通过MPI正常退出 [英] Gracefully exit with MPI

问题描述

如果Rdinput返回错误，我试图正常退出程序.

I'm trying to gracefully exit my program after if Rdinput returns an error.

#include <mpi.h>
#include <stdio.h>
#include <stdlib.h>

#define MASTER 0
#define Abort(x) MPI_Abort(MPI_COMM_WORLD, x)
#define Bcast(send_data, count, type) MPI_Bcast(send_data, count, type, MASTER, GROUP) //root --> MASTER
#define Finalize() MPI_Finalize()

int main(int argc, char **argv){

  //Code

  if( rank == MASTER ) {
    time (&start);
    printf("Initialized at %s\n", ctime (&start) );      
    //Read file
    error = RdInput();
  }

  Bcast(&error, 1, INT); Wait();

  if( error = 1 ) MPI_Abort(1);

  //Code

  Finalize();
}

程序输出:

mpirun -np 2 code.x 
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD 
with errorcode 1.

NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.
--------------------------------------------------------------------------
Initialized at Wed May 30 11:34:46 2012
Error [RdInput]: The file "input.mga" is not available!
--------------------------------------------------------------------------
mpirun has exited due to process rank 0 with PID 7369 on
node einstein exiting improperly. There are two reasons this could occur:

//More error message.

我该怎么做才能在不打印此巨大错误消息的情况下正常退出MPI程序?

What can I do to gracefully exit an MPI program without printing this huge error message?

推荐答案

如果您的代码中包含以下逻辑:

If you have this logic in your code:

Bcast(&error, 1, INT);
if( error = 1 ) MPI_Abort(1); 

那您就快完成了(尽管在广播后不需要任何等待).您发现的诀窍是MPI_Abort()不会 做到优美"；基本上，当发生严重错误时，可以以任何可能的方式关闭计算机.

then you're just about done (although you don't need any kind of wait after a broadcast). The trick, as you've discovered, is that MPI_Abort() does not do "graceful"; it basically is there to shut things down in whatever way possible when something's gone horribly wrong.

在这种情况下，由于现在每个人都同意广播后的错误代码，所以请妥善地结束程序:

In this case, since now everyone agrees on the error code after the broadcast, just do a graceful end of your program:

   MPI_Bcast(&error, 1, MPI_INT, MASTER, MPI_COMM_WORLD);
   if (error != 0) {
       if (rank == 0) {
           fprintf(stderr, "Error: Program terminated with error code %d\n", error);
       }
       MPI_Finalize();
       exit(error);
   } 

调用MPI_Finalize()并继续处理更多MPI内容是一个错误，但这不是您在这里所做的，所以您还可以.

It's an error to call MPI_Finalize() and keep on going with more MPI stuff, but that's not what you're doing here, so you're fine.

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