我的 mpi 程序应该让等级 0 等待来自其他等级的消息，让它知道他们已准备好接收数据。此时，我的等级 0 将发送数据。不幸的是，它只捕获来自 1 级的“就绪”信号，我不知道为什么！
这是代码：
73 if(nrank == 0)
74 {
75 for(int at = 0; at < 2; at++)
76 {
77 for(int l = 0; l <= Lmax; l++)
78 {
79 for(int m = -l; m <= l; m++)
80 {
81 rank_rdy = 0;
82 /*****************
83 * prep the data *
84 *****************/
85 printf("----------------------------------------------\n");
86 printf("rank(0): generating data for (at, l, m) = (%i, %i, %i)\n", at, l, m);
87 info_space[0] = at;
88 info_space[1] = l;
89 info_space[2] = m;
90 read_d_grid(y_space, at, l, m);
91
92 /* wait for receiving signale */
93 printf("rank(0): waiting for ready signal ... \n");
94 rc = MPI_Recv(&rank_rdy, 1, MPI_INT, MPI_ANY_SOURCE, tag, MPI_COMM_WORLD, &status);
95 printf("rank(0): ready signal caught from rank %i\n", rank_rdy);
96 MPI_Send(info_space, 1, MPI_INT, rank_rdy, tag, MPI_COMM_WORLD);
97 }
98 }
99 }
100 }
101 else
102 {
103 int junk = 0;
104 rank_rdy = nrank;
105 tag = nrank;
106 MPI_Send(&rank_rdy, 1, MPI_INT, 0, tag, MPI_COMM_WORLD);
107
108 printf("rank(%i): ready signal sent\n", nrank);
109 // successful send
110 MPI_Recv(info_space, 1, MPI_INT, 0, tag, MPI_COMM_WORLD, &status);
111
112 for(int i = 0; i < 900000000; i++)
113 {
114 junk = junk + i;
115 }
116 printf("rank(%i): done spinning\n");
117 }
这个的输出是：
rank(0): inside getInputs: reading command line arguments
rank(2): inside getInputs: reading command line arguments
rank(3): inside getInputs: reading command line arguments
rank(1): inside getInputs: reading command line arguments
rank(0): inside read_r_grid(): reading meldrum.txt
----------------------------------------------
rank(0): generating data for (at, l, m) = (0, 0, 0)
rank(0): inside read_d_grid(y_space, 0, 0, 0)
rank(2): inside read_r_grid(): reading meldrum.txt
rank(3): inside read_r_grid(): reading meldrum.txt
rank(1): inside read_r_grid(): reading meldrum.txt
rank(0): waiting for ready signal ...
rank(2): ready signal sent
rank(3): ready signal sent
rank(1): ready signal sent
rank(0): ready signal caught from rank 1
----------------------------------------------
rank(0): generating data for (at, l, m) = (0, 1, -1)
rank(0): inside read_d_grid(y_space, 0, 1, -1)
rank(0): waiting for ready signal ...
现在，如果我将第 101 行更改为“else if(nrank == 2)”并将第 94 行更改为“2”而不是“MPI_ANY_SOURCE”，那么我根本不会收到任何信号捕获：
rank(0): inside getInputs: reading command line arguments
rank(3): inside getInputs: reading command line arguments
rank(2): inside getInputs: reading command line arguments
rank(1): inside getInputs: reading command line arguments
rank(0): inside read_r_grid(): reading meldrum.txt
rank(2): inside read_r_grid(): reading meldrum.txt
rank(3): inside read_r_grid(): reading meldrum.txt
rank(1): inside read_r_grid(): reading meldrum.txt
----------------------------------------------
rank(0): generating data for (at, l, m) = (0, 0, 0)
rank(0): inside read_d_grid(y_space, 0, 0, 0)
rank(0): waiting for ready signal ...
rank(2): ready signal sent
所以要知道 rank(0) 根本没有从 rank(1) 以外的任何人那里接收到任何信号。谁能看到为什么排名 1 以外的排名无法进入排名 0 的任何原因？