nptl/tst-fork2.c

   1 /* Copyright (C) 2002-2019 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Roland McGrath <roland@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <pthread.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <sys/wait.h>
  25
  26
  27 static pid_t initial_pid;
  28
  29
  30 static void *
  31 tf (void *arg)
  32 {
  33   if (getppid () != initial_pid)
  34     {
  35       printf ("getppid in thread returned %ld, expected %ld\n",
  36               (long int) getppid (), (long int) initial_pid);
  37       return (void *) -1;
  38     }
  39
  40   return NULL;
  41 }
  42
  43
  44 int
  45 main (void)
  46 {
  47   initial_pid = getpid ();
  48
  49   pid_t child = fork ();
  50   if (child == 0)
  51     {
  52       if (getppid () != initial_pid)
  53         {
  54           printf ("first getppid returned %ld, expected %ld\n",
  55                   (long int) getppid (), (long int) initial_pid);
  56           exit (1);
  57         }
  58
  59       pthread_t th;
  60       if (pthread_create (&th, NULL, tf, NULL) != 0)
  61         {
  62           puts ("pthread_create failed");
  63           exit (1);
  64         }
  65
  66       void *result;
  67       if (pthread_join (th, &result) != 0)
  68         {
  69           puts ("pthread_join failed");
  70           exit  (1);
  71         }
  72
  73       exit (result == NULL ? 0 : 1);
  74     }
  75   else if (child == -1)
  76     {
  77       puts ("initial fork failed");
  78       return 1;
  79     }
  80
  81   int status;
  82   if (TEMP_FAILURE_RETRY (waitpid (child, &status, 0)) != child)
  83     {
  84       printf ("waitpid failed: %m\n");
  85       return 1;
  86     }
  87
  88   return status;
  89 }