Buổi 4: MÔ HÌnh mpi master/worker
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Buổi 4: MÔ HÌNH MPI MASTER/WORKERVí dụ: một chương trình MPI theo mô hình Master/Worker để tính trung bình các số thực. /* * http://www.lam-mpi.org/tutorials/ * * Homework: Manager/worker (calculate an average in parallel) * * Mail questions regarding tutorial material to lam at lam dash mpi dot org */ #include #include #include { int source, dest; int total, workers; double avg; int *data, *sum, mysum; int rank, size; int i, len = 100, tag = 200; MPI_Request *request; MPI_Init(&argc, &argv); MPI_Comm_rank(MPI_COMM_WORLD, &rank); MPI_Comm_size(MPI_COMM_WORLD, &size);
if (rank == 0) { /* Allocate and initialize the data */ workers = size - 1; data = malloc(sizeof(int) * workers * len); sum = malloc(sizeof(int) * workers); request = malloc(sizeof(MPI_Request) * workers);
data[i] = i; /* Send the data to each of the other processes */
dest = i + 1; /* Send the data to worker dest, use a non-blocking send and use request[i] */ MPI_Isend(data + i * len, len, MPI_INT, dest, tag + dest, MPI_COMM_WORLD, &request[i]); }
/* Receive the results */ for (i = 0; i < workers; ++i) { source = i + 1; /* Do a non-blocking receive from source, placing the incoming number in the sum array, again use request[i] */ MPI_Irecv(sum + i, 1, MPI_INT, source, tag + source, MPI_COMM_WORLD, &request[i]); }
MPI_Waitall(workers, request, MPI_STATUSES_IGNORE); total = 0; for (i = 0; i < workers; ++i) total += sum[i];
printf("The average is %lf\n", avg); free(data); free(sum); free(request); }
else { data = malloc(sizeof(int) * len); mysum = 0; /* Receive the data from the manager */ MPI_Recv(data, len, MPI_INT, 0, tag + rank, MPI_COMM_WORLD, MPI_STATUS_IGNORE); for (i = 0; i < len; ++i) mysum += data[i]; /* Send my sum back to the manager */ MPI_Send(&mysum, 1, MPI_INT, 0, tag + rank, MPI_COMM_WORLD); free(data); }
return 0; } tải về 16.78 Kb. Chia sẻ với bạn bè của bạn:
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