rt/tst-shm.c

   1 /* Test program for POSIX shm_* functions.
   2    Copyright (C) 2000-2013 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
   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    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <error.h>
  22 #include <fcntl.h>
  23 #include <signal.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <time.h>
  28 #include <unistd.h>
  29 #include <sys/mman.h>
  30 #include <sys/stat.h>
  31 #include <sys/wait.h>
  32
  33
  34 /* We want to see output immediately.  */
  35 #define STDOUT_UNBUFFERED
  36
  37
  38 static int
  39 do_open (void)
  40 {
  41   int fd;
  42
  43   /* Create the shared memory object.  */
  44   fd = shm_open ("/shm-test", O_RDWR, 0600);
  45   if (fd == -1)
  46     {
  47       /* We don't regard this as a bug.  Simply don't run the test.  It could
  48          means there is no such implementation or the object is already in
  49          use in which case we don't want to disturb.  */
  50       perror ("failed to open shared memory object: shm_open");
  51       return -1;
  52     }
  53
  54   return fd;
  55 }
  56
  57
  58 static void
  59 worker (int write_now)
  60 {
  61   struct timespec ts;
  62   struct stat64 st;
  63   int i;
  64   int fd = do_open ();
  65   char *mem;
  66
  67   if (fd == -1)
  68     exit (fd);
  69
  70   if (fstat64 (fd, &st) == -1)
  71     error (EXIT_FAILURE, 0, "stat failed");
  72   if (st.st_size != 4000)
  73     error (EXIT_FAILURE, 0, "size incorrect");
  74
  75   mem = mmap (NULL, 4000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  76   if (mem == MAP_FAILED)
  77     error (EXIT_FAILURE, 0, "mmap failed");
  78
  79   ts.tv_sec = 0;
  80   ts.tv_nsec = 500000000;
  81
  82   if (write_now)
  83     for (i = 0; i <= 4; ++i)
  84       mem[i] = i;
  85   else
  86     /* Wait until the first bytes of the memory region are 0, 1, 2, 3, 4.  */
  87     while (1)
  88       {
  89         for (i = 0; i <= 4; ++i)
  90           if (mem[i] != i)
  91             break;
  92
  93         if (i > 4)
  94           /* OK, that's done.  */
  95           break;
  96
  97         nanosleep (&ts, NULL);
  98       }
  99
 100   if (!write_now)
 101     for (i = 0; i <= 4; ++i)
 102       mem[i] = 4 + i;
 103   else
 104     /* Wait until the first bytes of the memory region are 4, 5, 6, 7, 8.  */
 105     while (1)
 106       {
 107         for (i = 0; i <= 4; ++i)
 108           if (mem[i] != 4 + i)
 109             break;
 110
 111         if (i > 4)
 112           /* OK, that's done.  */
 113           break;
 114
 115         nanosleep (&ts, NULL);
 116       }
 117
 118   if (munmap (mem, 4000) == -1)
 119     error (EXIT_FAILURE, errno, "munmap");
 120
 121   close (fd);
 122
 123   exit (0);
 124 }
 125
 126
 127 static int
 128 do_test (void)
 129 {
 130   int fd;
 131   pid_t pid1;
 132   pid_t pid2;
 133   int status1;
 134   int status2;
 135   struct stat64 st;
 136
 137   /* Create the shared memory object.  */
 138   fd = shm_open ("/shm-test", O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600);
 139   if (fd == -1)
 140     {
 141       /* We don't regard this as a bug.  Simply don't run the test.  It could
 142          means there is no such implementation or the object is already in
 143          use in which case we don't want to disturb.  */
 144       perror ("failed to create a shared memory object: shm_open");
 145       return 0;
 146     }
 147
 148   /* Size the object.  We make it 4000 bytes long.  */
 149   if (ftruncate (fd, 4000) == -1)
 150     {
 151       /* This failed.  Must be a bug in the implementation of the
 152          shared memory itself.  */
 153       perror ("failed to size of shared memory object: ftruncate");
 154       close (fd);
 155       shm_unlink ("/shm-test");
 156       return 0;
 157     }
 158
 159   if (fstat64 (fd, &st) == -1)
 160     {
 161       shm_unlink ("/shm-test");
 162       error (EXIT_FAILURE, 0, "initial stat failed");
 163     }
 164   if (st.st_size != 4000)
 165     {
 166       shm_unlink ("/shm-test");
 167       error (EXIT_FAILURE, 0, "initial size not correct");
 168     }
 169
 170   /* Spawn to processes which will do the work.  */
 171   pid1 = fork ();
 172   if (pid1 == 0)
 173     worker (0);
 174   else if (pid1 == -1)
 175     {
 176       /* Couldn't create a second process.  */
 177       perror ("fork");
 178       close (fd);
 179       shm_unlink ("/shm-test");
 180       return 0;
 181     }
 182
 183   pid2 = fork ();
 184   if (pid2 == 0)
 185     worker (1);
 186   else if (pid2 == -1)
 187     {
 188       /* Couldn't create a second process.  */
 189       int ignore;
 190       perror ("fork");
 191       kill (pid1, SIGTERM);
 192       waitpid (pid1, &ignore, 0);
 193       close (fd);
 194       shm_unlink ("/shm-test");
 195       return 0;
 196     }
 197
 198   /* Wait until the two processes are finished.  */
 199   waitpid (pid1, &status1, 0);
 200   waitpid (pid2, &status2, 0);
 201
 202   /* Now we can unlink the shared object.  */
 203   shm_unlink ("/shm-test");
 204
 205   return (!WIFEXITED (status1) || WEXITSTATUS (status1) != 0
 206           || !WIFEXITED (status2) || WEXITSTATUS (status2) != 0);
 207 }
 208 #define TEST_FUNCTION do_test ()
 209
 210 #define CLEANUP_HANDLER shm_unlink ("/shm-test");
 211
 212
 213 #include "../test-skeleton.c"