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1// RUN: %libomp-compile2// RUN: %libomp-run3// RUN: env KMP_AFFINITY=none %libomp-run4// REQUIRES: linux5 6// Check if forked child process resets affinity properly by restricting7// child's affinity to a subset of the parent and then checking it after8// a parallel region9 10#define _GNU_SOURCE11#include "libomp_test_affinity.h"12#include <omp.h>13#include <stdio.h>14#include <stdlib.h>15#include <sys/wait.h>16#include <sys/types.h>17#include <unistd.h>18 19// Set the affinity mask of the calling thread to a proper subset of the20// original affinity mask, specifically, one processor less.21void set_subset_affinity(affinity_mask_t *mask) {22 int cpu;23 affinity_mask_t *original_mask = affinity_mask_alloc();24 affinity_mask_copy(original_mask, mask);25 // Find first processor to clear for subset mask26 for (cpu = 0; cpu <= AFFINITY_MAX_CPUS; ++cpu) {27 if (affinity_mask_isset(original_mask, cpu)) {28 affinity_mask_clr(mask, cpu);29 break;30 }31 }32 affinity_mask_free(original_mask);33 set_thread_affinity(mask);34}35 36int main(int argc, char **argv) {37 char buf[1024] = {0};38 char *other_buf;39 size_t n;40 int child_exit_status, exit_status;41 affinity_mask_t *mask = affinity_mask_alloc();42 get_thread_affinity(mask);43 n = affinity_mask_snprintf(buf, sizeof(buf), mask);44 printf("Orignal Mask: %s\n", buf);45 46 if (affinity_mask_count(mask) == 1) {47 printf("Only one processor in affinity mask, skipping test.\n");48 exit(EXIT_SUCCESS);49 }50 51 #pragma omp parallel52 {53 #pragma omp single54 printf("Hello! Thread %d executed single region in parent process\n",55 omp_get_thread_num());56 }57 58 pid_t pid = fork();59 if (pid < 0) {60 perror("fork()");61 exit(EXIT_FAILURE);62 }63 64 if (pid == 0) {65 // Let child set a new initial mask66 set_subset_affinity(mask);67 #pragma omp parallel68 {69 #pragma omp single70 printf("Hello! Thread %d executed single region in child process\n",71 omp_get_thread_num());72 }73 affinity_mask_t *new_mask = affinity_mask_alloc();74 get_thread_affinity(new_mask);75 if (!affinity_mask_equal(mask, new_mask)) {76 affinity_mask_snprintf(buf, sizeof(buf), mask);77 fprintf(stderr, "Original Mask = %s\n", buf);78 affinity_mask_snprintf(buf, sizeof(buf), new_mask);79 fprintf(stderr, "New Mask = %s\n", buf);80 affinity_mask_free(new_mask);81 fprintf(stderr, "Child affinity mask did not reset properly\n");82 exit(EXIT_FAILURE);83 }84 affinity_mask_free(new_mask);85 exit_status = EXIT_SUCCESS;86 } else {87 pid_t child_pid = pid;88 pid = wait(&child_exit_status);89 if (pid == -1) {90 perror("wait()");91 exit(EXIT_FAILURE);92 }93 if (WIFEXITED(child_exit_status)) {94 exit_status = WEXITSTATUS(child_exit_status);95 } else {96 exit_status = EXIT_FAILURE;97 }98 }99 100 affinity_mask_free(mask);101 return exit_status;102}103