+MonoBoolean mono_monitor_enter_internal (MonoObject *obj);
+void mono_monitor_enter_v4_internal (MonoObject *obj, MonoBoolean *lock_taken);
+
+guint32 mono_monitor_enter_fast (MonoObject *obj);
+guint32 mono_monitor_enter_v4_fast (MonoObject *obj, MonoBoolean *lock_taken);
+