rt/tst-shm.c

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