thread_split_pthreads.c

#include <mpi.h>#include <pthread.h>#define n 2int thread_id[n];MPI_Comm split_comm[n];pthread_t thread[n];void *worker(void *arg){    int i = *((int *) arg), j = i;    MPI_Comm comm = split_comm[i];    MPI_Allreduce(MPI_IN_PLACE, &j, 1, MPI_INT, MPI_SUM, comm);    printf("Thread %d: allreduce returned %d\n", i, j);}int main(){    MPI_Info info;    int i, provided;    char s[16];    MPI_Init_thread(NULL, NULL, MPI_THREAD_MULTIPLE, &provided);    MPI_Info_create(&info);    for (i = 0; i < n; i++) {        MPI_Comm_dup(MPI_COMM_WORLD, &split_comm[i]);        sprintf(s, "%d", i);        MPI_Info_set(info, "thread_id", s);        MPI_Comm_set_info(split_comm[i], info);        thread_id[i] = i;        pthread_create(&thread[i], NULL, worker, (void *) &thread_id[i]);    }    for (i = 0; i < n; i++) {        pthread_join(thread[i], NULL);    }    MPI_Info_free(&info);    MPI_Finalize();}

See Also

thread_split_omp_for.c

thread_split_omp_task.c

Threading Runtimes Support