Add regression test for GWeakRef used to cache a singleton

https://bugzilla.gnome.org/show_bug.cgi?id=548954
This commit is contained in:
Simon McVittie 2011-12-07 15:04:13 +00:00 committed by Ryan Lortie
parent fa5ff39559
commit 146aa7aa17

View File

@ -204,6 +204,126 @@ test_threaded_object_init (void)
g_thread_join (creator);
}
typedef struct {
MyTester0 *strong;
guint unref_delay;
} UnrefInThreadData;
static gpointer
unref_in_thread (gpointer p)
{
UnrefInThreadData *data = p;
g_usleep (data->unref_delay);
g_object_unref (data->strong);
return NULL;
}
/* undefine to see this test fail without GWeakRef */
#define HAVE_G_WEAK_REF
#define SLEEP_MIN_USEC 1
#define SLEEP_MAX_USEC 10
static void
test_threaded_weak_ref (void)
{
guint i;
guint get_wins = 0, unref_wins = 0;
guint n;
if (g_test_thorough ())
n = NUM_COUNTER_INCREMENTS;
else
n = NUM_COUNTER_INCREMENTS / 20;
for (i = 0; i < n; i++)
{
UnrefInThreadData data;
#ifdef HAVE_G_WEAK_REF
/* GWeakRef<MyTester0> in C++ terms */
GWeakRef weak;
#else
gpointer weak;
#endif
MyTester0 *strengthened;
guint get_delay;
GThread *thread;
GError *error = NULL;
if (g_test_verbose () && (i % (n/20)) == 0)
g_print ("%u%%\n", ((i * 100) / n));
/* Have an object and a weak ref to it */
data.strong = g_object_new (my_tester0_get_type (), NULL);
#ifdef HAVE_G_WEAK_REF
g_weak_ref_init (&weak, data.strong);
#else
weak = data.strong;
g_object_add_weak_pointer ((GObject *) weak, &weak);
#endif
/* Delay for a random time on each side of the race, to perturb the
* timing. Ideally, we want each side to win half the races; on
* smcv's laptop, these timings are about right.
*/
data.unref_delay = g_random_int_range (SLEEP_MIN_USEC / 2, SLEEP_MAX_USEC / 2);
get_delay = g_random_int_range (SLEEP_MIN_USEC, SLEEP_MAX_USEC);
/* One half of the race is to unref the shared object */
thread = g_thread_create (unref_in_thread, &data, TRUE, &error);
g_assert_no_error (error);
/* The other half of the race is to get the object from the "global
* singleton"
*/
g_usleep (get_delay);
#ifdef HAVE_G_WEAK_REF
strengthened = g_weak_ref_get (&weak);
#else
/* Spot the unsafe pointer access! In GDBusConnection this is rather
* better-hidden, but ends up with essentially the same thing, albeit
* cleared in dispose() rather than by a traditional weak pointer
*/
strengthened = weak;
if (strengthened != NULL)
g_object_ref (strengthened);
#endif
if (strengthened != NULL)
g_assert (G_IS_OBJECT (strengthened));
/* Wait for the thread to run */
g_thread_join (thread);
if (strengthened != NULL)
{
get_wins++;
g_assert (G_IS_OBJECT (strengthened));
g_object_unref (strengthened);
}
else
{
unref_wins++;
}
#ifdef HAVE_G_WEAK_REF
g_weak_ref_clear (&weak);
#else
if (weak != NULL)
g_object_remove_weak_pointer (weak, &weak);
#endif
}
if (g_test_verbose ())
g_print ("Race won by get %u times, unref %u times\n",
get_wins, unref_wins);
}
int
main (int argc,
char *argv[])
@ -213,6 +333,7 @@ main (int argc,
g_test_add_func ("/GObject/threaded-class-init", test_threaded_class_init);
g_test_add_func ("/GObject/threaded-object-init", test_threaded_object_init);
g_test_add_func ("/GObject/threaded-weak-ref", test_threaded_weak_ref);
return g_test_run();
}