[curr_segment_ix++];
        MPI_Send(
                buf_send, kBufMsToSlSize * sizeof (int), MPI_INT,
                i, 0, MPI_COMM_WORLD);
    }

    //sends slaves what to do and receives answers
    while(recv_par_sets < segment_ids.size()) {
        //receives answer
        MPI_Recv(buf_recv, kBufSlToMsSize * sizeof (double), MPI_DOUBLE, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
        recv_par_sets++;

        if (curr_segment_ix < segment_ids.size()) {
            //there are still segments to process
            buf_send[0] = segment_ids[curr_segment_ix++];
        } else {
            //there is no segment to process, sends to slave termination char
            buf_send[0] = -1;
        }
        //sends back to source which segment to process as next
        MPI_Send(
                buf_send, kBufMsToSlSize * sizeof (int), MPI_INT,
                status.MPI_SOURCE, 0, MPI_COMM_WORLD);  

        std::pair<int,ParameterSet> computed_seg_par_set = convert_array_to_seg_par_set(buf_recv);
        computed_par_sets.insert(computed_seg_par_set);
    }

    print_parameter_sets(computed_par_sets);
    std::cout << "[Master] was termianted" << std::endl;
} else {

    int bufToSl[kBufMsToSlSize];
    double bufToMs[kBufSlToMsSize];

    Bounds bounds = read_bounds_file(argv[kParBoundsIx]);
    Config config = read_config_file(kConfigFileName);

    while (true) {
        MPI_Recv(bufToSl, kBufMsToSlSize * sizeof (int), MPI_INT, 0, MPI_ANY_TAG, MPI_COMM_WORLD, MPI_STATUSES_IGNORE);
        int segment_id = bufToSl[0];

        if (segment_id == -1) {
            //termination character was found
            break;
        }

        Segment segment = read_segment(argv[kParDataIx], segment_id);
        std::map<int, Segment> segment_map;
        segment_map.insert(std::pair<int, Segment>(segment.GetId(), segment));

        SimplexComputer simplex_computer(segment_map, bounds, config);
        ParameterSet par_set = simplex_computer.ComputeSegment(&segment);
        convert_seg_par_set_to_array(segment_id, par_set, bufToMs);

        MPI_Send(
                bufToMs, kBufSlToMsSize * sizeof (double), MPI_DOUBLE,
                0, 0, MPI_COMM_WORLD);
    }
    std::cout << "[SLAVE] " << rank << " was terminated" << std::endl;

}

MPI_Finalize();

我只是不明白。当我尝试使用mpirun并将进程计数设置为5来运行时，所有进程都完成，控制输出表明主服务器或从服务器已终止打印，但最后有这样的声明：

mpirun注意到节点Jan-MacBook上的PID 1534进程等级0退出信号6（中止陷阱：6）。

我做错了什么？提前谢谢你们。

Answer 1

根据Send和Recv定义，第二个参数 count 是您要发送或接收的元素数。然后将这些元素的数据类型指定为两个调用的第三个参数：

int MPI_Send(const void *buf, int count, MPI_Datatype datatype, int dest, int tag, MPI_Comm comm)

和Recv一样：

int MPI_Recv(void *buf, int count, MPI_Datatype datatype, int source, int tag, MPI_Comm comm, MPI_Status *status)

您可以在此处找到自己的答案：Send和Recv。

希望它有所帮助。

MPI - mpirun注意到这个过程......在信号6上退出

1 个答案: