none/tests/pth_atfork1.c

   1 /* Tests for fork in multi-threaded environment.
   2    Copyright (C) 2000 Free Software Foundation, Inc.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <stdlib.h>
  22 #include <pthread.h>
  23 #include <unistd.h>
  24 #include <sys/wait.h>
  25 #include <stdio.h>
  26 #include <string.h>  /* strerror */
  27
  28 static void error (int status, int errnum, char* msg)
  29 {
  30    fprintf(stderr, "%s%s%s\n",
  31            msg,
  32            errnum ? ": " : "",
  33            errnum ? strerror(errnum) : "");
  34    if (errnum)
  35       exit(errnum);
  36 }
  37
  38 enum
  39 {
  40   PREPARE_BIT = 1,
  41   PARENT_BIT = 2,
  42   CHILD_BIT = 4
  43 };
  44
  45 static int var;
  46
  47 static void
  48 prepare (void)
  49 {
  50   var |= PREPARE_BIT;
  51 }
  52
  53 static void
  54 parent (void)
  55 {
  56   var |= PARENT_BIT;
  57 }
  58
  59 static void
  60 child (void)
  61 {
  62   var |= CHILD_BIT;
  63 }
  64
  65
  66 static void *thread (void *arg);
  67
  68
  69 int
  70 main (void)
  71 {
  72   pthread_t th;
  73   void *res;
  74
  75   pthread_atfork (prepare, parent, child);
  76
  77   if (pthread_create (&th, NULL, thread, NULL) != 0)
  78     error (EXIT_FAILURE, 0, "cannot create thread");
  79
  80   pthread_join (th, &res);
  81
  82   if ( ( int ) ( long int ) res != 0 )
  83       error(EXIT_FAILURE, 0, "pthread_join res != 0" );
  84
  85   printf ( "all ok\n" );
  86   return 0;
  87 }
  88
  89
  90 static void *
  91 thread (void *arg)
  92 {
  93   int status;
  94   pid_t pid;
  95
  96   pid = fork ();
  97   if (pid == 0)
  98     {
  99       /* We check whether the `prepare' and `child' function ran.  */
 100       exit (var != (PREPARE_BIT | CHILD_BIT));
 101     }
 102   else if (pid == (pid_t) -1)
 103     error (EXIT_FAILURE, errno, "cannot fork");
 104
 105   if (waitpid (pid, &status, 0) != pid)
 106     error (EXIT_FAILURE, errno, "wrong child");
 107
 108   if (WTERMSIG (status) != 0)
 109     error (EXIT_FAILURE, 0, "Child terminated incorrectly");
 110   status = WEXITSTATUS (status);
 111
 112   if (status == 0)
 113     status = var != (PREPARE_BIT | PARENT_BIT);
 114
 115   return (void *) (long int) status;
 116 }