sysdeps/pthread/tst-fork2.c

   1 /* Copyright (C) 2002-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <pthread.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <sys/wait.h>
  24
  25
  26 static pid_t initial_pid;
  27
  28
  29 static void *
  30 tf (void *arg)
  31 {
  32   if (getppid () != initial_pid)
  33     {
  34       printf ("getppid in thread returned %ld, expected %ld\n",
  35               (long int) getppid (), (long int) initial_pid);
  36       return (void *) -1;
  37     }
  38
  39   return NULL;
  40 }
  41
  42
  43 int
  44 main (void)
  45 {
  46   initial_pid = getpid ();
  47
  48   pid_t child = fork ();
  49   if (child == 0)
  50     {
  51       if (getppid () != initial_pid)
  52         {
  53           printf ("first getppid returned %ld, expected %ld\n",
  54                   (long int) getppid (), (long int) initial_pid);
  55           exit (1);
  56         }
  57
  58       pthread_t th;
  59       if (pthread_create (&th, NULL, tf, NULL) != 0)
  60         {
  61           puts ("pthread_create failed");
  62           exit (1);
  63         }
  64
  65       void *result;
  66       if (pthread_join (th, &result) != 0)
  67         {
  68           puts ("pthread_join failed");
  69           exit  (1);
  70         }
  71
  72       exit (result == NULL ? 0 : 1);
  73     }
  74   else if (child == -1)
  75     {
  76       puts ("initial fork failed");
  77       return 1;
  78     }
  79
  80   int status;
  81   if (TEMP_FAILURE_RETRY (waitpid (child, &status, 0)) != child)
  82     {
  83       printf ("waitpid failed: %m\n");
  84       return 1;
  85     }
  86
  87   return status;
  88 }