rt/tst-shm.c

   1 /* Test program for POSIX shm_* functions.
   2    Copyright (C) 2000, 2002 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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <error.h>
  23 #include <fcntl.h>
  24 #include <signal.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <time.h>
  29 #include <unistd.h>
  30 #include <sys/mman.h>
  31 #include <sys/stat.h>
  32 #include <sys/wait.h>
  33
  34
  35 /* We want to see output immediately.  */
  36 #define STDOUT_UNBUFFERED
  37
  38
  39 static int
  40 do_open (void)
  41 {
  42   int fd;
  43
  44   /* Create the shared memory object.  */
  45   fd = shm_open ("/shm-test", O_RDWR, 0600);
  46   if (fd == -1)
  47     {
  48       /* We don't regard this as a bug.  Simply don't run the test.  It could
  49          means there is no such implementation or the object is already in
  50          use in which case we don't want to disturb.  */
  51       perror ("failed to open shared memory object: shm_open");
  52       return -1;
  53     }
  54
  55   return fd;
  56 }
  57
  58
  59 static void
  60 worker (int write_now)
  61 {
  62   struct timespec ts;
  63   struct stat64 st;
  64   int i;
  65   int fd = do_open ();
  66   char *mem;
  67
  68   if (fd == -1)
  69     exit (fd);
  70
  71   if (fstat64 (fd, &st) == -1)
  72     error (EXIT_FAILURE, 0, "stat failed");
  73   if (st.st_size != 4000)
  74     error (EXIT_FAILURE, 0, "size incorrect");
  75
  76   mem = mmap (NULL, 4000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  77   if (mem == NULL)
  78     error (EXIT_FAILURE, 0, "mmap failed");
  79
  80   ts.tv_sec = 0;
  81   ts.tv_nsec = 500000000;
  82
  83   if (write_now)
  84     for (i = 0; i <= 4; ++i)
  85       mem[i] = i;
  86   else
  87     /* Wait until the first bytes of the memory region are 0, 1, 2, 3, 4.  */
  88     while (1)
  89       {
  90         for (i = 0; i <= 4; ++i)
  91           if (mem[i] != i)
  92             break;
  93
  94         if (i > 4)
  95           /* OK, that's done.  */
  96           break;
  97
  98         nanosleep (&ts, NULL);
  99       }
 100
 101   if (!write_now)
 102     for (i = 0; i <= 4; ++i)
 103       mem[i] = 4 + i;
 104   else
 105     /* Wait until the first bytes of the memory region are 4, 5, 6, 7, 8.  */
 106     while (1)
 107       {
 108         for (i = 0; i <= 4; ++i)
 109           if (mem[i] != 4 + i)
 110             break;
 111
 112         if (i > 4)
 113           /* OK, that's done.  */
 114           break;
 115
 116         nanosleep (&ts, NULL);
 117       }
 118
 119   if (munmap (mem, 4000) == -1)
 120     error (EXIT_FAILURE, errno, "munmap");
 121
 122   close (fd);
 123
 124   exit (0);
 125 }
 126
 127
 128 static int
 129 do_test (void)
 130 {
 131   int fd;
 132   pid_t pid1;
 133   pid_t pid2;
 134   int status1;
 135   int status2;
 136   struct stat64 st;
 137
 138   /* Create the shared memory object.  */
 139   fd = shm_open ("/shm-test", O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600);
 140   if (fd == -1)
 141     {
 142       /* We don't regard this as a bug.  Simply don't run the test.  It could
 143          means there is no such implementation or the object is already in
 144          use in which case we don't want to disturb.  */
 145       perror ("failed to create a shared memory object: shm_open");
 146       return 0;
 147     }
 148
 149   /* Size the object.  We make it 4000 bytes long.  */
 150   if (ftruncate (fd, 4000) == -1)
 151     {
 152       /* This failed.  Must be a bug in the implementation of the
 153          shared memory itself.  */
 154       perror ("failed to size of shared memory object: ftruncate");
 155       close (fd);
 156       shm_unlink ("/shm-test");
 157       return 0;
 158     }
 159
 160   if (fstat64 (fd, &st) == -1)
 161     {
 162       shm_unlink ("/shm-test");
 163       error (EXIT_FAILURE, 0, "initial stat failed");
 164     }
 165   if (st.st_size != 4000)
 166     {
 167       shm_unlink ("/shm-test");
 168       error (EXIT_FAILURE, 0, "initial size not correct");
 169     }
 170
 171   /* Spawn to processes which will do the work.  */
 172   pid1 = fork ();
 173   if (pid1 == 0)
 174     worker (0);
 175   else if (pid1 == -1)
 176     {
 177       /* Couldn't create a second process.  */
 178       perror ("fork");
 179       close (fd);
 180       shm_unlink ("/shm-test");
 181       return 0;
 182     }
 183
 184   pid2 = fork ();
 185   if (pid2 == 0)
 186     worker (1);
 187   else if (pid2 == -1)
 188     {
 189       /* Couldn't create a second process.  */
 190       int ignore;
 191       perror ("fork");
 192       kill (pid1, SIGTERM);
 193       waitpid (pid1, &ignore, 0);
 194       close (fd);
 195       shm_unlink ("/shm-test");
 196       return 0;
 197     }
 198
 199   /* Wait until the two processes are finished.  */
 200   waitpid (pid1, &status1, 0);
 201   waitpid (pid2, &status2, 0);
 202
 203   /* Now we can unlink the shared object.  */
 204   shm_unlink ("/shm-test");
 205
 206   return (!WIFEXITED (status1) || WEXITSTATUS (status1) != 0
 207           || !WIFEXITED (status2) || WEXITSTATUS (status2) != 0);
 208 }
 209 #define TEST_FUNCTION do_test ()
 210
 211 #define CLEANUP_HANDLER shm_unlink ("/shm-test");
 212
 213
 214 #include "../test-skeleton.c"