gdb/testsuite/gdb.threads/fork-plus-threads.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2015-2017 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
  32 static void *
  33 thread_func (void *arg)
  34 {
  35   /* Empty.  */
  36 }
  37
  38 static void
  39 fork_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
  58 int
  59 main (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 }