Developer Guide

  • 2021.1
  • 12/04/2020
  • Public Content
Contents

thread_split_omp_task.c

#include <mpi.h> #include <omp.h> #define n 2 MPI_Comm split_comm[n]; 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); } #pragma omp parallel num_threads(n) { #pragma omp task { int j = 1; MPI_Allreduce(MPI_IN_PLACE, &j, 1, MPI_INT, MPI_SUM, split_comm[1]); printf("OMP thread %d, logical thread %d: allreduce returned %d\n", omp_get_thread_num(), 1, j); } #pragma omp task { int j = 0; MPI_Allreduce(MPI_IN_PLACE, &j, 1, MPI_INT, MPI_SUM, split_comm[0]); printf("OMP thread %d, logical thread %d: allreduce returned %d\n", omp_get_thread_num(), 0, j); } } MPI_Info_free(&info); MPI_Finalize(); }
See Also

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