posix/tst-_Fork.c

   1 /* Basic tests for _Fork.
   2    Copyright (C) 2021-2023 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 <array_length.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <pthread.h>
  23 #include <stdbool.h>
  24 #include <support/check.h>
  25 #include <support/xsignal.h>
  26 #include <support/temp_file.h>
  27 #include <support/xunistd.h>
  28 #include <support/xthread.h>
  29
  30 /* For single-thread, _Fork behaves like fork.  */
  31 static int
  32 singlethread_test (void)
  33 {
  34   const char testdata1[] = "abcdefghijklmnopqrtuvwxz";
  35   enum { testdatalen1 = array_length (testdata1) };
  36   const char testdata2[] = "01234567890";
  37   enum { testdatalen2 = array_length (testdata2) };
  38
  39   pid_t ppid = getpid ();
  40
  41   int tempfd = create_temp_file ("tst-_Fork", NULL);
  42
  43   /* Check if the opened file is shared between process by read and write
  44      some data on parent and child processes.  */
  45   xwrite (tempfd, testdata1, testdatalen1);
  46   off_t off = xlseek (tempfd, 0, SEEK_CUR);
  47   TEST_COMPARE (off, testdatalen1);
  48
  49   pid_t pid = _Fork ();
  50   TEST_VERIFY_EXIT (pid != -1);
  51   if (pid == 0)
  52     {
  53       TEST_VERIFY_EXIT (getpid () != ppid);
  54       TEST_COMPARE (getppid(), ppid);
  55
  56       TEST_COMPARE (xlseek (tempfd, 0, SEEK_CUR), testdatalen1);
  57
  58       xlseek (tempfd, 0, SEEK_SET);
  59       char buf[testdatalen1];
  60       TEST_COMPARE (read (tempfd, buf, sizeof (buf)), testdatalen1);
  61       TEST_COMPARE_BLOB (buf, testdatalen1, testdata1, testdatalen1);
  62
  63       xlseek (tempfd, 0, SEEK_SET);
  64       xwrite (tempfd, testdata2, testdatalen2);
  65
  66       xclose (tempfd);
  67
  68       _exit (EXIT_SUCCESS);
  69     }
  70
  71   int status;
  72   xwaitpid (pid, &status, 0);
  73   TEST_VERIFY (WIFEXITED (status));
  74   TEST_COMPARE (WEXITSTATUS (status), EXIT_SUCCESS);
  75
  76   TEST_COMPARE (xlseek (tempfd, 0, SEEK_CUR), testdatalen2);
  77
  78   xlseek (tempfd, 0, SEEK_SET);
  79   char buf[testdatalen2];
  80   TEST_COMPARE (read (tempfd, buf, sizeof (buf)), testdatalen2);
  81
  82   TEST_COMPARE_BLOB (buf, testdatalen2, testdata2, testdatalen2);
  83
  84   return 0;
  85 }
  86
  87
  88 #define SIG_PID_EXIT_CODE 20
  89
  90 static bool atfork_prepare_var;
  91 static bool atfork_parent_var;
  92 static bool atfork_child_var;
  93
  94 static void
  95 atfork_prepare (void)
  96 {
  97   atfork_prepare_var = true;
  98 }
  99
 100 static void
 101 atfork_parent (void)
 102 {
 103   atfork_parent_var = true;
 104 }
 105
 106 static void
 107 atfork_child (void)
 108 {
 109   atfork_child_var = true;
 110 }
 111
 112 /* Different than fork, _Fork does not execute any pthread_atfork
 113    handlers.  */
 114 static int
 115 singlethread_atfork_test (void)
 116 {
 117   pthread_atfork (atfork_prepare, atfork_parent, atfork_child);
 118   singlethread_test ();
 119   TEST_VERIFY (!atfork_prepare_var);
 120   TEST_VERIFY (!atfork_parent_var);
 121   TEST_VERIFY (!atfork_child_var);
 122
 123   return 0;
 124 }
 125
 126 static void *
 127 mt_atfork_test (void *args)
 128 {
 129   singlethread_atfork_test ();
 130
 131   return NULL;
 132 }
 133
 134 static int
 135 multithread_atfork_test (void)
 136 {
 137   pthread_t thr = xpthread_create (NULL, mt_atfork_test, NULL);
 138   xpthread_join (thr);
 139
 140   return 0;
 141 }
 142
 143
 144 static int
 145 do_test (void)
 146 {
 147   singlethread_atfork_test ();
 148   multithread_atfork_test ();
 149
 150   return 0;
 151 }
 152
 153 #include <support/test-driver.c>