posix/tst-vfork2.c

   1 /* Test for vfork functions.
   2    Copyright (C) 2004-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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 <signal.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <time.h>
  25 #include <unistd.h>
  26 #include <sys/time.h>
  27 #include <sys/types.h>
  28 #include <sys/wait.h>
  29
  30 int raise_fail;
  31
  32 static void
  33 alrm (int sig)
  34 {
  35   if (raise (SIGUSR1) < 0)
  36     raise_fail = 1;
  37 }
  38
  39 /* This test relies on non-POSIX functionality since the child
  40    processes call write, nanosleep and getpid.  */
  41 static int
  42 do_test (void)
  43 {
  44   int result = 0;
  45   int fd[2];
  46
  47   signal (SIGUSR1, SIG_IGN);
  48
  49   struct sigaction sa;
  50   sa.sa_handler = alrm;
  51   sigemptyset (&sa.sa_mask);
  52   sa.sa_flags = 0;
  53   if (sigaction (SIGALRM, &sa, NULL) < 0)
  54     {
  55       puts ("couldn't set up SIGALRM handler");
  56       return 1;
  57     }
  58
  59   if (pipe (fd) == -1)
  60     {
  61       puts ("pipe failed");
  62       return 1;
  63     }
  64
  65   struct itimerval it;
  66   it.it_value.tv_sec = 0;
  67   it.it_value.tv_usec = 200 * 1000;
  68   it.it_interval = it.it_value;
  69   if (setitimer (ITIMER_REAL, &it, NULL) < 0)
  70     {
  71       puts ("couldn't set up timer");
  72       return 1;
  73     }
  74
  75   /* First vfork() without previous getpid().  */
  76   pid_t p1;
  77   if ((p1 = vfork ()) == 0)
  78     {
  79       pid_t p = getpid ();
  80
  81       struct timespec ts;
  82       ts.tv_sec = 1;
  83       ts.tv_nsec = 0;
  84       TEMP_FAILURE_RETRY (nanosleep (&ts, &ts));
  85       _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
  86     }
  87   else if (p1 == -1)
  88     {
  89       puts ("1st vfork failed");
  90       result = 1;
  91     }
  92
  93   memset (&it, 0, sizeof (it));
  94   setitimer (ITIMER_REAL, &it, NULL);
  95
  96   pid_t p2 = 0;
  97   if (TEMP_FAILURE_RETRY (read (fd[0], &p2, sizeof (pid_t))) != sizeof (pid_t))
  98     {
  99       puts ("1st read failed");
 100       result = 1;
 101     }
 102   int r;
 103   if (TEMP_FAILURE_RETRY (waitpid (p1, &r, 0)) != p1)
 104     {
 105       puts ("1st waitpid failed");
 106       result = 1;
 107     }
 108   else if (r != 0)
 109     {
 110       puts ("write in 1st child failed");
 111       result = 1;
 112     }
 113
 114   /* Main process' ID.  */
 115   pid_t p0 = getpid ();
 116
 117   /* vfork() again, but after a getpid() in the main process.  */
 118   pid_t p3;
 119   if ((p3 = vfork ()) == 0)
 120     {
 121       pid_t p = getpid ();
 122       _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
 123     }
 124   else if (p1 == -1)
 125     {
 126       puts ("2nd vfork failed");
 127       result = 1;
 128     }
 129
 130   pid_t p4;
 131   if (TEMP_FAILURE_RETRY (read (fd[0], &p4, sizeof (pid_t))) != sizeof (pid_t))
 132     {
 133       puts ("2nd read failed");
 134       result = 1;
 135     }
 136   if (TEMP_FAILURE_RETRY (waitpid (p3, &r, 0)) != p3)
 137     {
 138       puts ("2nd waitpid failed");
 139       result = 1;
 140     }
 141   else if (r != 0)
 142     {
 143       puts ("write in 2nd child failed");
 144       result = 1;
 145     }
 146
 147   /* And getpid in the main process again.  */
 148   pid_t p5 = getpid ();
 149
 150   /* Analysis of the results.  */
 151   if (p0 != p5)
 152     {
 153       printf ("p0(%ld) != p5(%ld)\n", (long int) p0, (long int) p5);
 154       result = 1;
 155     }
 156
 157   if (p0 == p1)
 158     {
 159       printf ("p0(%ld) == p1(%ld)\n", (long int) p0, (long int) p1);
 160       result = 1;
 161     }
 162
 163   if (p1 != p2)
 164     {
 165       printf ("p1(%ld) != p2(%ld)\n", (long int) p1, (long int) p2);
 166       result = 1;
 167     }
 168
 169   if (p0 == p3)
 170     {
 171       printf ("p0(%ld) == p3(%ld)\n", (long int) p0, (long int) p3);
 172       result = 1;
 173     }
 174
 175   if (p3 != p4)
 176     {
 177       printf ("p3(%ld) != p4(%ld)\n", (long int) p3, (long int) p4);
 178       result = 1;
 179     }
 180
 181   close (fd[0]);
 182   close (fd[1]);
 183
 184   if (raise_fail)
 185     {
 186       puts ("raise failed");
 187       result = 1;
 188     }
 189
 190   if (result == 0)
 191     puts ("All OK");
 192
 193   return result;
 194 }
 195
 196 #define TEST_FUNCTION do_test ()
 197 #include "../test-skeleton.c"