nptl/tst-rwlock12.c

   1 /* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <pthread.h>
  22 #include <stdint.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <sys/mman.h>
  28 #include <sys/wait.h>
  29
  30
  31 static int
  32 do_test (void)
  33 {
  34   size_t ps = sysconf (_SC_PAGESIZE);
  35   char tmpfname[] = "/tmp/tst-rwlock12.XXXXXX";
  36   char data[ps];
  37   void *mem;
  38   int fd;
  39   pthread_mutex_t *m;
  40   pthread_mutexattr_t ma;
  41   pthread_rwlock_t *r;
  42   pthread_rwlockattr_t ra;
  43   pid_t pid;
  44   int status = 0;
  45
  46   fd = mkstemp (tmpfname);
  47   if (fd == -1)
  48     {
  49       printf ("cannot open temporary file: %m\n");
  50       return 1;
  51     }
  52
  53   /* Make sure it is always removed.  */
  54   unlink (tmpfname);
  55
  56   /* Create one page of data.  */
  57   memset (data, '\0', ps);
  58
  59   /* Write the data to the file.  */
  60   if (write (fd, data, ps) != (ssize_t) ps)
  61     {
  62       puts ("short write");
  63       return 1;
  64     }
  65
  66   mem = mmap (NULL, ps, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  67   if (mem == MAP_FAILED)
  68     {
  69       printf ("mmap failed: %m\n");
  70       return 1;
  71     }
  72
  73   r = (pthread_rwlock_t *) (((uintptr_t) mem + __alignof (pthread_rwlock_t))
  74                             & ~(__alignof (pthread_rwlock_t) - 1));
  75   /* The following assumes alignment for a mutex is at least as high
  76      as that for a rwlock.  Which is true in our case.  */
  77   m = (pthread_mutex_t *) (r + 1);
  78
  79   if (pthread_rwlockattr_init (&ra) != 0)
  80     {
  81       puts ("rwlockattr_init failed");
  82       return 1;
  83     }
  84
  85   if (pthread_rwlockattr_setpshared (&ra, PTHREAD_PROCESS_SHARED) != 0)
  86     {
  87       puts ("rwlockattr_setpshared failed");
  88       return 1;
  89     }
  90
  91   if (pthread_rwlock_init (r, &ra) != 0)
  92     {
  93       puts ("rwlock_init failed");
  94       return 1;
  95     }
  96
  97   if (pthread_mutexattr_init (&ma) != 0)
  98     {
  99       puts ("rwlockattr_init failed");
 100       return 1;
 101     }
 102
 103   if (pthread_mutexattr_setpshared (&ma, PTHREAD_PROCESS_SHARED) != 0)
 104     {
 105       puts ("mutexattr_setpshared failed");
 106       return 1;
 107     }
 108
 109   if (pthread_mutex_init (m, &ma) != 0)
 110     {
 111       puts ("mutex_init failed");
 112       return 1;
 113     }
 114
 115   /* Lock the mutex.  */
 116   if (pthread_mutex_lock (m) != 0)
 117     {
 118       puts ("mutex_lock failed");
 119       return 1;
 120     }
 121
 122   puts ("going to fork now");
 123   pid = fork ();
 124   if (pid == -1)
 125     {
 126       puts ("fork failed");
 127       return 1;
 128     }
 129   else if (pid == 0)
 130     {
 131       /* Lock the mutex.  */
 132       if (pthread_mutex_lock (m) != 0)
 133         {
 134           puts ("child: mutex_lock failed");
 135           return 1;
 136         }
 137
 138       /* Try to get the rwlock.  */
 139       if (pthread_rwlock_trywrlock (r) == 0)
 140         {
 141           puts ("rwlock_trywrlock succeeded");
 142           return 1;
 143         }
 144
 145       /* Try again.  */
 146       struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000000 };
 147       int e = pthread_rwlock_timedwrlock (r, &ts);
 148       if (e == 0)
 149         {
 150           puts ("rwlock_timedwrlock succeeded");
 151           return 1;
 152         }
 153       if (e != ETIMEDOUT)
 154         {
 155           puts ("rwlock_timedwrlock didn't return ETIMEDOUT");
 156           status = 1;
 157         }
 158
 159       if (pthread_rwlock_tryrdlock (r) == 0)
 160         {
 161           puts ("rwlock_tryrdlock succeeded");
 162           return 1;
 163         }
 164
 165       e = pthread_rwlock_timedrdlock (r, &ts);
 166       if (e == 0)
 167         {
 168           puts ("rwlock_timedrdlock succeeded");
 169           return 1;
 170         }
 171       if (e != ETIMEDOUT)
 172         {
 173           puts ("rwlock_timedrdlock didn't return ETIMEDOUT");
 174           status = 1;
 175         }
 176     }
 177   else
 178     {
 179       /* Lock the rwlock for writing.  */
 180       if (pthread_rwlock_wrlock (r) != 0)
 181         {
 182           puts ("rwlock_wrlock failed");
 183           kill (pid, SIGTERM);
 184           return 1;
 185         }
 186
 187       /* Allow the child to run.  */
 188       if (pthread_mutex_unlock (m) != 0)
 189         {
 190           puts ("mutex_unlock failed");
 191           kill (pid, SIGTERM);
 192           return 1;
 193         }
 194
 195       /* Just wait for the child.  */
 196       if (TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)) != pid)
 197         {
 198           puts ("waitpid failed");
 199           kill (pid, SIGTERM);
 200           return 1;
 201         }
 202     }
 203
 204   return status;
 205 }
 206
 207 #define TEST_FUNCTION do_test ()
 208 #include "../test-skeleton.c"