nptl/tst-rwlock4.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-rwlock4.XXXXXX";
  35   char data[ps];
  36   void *mem;
  37   int fd;
  38   pthread_rwlock_t *r;
  39   pthread_rwlockattr_t a;
  40   pid_t pid;
  41   char *p;
  42   int err;
  43   int s;
  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   p = (char *) (r + 1);
  75
  76   if (pthread_rwlockattr_init (&a) != 0)
  77     {
  78       puts ("rwlockattr_init failed");
  79       return 1;
  80     }
  81
  82   if (pthread_rwlockattr_getpshared (&a, &s) != 0)
  83     {
  84       puts ("1st rwlockattr_getpshared failed");
  85       return 1;
  86     }
  87
  88   if (s != PTHREAD_PROCESS_PRIVATE)
  89     {
  90       puts ("default pshared value wrong");
  91       return 1;
  92     }
  93
  94   if (pthread_rwlockattr_setpshared (&a, PTHREAD_PROCESS_SHARED) != 0)
  95     {
  96       puts ("rwlockattr_setpshared failed");
  97       return 1;
  98     }
  99
 100   if (pthread_rwlockattr_getpshared (&a, &s) != 0)
 101     {
 102       puts ("2nd rwlockattr_getpshared failed");
 103       return 1;
 104     }
 105
 106   if (s != PTHREAD_PROCESS_SHARED)
 107     {
 108       puts ("pshared value after setpshared call wrong");
 109       return 1;
 110     }
 111
 112   if (pthread_rwlock_init (r, &a) != 0)
 113     {
 114       puts ("rwlock_init failed");
 115       return 1;
 116     }
 117
 118   if (pthread_rwlock_rdlock (r) != 0)
 119     {
 120       puts ("rwlock_rdlock failed");
 121       return 1;
 122     }
 123
 124   if (pthread_rwlockattr_destroy (&a) != 0)
 125     {
 126       puts ("rwlockattr_destroy failed");
 127       return 1;
 128     }
 129
 130   err = pthread_rwlock_trywrlock (r);
 131   if (err == 0)
 132     {
 133       puts ("rwlock_trywrlock succeeded");
 134       return 1;
 135     }
 136   else if (err != EBUSY)
 137     {
 138       puts ("rwlock_trywrlock didn't return EBUSY");
 139       return 1;
 140     }
 141
 142   *p = 0;
 143
 144   puts ("going to fork now");
 145   pid = fork ();
 146   if (pid == -1)
 147     {
 148       puts ("fork failed");
 149       return 1;
 150     }
 151   else if (pid == 0)
 152     {
 153       /* Play some lock ping-pong.  It's our turn to unlock first.  */
 154       if ((*p)++ != 0)
 155         {
 156           puts ("child: *p != 0");
 157           return 1;
 158         }
 159
 160       if (pthread_rwlock_unlock (r) != 0)
 161         {
 162           puts ("child: 1st rwlock_unlock failed");
 163           return 1;
 164         }
 165
 166       puts ("child done");
 167     }
 168   else
 169     {
 170       if (pthread_rwlock_wrlock (r) != 0)
 171         {
 172           puts ("parent: rwlock_wrlock failed");
 173           return 1;
 174         }
 175
 176       if (*p != 1)
 177         {
 178           puts ("*p != 1");
 179           return 1;
 180         }
 181
 182       puts ("parent done");
 183     }
 184
 185   return 0;
 186 }
 187
 188 #define TEST_FUNCTION do_test ()
 189 #include "../test-skeleton.c"