1  /* Test for vfork functions.
       2     Copyright (C) 2004-2023 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 <stdio.h>
      21  #include <stdlib.h>
      22  #include <unistd.h>
      23  #include <sys/types.h>
      24  #include <sys/wait.h>
      25  
      26  /* This test relies on non-POSIX functionality since the child
      27     processes call write and getpid.  */
      28  static int
      29  do_test (void)
      30  {
      31    int result = 0;
      32    int fd[2];
      33  
      34    if (pipe (fd) == -1)
      35      {
      36        puts ("pipe failed");
      37        return 1;
      38      }
      39  
      40    /* First vfork() without previous getpid().  */
      41    pid_t p1;
      42    if ((p1 = vfork ()) == 0)
      43      {
      44        pid_t p = getpid ();
      45        _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
      46      }
      47    else if (p1 == -1)
      48      {
      49        puts ("1st vfork failed");
      50        result = 1;
      51      }
      52  
      53    pid_t p2 = 0;
      54    if (TEMP_FAILURE_RETRY (read (fd[0], &p2, sizeof (pid_t))) != sizeof (pid_t))
      55      {
      56        puts ("1st read failed");
      57        result = 1;
      58      }
      59    int r;
      60    if (TEMP_FAILURE_RETRY (waitpid (p1, &r, 0)) != p1)
      61      {
      62        puts ("1st waitpid failed");
      63        result = 1;
      64      }
      65    else if (r != 0)
      66      {
      67        puts ("write in 1st child failed");
      68        result = 1;
      69      }
      70  
      71    /* Main process' ID.  */
      72    pid_t p0 = getpid ();
      73  
      74    /* vfork() again, but after a getpid() in the main process.  */
      75    pid_t p3;
      76    if ((p3 = vfork ()) == 0)
      77      {
      78        pid_t p = getpid ();
      79        _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
      80      }
      81    else if (p1 == -1)
      82      {
      83        puts ("2nd vfork failed");
      84        result = 1;
      85      }
      86  
      87    pid_t p4;
      88    if (TEMP_FAILURE_RETRY (read (fd[0], &p4, sizeof (pid_t))) != sizeof (pid_t))
      89      {
      90        puts ("2nd read failed");
      91        result = 1;
      92      }
      93    if (TEMP_FAILURE_RETRY (waitpid (p3, &r, 0)) != p3)
      94      {
      95        puts ("2nd waitpid failed");
      96        result = 1;
      97      }
      98    else if (r != 0)
      99      {
     100        puts ("write in 2nd child failed");
     101        result = 1;
     102      }
     103  
     104    /* And getpid in the main process again.  */
     105    pid_t p5 = getpid ();
     106  
     107    /* Analysis of the results.  */
     108    if (p0 != p5)
     109      {
     110        printf ("p0(%ld) != p5(%ld)\n", (long int) p0, (long int) p5);
     111        result = 1;
     112      }
     113  
     114    if (p0 == p1)
     115      {
     116        printf ("p0(%ld) == p1(%ld)\n", (long int) p0, (long int) p1);
     117        result = 1;
     118      }
     119  
     120    if (p1 != p2)
     121      {
     122        printf ("p1(%ld) != p2(%ld)\n", (long int) p1, (long int) p2);
     123        result = 1;
     124      }
     125  
     126    if (p0 == p3)
     127      {
     128        printf ("p0(%ld) == p3(%ld)\n", (long int) p0, (long int) p3);
     129        result = 1;
     130      }
     131  
     132    if (p3 != p4)
     133      {
     134        printf ("p3(%ld) != p4(%ld)\n", (long int) p3, (long int) p4);
     135        result = 1;
     136      }
     137  
     138    close (fd[0]);
     139    close (fd[1]);
     140  
     141    if (result == 0)
     142      puts ("All OK");
     143  
     144    return result;
     145  }
     146  
     147  #define TEST_FUNCTION do_test ()
     148  #include "../test-skeleton.c"