nptl/tst-rwlock12.c

   1 /* Copyright (C) 2002-2017 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <pthread.h>
  21 #include <stdint.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26 #include <sys/mman.h>
  27 #include <sys/wait.h>
  28
  29
  30 static int
  31 do_test (void)
  32 {
  33   size_t ps = sysconf (_SC_PAGESIZE);
  34   char tmpfname[] = "/tmp/tst-rwlock12.XXXXXX";
  35   char data[ps];
  36   void *mem;
  37   int fd;
  38   pthread_mutex_t *m;
  39   pthread_mutexattr_t ma;
  40   pthread_rwlock_t *r;
  41   pthread_rwlockattr_t ra;
  42   pid_t pid;
  43   int status = 0;
  44
  45   fd = mkstemp (tmpfname);
  46   if (fd == -1)
  47     {
  48       printf ("cannot open temporary file: %m\n");
  49       return 1;
  50     }
  51
  52   /* Make sure it is always removed.  */
  53   unlink (tmpfname);
  54
  55   /* Create one page of data.  */
  56   memset (data, '\0', ps);
  57
  58   /* Write the data to the file.  */
  59   if (write (fd, data, ps) != (ssize_t) ps)
  60     {
  61       puts ("short write");
  62       return 1;
  63     }
  64
  65   mem = mmap (NULL, ps, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
  66   if (mem == MAP_FAILED)
  67     {
  68       printf ("mmap failed: %m\n");
  69       return 1;
  70     }
  71
  72   r = (pthread_rwlock_t *) (((uintptr_t) mem + __alignof (pthread_rwlock_t))
  73                             & ~(__alignof (pthread_rwlock_t) - 1));
  74   /* The following assumes alignment for a mutex is at least as high
  75      as that for a rwlock.  Which is true in our case.  */
  76   m = (pthread_mutex_t *) (r + 1);
  77
  78   if (pthread_rwlockattr_init (&ra) != 0)
  79     {
  80       puts ("rwlockattr_init failed");
  81       return 1;
  82     }
  83
  84   if (pthread_rwlockattr_setpshared (&ra, PTHREAD_PROCESS_SHARED) != 0)
  85     {
  86       puts ("rwlockattr_setpshared failed");
  87       return 1;
  88     }
  89
  90   if (pthread_rwlock_init (r, &ra) != 0)
  91     {
  92       puts ("rwlock_init failed");
  93       return 1;
  94     }
  95
  96   if (pthread_mutexattr_init (&ma) != 0)
  97     {
  98       puts ("rwlockattr_init failed");
  99       return 1;
 100     }
 101
 102   if (pthread_mutexattr_setpshared (&ma, PTHREAD_PROCESS_SHARED) != 0)
 103     {
 104       puts ("mutexattr_setpshared failed");
 105       return 1;
 106     }
 107
 108   if (pthread_mutex_init (m, &ma) != 0)
 109     {
 110       puts ("mutex_init failed");
 111       return 1;
 112     }
 113
 114   /* Lock the mutex.  */
 115   if (pthread_mutex_lock (m) != 0)
 116     {
 117       puts ("mutex_lock failed");
 118       return 1;
 119     }
 120
 121   puts ("going to fork now");
 122   pid = fork ();
 123   if (pid == -1)
 124     {
 125       puts ("fork failed");
 126       return 1;
 127     }
 128   else if (pid == 0)
 129     {
 130       /* Lock the mutex.  */
 131       if (pthread_mutex_lock (m) != 0)
 132         {
 133           puts ("child: mutex_lock failed");
 134           return 1;
 135         }
 136
 137       /* Try to get the rwlock.  */
 138       if (pthread_rwlock_trywrlock (r) == 0)
 139         {
 140           puts ("rwlock_trywrlock succeeded");
 141           return 1;
 142         }
 143
 144       /* Try again.  */
 145       struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000000 };
 146       int e = pthread_rwlock_timedwrlock (r, &ts);
 147       if (e == 0)
 148         {
 149           puts ("rwlock_timedwrlock succeeded");
 150           return 1;
 151         }
 152       if (e != ETIMEDOUT)
 153         {
 154           puts ("rwlock_timedwrlock didn't return ETIMEDOUT");
 155           status = 1;
 156         }
 157
 158       if (pthread_rwlock_tryrdlock (r) == 0)
 159         {
 160           puts ("rwlock_tryrdlock succeeded");
 161           return 1;
 162         }
 163
 164       e = pthread_rwlock_timedrdlock (r, &ts);
 165       if (e == 0)
 166         {
 167           puts ("rwlock_timedrdlock succeeded");
 168           return 1;
 169         }
 170       if (e != ETIMEDOUT)
 171         {
 172           puts ("rwlock_timedrdlock didn't return ETIMEDOUT");
 173           status = 1;
 174         }
 175     }
 176   else
 177     {
 178       /* Lock the rwlock for writing.  */
 179       if (pthread_rwlock_wrlock (r) != 0)
 180         {
 181           puts ("rwlock_wrlock failed");
 182           kill (pid, SIGTERM);
 183           return 1;
 184         }
 185
 186       /* Allow the child to run.  */
 187       if (pthread_mutex_unlock (m) != 0)
 188         {
 189           puts ("mutex_unlock failed");
 190           kill (pid, SIGTERM);
 191           return 1;
 192         }
 193
 194       /* Just wait for the child.  */
 195       if (TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)) != pid)
 196         {
 197           puts ("waitpid failed");
 198           kill (pid, SIGTERM);
 199           return 1;
 200         }
 201     }
 202
 203   return status;
 204 }
 205
 206 #define TEST_FUNCTION do_test ()
 207 #include "../test-skeleton.c"