MPI实现在两次传递后停止
MPI实现在两次传递后停止
提问于 2018-10-16 01:40:21
我对MPI比较陌生，所以我不确定为什么这段代码不能像预期的那样工作。这个想法是将一个整数传递给一个随机节点，然后递减它，直到它达到0。当我尝试运行它时，它传递了两次整数并停止。有人能给我指个方向吗？谢谢!
if (rank == 0)
{
potato = rand() % 100 + size; // generate a random number between the number of processors and 100
sendTo = rand() % (size - 1) + 1; // generate a number (not 0) to represent the process to send the potato to
MPI_Send(&potato, 1, MPI_INT, sendTo, 0, MPI_COMM_WORLD); // send the potato
}
else // any process other than 0
{
MPI_Recv(&potato, 1, MPI_INT, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, MPI_STATUS_IGNORE); //receive potato
if (potato == -1) // check for termination int
return;
--potato; // decrement potato
if (potato != 0)
{
do
{
sendTo = rand() % (size - 1) + 1; // send to a process 1 through size - 1
} while (sendTo == rank || sendTo == 0); // make sure it won't send the potato to itself or 0
printf("Node %d has the potato, passing to node %d.\n", rank, sendTo);
MPI_Send(&potato, 1, MPI_INT, sendTo, 0, MPI_COMM_WORLD);
}
else // potato == 0
{
printf("Node %d is it, game over.\n", rank);
potato = -1;
for (int i = 1; i < size; ++rank) // send termination message
MPI_Send(&potato, 1, MPI_INT, i, 0, MPI_COMM_WORLD);
}
}输出：
Potato: 44
Node 3 has the potato, Passing to node 2.
Node 2 has the potato, Passing to node 3.回答 1
Stack Overflow用户
回答已采纳
发布于 2018-10-16 03:42:41
您的代码缺少某些循环。在您的示例中，为了让节点3第二次接收帕托，必须再次调用MPI_Recv。
if (rank == 0)
{
potato = rand() % 100 + size; // generate a random number between the number of processors and 100
sendTo = rand() % (size - 1) + 1; // generate a number (not 0) to represent the process to send the potato to
MPI_Send(&potato, 1, MPI_INT, sendTo, 0, MPI_COMM_WORLD); // send the potato
}
else // any process other than 0
{
/* Here is the loop beginning, while patato is not -1, continue reading*/
while (1)
{
MPI_Recv(&potato, 1, MPI_INT, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, MPI_STATUS_IGNORE); //receive potato
if (potato == -1) // check for termination int
return;
--potato; // decrement potato
if (potato != 0)
{
do
{
sendTo = rand() % (size - 1) + 1; // send to a process 1 through size - 1
} while (sendTo == rank || sendTo == 0); // make sure it won't send the potato to itself or 0
printf("Node %d has the potato, passing to node %d.\n", rank, sendTo);
MPI_Send(&potato, 1, MPI_INT, sendTo, 0, MPI_COMM_WORLD);
}
else // potato == 0
{
printf("Node %d is it, game over.\n", rank);
potato = -1;
for (int i = 1; i < size; ++rank) // send termination message
MPI_Send(&potato, 1, MPI_INT, i, 0, MPI_COMM_WORLD);
}
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/52822089
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