posix/tst-vfork1.c

   1 /* Test for vfork functions.
   2    Copyright (C) 2004 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <sys/types.h>
  26 #include <sys/wait.h>
  27
  28 /* This test relies on non-POSIX functionality since the child
  29    processes call write and getpid.  */
  30 static int
  31 do_test (void)
  32 {
  33   int result = 0;
  34   int fd[2];
  35
  36   if (pipe (fd) == -1)
  37     {
  38       puts ("pipe failed");
  39       return 1;
  40     }
  41
  42   /* First vfork() without previous getpid().  */
  43   pid_t p1;
  44   if ((p1 = vfork ()) == 0)
  45     {
  46       pid_t p = getpid ();
  47       _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
  48     }
  49   else if (p1 == -1)
  50     {
  51       puts ("1st vfork failed");
  52       result = 1;
  53     }
  54
  55   pid_t p2 = 0;
  56   if (TEMP_FAILURE_RETRY (read (fd[0], &p2, sizeof (pid_t))) != sizeof (pid_t))
  57     {
  58       puts ("1st read failed");
  59       result = 1;
  60     }
  61   int r;
  62   if (TEMP_FAILURE_RETRY (waitpid (p1, &r, 0)) != p1)
  63     {
  64       puts ("1st waitpid failed");
  65       result = 1;
  66     }
  67   else if (r != 0)
  68     {
  69       puts ("write in 1st child failed");
  70       result = 1;
  71     }
  72
  73   /* Main process' ID.  */
  74   pid_t p0 = getpid ();
  75
  76   /* vfork() again, but after a getpid() in the main process.  */
  77   pid_t p3;
  78   if ((p3 = vfork ()) == 0)
  79     {
  80       pid_t p = getpid ();
  81       _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
  82     }
  83   else if (p1 == -1)
  84     {
  85       puts ("2nd vfork failed");
  86       result = 1;
  87     }
  88
  89   pid_t p4;
  90   if (TEMP_FAILURE_RETRY (read (fd[0], &p4, sizeof (pid_t))) != sizeof (pid_t))
  91     {
  92       puts ("2nd read failed");
  93       result = 1;
  94     }
  95   if (TEMP_FAILURE_RETRY (waitpid (p3, &r, 0)) != p3)
  96     {
  97       puts ("2nd waitpid failed");
  98       result = 1;
  99     }
 100   else if (r != 0)
 101     {
 102       puts ("write in 2nd child failed");
 103       result = 1;
 104     }
 105
 106   /* And getpid in the main process again.  */
 107   pid_t p5 = getpid ();
 108
 109   /* Analysis of the results.  */
 110   if (p0 != p5)
 111     {
 112       printf ("p0(%ld) != p5(%ld)\n", (long int) p0, (long int) p5);
 113       result = 1;
 114     }
 115
 116   if (p0 == p1)
 117     {
 118       printf ("p0(%ld) == p1(%ld)\n", (long int) p0, (long int) p1);
 119       result = 1;
 120     }
 121
 122   if (p1 != p2)
 123     {
 124       printf ("p1(%ld) != p2(%ld)\n", (long int) p1, (long int) p2);
 125       result = 1;
 126     }
 127
 128   if (p0 == p3)
 129     {
 130       printf ("p0(%ld) == p3(%ld)\n", (long int) p0, (long int) p3);
 131       result = 1;
 132     }
 133
 134   if (p3 != p4)
 135     {
 136       printf ("p3(%ld) != p4(%ld)\n", (long int) p3, (long int) p4);
 137       result = 1;
 138     }
 139
 140   close (fd[0]);
 141   close (fd[1]);
 142
 143   if (result == 0)
 144     puts ("All OK");
 145
 146   return result;
 147 }
 148
 149 #define TEST_FUNCTION do_test ()
 150 #include "../test-skeleton.c"