posix/tst-vfork2.c

   1 /* Test for vfork functions.
   2    Copyright (C) 2004-2019 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, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <signal.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <time.h>
  26 #include <unistd.h>
  27 #include <sys/time.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30
  31 int raise_fail;
  32
  33 static void
  34 alrm (int sig)
  35 {
  36   if (raise (SIGUSR1) < 0)
  37     raise_fail = 1;
  38 }
  39
  40 /* This test relies on non-POSIX functionality since the child
  41    processes call write, nanosleep and getpid.  */
  42 static int
  43 do_test (void)
  44 {
  45   int result = 0;
  46   int fd[2];
  47
  48   signal (SIGUSR1, SIG_IGN);
  49
  50   struct sigaction sa;
  51   sa.sa_handler = alrm;
  52   sigemptyset (&sa.sa_mask);
  53   sa.sa_flags = 0;
  54   if (sigaction (SIGALRM, &sa, NULL) < 0)
  55     {
  56       puts ("couldn't set up SIGALRM handler");
  57       return 1;
  58     }
  59
  60   if (pipe (fd) == -1)
  61     {
  62       puts ("pipe failed");
  63       return 1;
  64     }
  65
  66   struct itimerval it;
  67   it.it_value.tv_sec = 0;
  68   it.it_value.tv_usec = 200 * 1000;
  69   it.it_interval = it.it_value;
  70   if (setitimer (ITIMER_REAL, &it, NULL) < 0)
  71     {
  72       puts ("couldn't set up timer");
  73       return 1;
  74     }
  75
  76   /* First vfork() without previous getpid().  */
  77   pid_t p1;
  78   if ((p1 = vfork ()) == 0)
  79     {
  80       pid_t p = getpid ();
  81
  82       struct timespec ts;
  83       ts.tv_sec = 1;
  84       ts.tv_nsec = 0;
  85       TEMP_FAILURE_RETRY (nanosleep (&ts, &ts));
  86       _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
  87     }
  88   else if (p1 == -1)
  89     {
  90       puts ("1st vfork failed");
  91       result = 1;
  92     }
  93
  94   memset (&it, 0, sizeof (it));
  95   setitimer (ITIMER_REAL, &it, NULL);
  96
  97   pid_t p2 = 0;
  98   if (TEMP_FAILURE_RETRY (read (fd[0], &p2, sizeof (pid_t))) != sizeof (pid_t))
  99     {
 100       puts ("1st read failed");
 101       result = 1;
 102     }
 103   int r;
 104   if (TEMP_FAILURE_RETRY (waitpid (p1, &r, 0)) != p1)
 105     {
 106       puts ("1st waitpid failed");
 107       result = 1;
 108     }
 109   else if (r != 0)
 110     {
 111       puts ("write in 1st child failed");
 112       result = 1;
 113     }
 114
 115   /* Main process' ID.  */
 116   pid_t p0 = getpid ();
 117
 118   /* vfork() again, but after a getpid() in the main process.  */
 119   pid_t p3;
 120   if ((p3 = vfork ()) == 0)
 121     {
 122       pid_t p = getpid ();
 123       _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
 124     }
 125   else if (p1 == -1)
 126     {
 127       puts ("2nd vfork failed");
 128       result = 1;
 129     }
 130
 131   pid_t p4;
 132   if (TEMP_FAILURE_RETRY (read (fd[0], &p4, sizeof (pid_t))) != sizeof (pid_t))
 133     {
 134       puts ("2nd read failed");
 135       result = 1;
 136     }
 137   if (TEMP_FAILURE_RETRY (waitpid (p3, &r, 0)) != p3)
 138     {
 139       puts ("2nd waitpid failed");
 140       result = 1;
 141     }
 142   else if (r != 0)
 143     {
 144       puts ("write in 2nd child failed");
 145       result = 1;
 146     }
 147
 148   /* And getpid in the main process again.  */
 149   pid_t p5 = getpid ();
 150
 151   /* Analysis of the results.  */
 152   if (p0 != p5)
 153     {
 154       printf ("p0(%ld) != p5(%ld)\n", (long int) p0, (long int) p5);
 155       result = 1;
 156     }
 157
 158   if (p0 == p1)
 159     {
 160       printf ("p0(%ld) == p1(%ld)\n", (long int) p0, (long int) p1);
 161       result = 1;
 162     }
 163
 164   if (p1 != p2)
 165     {
 166       printf ("p1(%ld) != p2(%ld)\n", (long int) p1, (long int) p2);
 167       result = 1;
 168     }
 169
 170   if (p0 == p3)
 171     {
 172       printf ("p0(%ld) == p3(%ld)\n", (long int) p0, (long int) p3);
 173       result = 1;
 174     }
 175
 176   if (p3 != p4)
 177     {
 178       printf ("p3(%ld) != p4(%ld)\n", (long int) p3, (long int) p4);
 179       result = 1;
 180     }
 181
 182   close (fd[0]);
 183   close (fd[1]);
 184
 185   if (raise_fail)
 186     {
 187       puts ("raise failed");
 188       result = 1;
 189     }
 190
 191   if (result == 0)
 192     puts ("All OK");
 193
 194   return result;
 195 }
 196
 197 #define TEST_FUNCTION do_test ()
 198 #include "../test-skeleton.c"