rt/tst-shm.c

   1 /* Test program for POSIX shm_* functions.
   2    Copyright (C) 2000 Free Software Foundation, Inc.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 2000.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  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 stat st;
  63   int i;
  64   int fd = do_open ();
  65   char *mem;
  66
  67   if (fd == -1)
  68     exit (fd);
  69
  70   if (fstat (fd, &st) == -1 || st.st_size != 4000)
  71     error (EXIT_FAILURE, 0, "stat failed");
  72
  73   mem = mmap (NULL, 4000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  74   if (mem == NULL)
  75     error (EXIT_FAILURE, 0, "mmap failed");
  76
  77   ts.tv_sec = 0;
  78   ts.tv_nsec = 500000000;
  79
  80   if (write_now)
  81     for (i = 0; i <= 4; ++i)
  82       mem[i] = i;
  83   else
  84     /* Wait until the first bytes of the memory region are 0, 1, 2, 3, 4.  */
  85     while (1)
  86       {
  87         for (i = 0; i <= 4; ++i)
  88           if (mem[i] != i)
  89             break;
  90
  91         if (i > 4)
  92           /* OK, that's done.  */
  93           break;
  94
  95         nanosleep (&ts, NULL);
  96       }
  97
  98   if (!write_now)
  99     for (i = 0; i <= 4; ++i)
 100       mem[i] = 4 + i;
 101   else
 102     /* Wait until the first bytes of the memory region are 4, 5, 6, 7, 8.  */
 103     while (1)
 104       {
 105         for (i = 0; i <= 4; ++i)
 106           if (mem[i] != 4 + i)
 107             break;
 108
 109         if (i > 4)
 110           /* OK, that's done.  */
 111           break;
 112
 113         nanosleep (&ts, NULL);
 114       }
 115
 116   if (munmap (mem, 4000) == -1)
 117     error (EXIT_FAILURE, errno, "munmap");
 118
 119   close (fd);
 120
 121   exit (0);
 122 }
 123
 124
 125 int
 126 do_test (void)
 127 {
 128   int fd;
 129   pid_t pid1;
 130   pid_t pid2;
 131   int status1;
 132   int status2;
 133
 134   /* Create the shared memory object.  */
 135   fd = shm_open ("/shm-test", O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600);
 136   if (fd == -1)
 137     {
 138       /* We don't regard this as a bug.  Simply don't run the test.  It could
 139          means there is no such implementation or the object is already in
 140          use in which case we don't want to disturb.  */
 141       perror ("failed to create a shared memory object: shm_open");
 142       return 0;
 143     }
 144
 145   /* Size the object.  We make it 4000 bytes long.  */
 146   if (ftruncate (fd, 4000) == -1)
 147     {
 148       /* This failed.  Must be a bug in the implementation of the
 149          shared memory itself.  */
 150       perror ("failed to size of shared memory object: ftruncate");
 151       close (fd);
 152       shm_unlink ("/shm-test");
 153       return 0;
 154     }
 155
 156   /* Spawn to processes which will do the work.  */
 157   pid1 = fork ();
 158   if (pid1 == 0)
 159     worker (0);
 160   else if (pid1 == -1)
 161     {
 162       /* Couldn't create a second process.  */
 163       perror ("fork");
 164       close (fd);
 165       shm_unlink ("/shm-test");
 166       return 0;
 167     }
 168
 169   pid2 = fork ();
 170   if (pid2 == 0)
 171     worker (1);
 172   else if (pid2 == -1)
 173     {
 174       /* Couldn't create a second process.  */
 175       int ignore;
 176       perror ("fork");
 177       kill (pid1, SIGTERM);
 178       waitpid (pid1, &ignore, 0);
 179       close (fd);
 180       shm_unlink ("/shm-test");
 181       return 0;
 182     }
 183
 184   /* Wait until the two processes are finished.  */
 185   waitpid (pid1, &status1, 0);
 186   waitpid (pid2, &status2, 0);
 187
 188   /* Now we can unlink the shared object.  */
 189   shm_unlink ("/shm-test");
 190
 191   return (!WIFEXITED (status1) || WEXITSTATUS (status1) != 0
 192           || !WIFEXITED (status2) || WEXITSTATUS (status2) != 0);
 193 }
 194 #define TEST_FUNCTION do_test ()
 195
 196 #define CLEANUP_HANDLER shm_unlink ("/shm-test");
 197
 198
 199 #include "../test-skeleton.c"