Gracefully exit with MPI

Question

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

#include 
#include 
#include 

#define M         


        

Answer 1

If you have this logic in your code:

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

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.

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);
   } 

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.