如何使用MPI_Abort（）终止其他处理器

Question

In MPI, MPI_Abort() is mostly intended for aborting abnormal behaviors. In my program below, at each iteration the ROOT process checks a condition while the remaining processors wait at the MPI_Barrier to receive the data for the next iteration. Thus, if the threshold is met, I want the root to terminate the entire loop and also other processors should leave the loop and terminate . My question is: Does it make sense to use MPI_Abort() so that processors who are waiting in the barrier will terminate?

void kmeans() {

    do{
        // Step1: ROOT Broadcast the K centroids.
        MPI_Bcast(&cluster_centroids, N, MPI_FLOAT, ROOT, MPI_COMM_WORLD);
        MPI_Barrier(MPI_COMM_WORLD);

        // Step2: Calculate the distances.
        points_assignment(data, cluster_center);

        // Step3: Update cluster centroid (Locally at each processor)
        update_centroids_locally();

        if(Rank == ROOT){
            // Step4: ROOT checks the threshold
            Flag = check_threshold(cluster_center);

            if(Flag == 1){
                // MPI_Abort(MPI_COMM_WORLD,0);
                break;
            }else{
                continue;
            }
        }

    } while(1);

}

Answer 1

To avoid the use of MPI_Abort , I can think two options for termination:

1) The simple one: each time broadcast a termination flag and each process will continue or stop based on that flag.

2) You could use two MPI_IBcast and MPI_Waitany . With the one MPI_IBcast you will broadcast your cluster_centroids and with the other one you will broadcast a termination flag. Each time you will check wich broadcast has been complete and based on that, each process will decide to continue or stop.