glib/tests/642026.c

   1 /*
   2  * Author: Simon McVittie <simon.mcvittie@collabora.co.uk>
   3  * Copyright © 2011 Nokia Corporation
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser 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  * See the included COPYING file for more information.
  11  */
  12
  13 #define GLIB_DISABLE_DEPRECATION_WARNINGS
  14
  15 #include <glib.h>
  16
  17 /* On smcv's laptop, 1e4 iterations didn't always exhibit the bug, but 1e5
  18  * iterations exhibited it 10/10 times in practice. YMMV. */
  19 #define ITERATIONS 100000
  20
  21 static GStaticPrivate sp;
  22 static GMutex *mutex;
  23 static GCond *cond;
  24 static guint i;
  25
  26 static volatile gint freed = 0;
  27
  28 static void
  29 notify (gpointer p)
  30 {
  31   if (!g_atomic_int_compare_and_exchange (&freed, 0, 1))
  32     {
  33       g_error ("someone already freed it after %u iterations", i);
  34     }
  35 }
  36
  37 static gpointer thread_func (gpointer nil)
  38 {
  39   /* wait for main thread to reach its g_cond_wait call */
  40   g_mutex_lock (mutex);
  41
  42   g_static_private_set (&sp, &sp, notify);
  43   g_cond_broadcast (cond);
  44   g_mutex_unlock (mutex);
  45
  46   return nil;
  47 }
  48
  49 static void
  50 testcase (void)
  51 {
  52   g_test_bug ("642026");
  53
  54   mutex = g_mutex_new ();
  55   cond = g_cond_new ();
  56
  57   g_mutex_lock (mutex);
  58
  59   for (i = 0; i < ITERATIONS; i++)
  60     {
  61       GThread *t1;
  62
  63       g_static_private_init (&sp);
  64       freed = 0;
  65
  66       t1 = g_thread_create (thread_func, NULL, TRUE, NULL);
  67
  68       /* wait for t1 to set up its thread-private data */
  69       g_cond_wait (cond, mutex);
  70
  71       /* exercise the bug, by racing with t1 to free the private data */
  72       g_static_private_free (&sp);
  73       g_thread_join (t1);
  74     }
  75
  76   g_cond_free (cond);
  77   g_mutex_unlock (mutex);
  78   g_mutex_free (mutex);
  79 }
  80
  81 int
  82 main (int argc,
  83     char **argv)
  84 {
  85   g_test_init (&argc, &argv, NULL);
  86   g_test_bug_base ("https://bugzilla.gnome.org/show_bug.cgi?id=");
  87
  88   g_test_add_func ("/glib/642026", testcase);
  89
  90   return g_test_run ();
  91 }