fork-plus-threads.c revision 1.1.1.2
1/* This testcase is part of GDB, the GNU debugger. 2 3 Copyright 2015-2016 Free Software Foundation, Inc. 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 17 18#include <assert.h> 19#include <pthread.h> 20#include <unistd.h> 21#include <stdio.h> 22#include <sys/types.h> 23#include <sys/wait.h> 24 25 26/* Number of times the main process forks. */ 27#define NFORKS 10 28 29/* Number of threads by each fork child. */ 30#define NTHREADS 10 31 32static void * 33thread_func (void *arg) 34{ 35 /* Empty. */ 36} 37 38static void 39fork_child (void) 40{ 41 pthread_t threads[NTHREADS]; 42 int i; 43 int ret; 44 45 for (i = 0; i < NTHREADS; i++) 46 { 47 ret = pthread_create (&threads[i], NULL, thread_func, NULL); 48 assert (ret == 0); 49 } 50 51 for (i = 0; i < NTHREADS; i++) 52 { 53 ret = pthread_join (threads[i], NULL); 54 assert (ret == 0); 55 } 56} 57 58int 59main (void) 60{ 61 pid_t childs[NFORKS]; 62 int i; 63 int status; 64 int num_exited = 0; 65 66 /* Don't run forever if the wait loop below gets stuck. */ 67 alarm (180); 68 69 for (i = 0; i < NFORKS; i++) 70 { 71 pid_t pid; 72 73 pid = fork (); 74 75 if (pid > 0) 76 { 77 /* Parent. */ 78 childs[i] = pid; 79 } 80 else if (pid == 0) 81 { 82 /* Child. */ 83 fork_child (); 84 return 0; 85 } 86 else 87 { 88 perror ("fork"); 89 return 1; 90 } 91 } 92 93 while (num_exited != NFORKS) 94 { 95 pid_t pid = wait (&status); 96 97 if (pid == -1) 98 { 99 perror ("wait"); 100 return 1; 101 } 102 103 if (WIFEXITED (status)) 104 { 105 num_exited++; 106 } 107 else 108 { 109 printf ("Hmm, unexpected wait status 0x%x from child %d\n", status, 110 pid); 111 } 112 } 113 114 return 0; 115} 116