gthread: avoid locking in _get_mutex_impl

When getting the mutex implementation of a static mutex, avoid taking the global
lock every time but only take the lock when there was no mutex and we need to
create one.

https://bugzilla.gnome.org/show_bug.cgi?id=599954
This commit is contained in:
Wim Taymans 2009-09-16 17:39:48 +02:00 committed by Matthias Clasen
parent fca330dafa
commit 496157ffd3

View File

@ -1267,19 +1267,30 @@ g_static_mutex_init (GStaticMutex *mutex)
GMutex *
g_static_mutex_get_mutex_impl (GMutex** mutex)
{
GMutex *result;
if (!g_thread_supported ())
return NULL;
g_assert (g_once_mutex);
result = g_atomic_pointer_get (mutex);
g_mutex_lock (g_once_mutex);
if (!result)
{
g_assert (g_once_mutex);
if (!(*mutex))
g_atomic_pointer_set (mutex, g_mutex_new());
g_mutex_lock (g_once_mutex);
g_mutex_unlock (g_once_mutex);
result = *mutex;
if (!result)
{
result = g_mutex_new ();
g_atomic_pointer_set (mutex, result);
}
return *mutex;
g_mutex_unlock (g_once_mutex);
}
return result;
}
/* IMPLEMENTATION NOTE: