[4.3] Cherry-picks related to ResourceLoader

core/io/resource.cpp

@@ -40,12 +40,12 @@
 #include <stdio.h>
 
 void Resource::emit_changed() {
-	if (ResourceLoader::is_within_load() && MessageQueue::get_main_singleton() != MessageQueue::get_singleton() && !MessageQueue::get_singleton()->is_flushing()) {
-		// Let the connection happen on the call queue, later, since signals are not thread-safe.
-		call_deferred("emit_signal", CoreStringName(changed));
-	} else {
-		emit_signal(CoreStringName(changed));
+	if (ResourceLoader::is_within_load() && !Thread::is_main_thread()) {
+		ResourceLoader::resource_changed_emit(this);
+		return;
 	}
+
+	emit_signal(CoreStringName(changed));
 }
 
 void Resource::_resource_path_changed() {
@@ -166,22 +166,22 @@ bool Resource::editor_can_reload_from_file() {
 }
 
 void Resource::connect_changed(const Callable &p_callable, uint32_t p_flags) {
-	if (ResourceLoader::is_within_load() && MessageQueue::get_main_singleton() != MessageQueue::get_singleton() && !MessageQueue::get_singleton()->is_flushing()) {
-		// Let the check and connection happen on the call queue, later, since signals are not thread-safe.
-		callable_mp(this, &Resource::connect_changed).call_deferred(p_callable, p_flags);
+	if (ResourceLoader::is_within_load() && !Thread::is_main_thread()) {
+		ResourceLoader::resource_changed_connect(this, p_callable, p_flags);
 		return;
 	}
+
 	if (!is_connected(CoreStringName(changed), p_callable) || p_flags & CONNECT_REFERENCE_COUNTED) {
 		connect(CoreStringName(changed), p_callable, p_flags);
 	}
 }
 
 void Resource::disconnect_changed(const Callable &p_callable) {
-	if (ResourceLoader::is_within_load() && MessageQueue::get_main_singleton() != MessageQueue::get_singleton() && !MessageQueue::get_singleton()->is_flushing()) {
-		// Let the check and disconnection happen on the call queue, later, since signals are not thread-safe.
-		callable_mp(this, &Resource::disconnect_changed).call_deferred(p_callable);
+	if (ResourceLoader::is_within_load() && !Thread::is_main_thread()) {
+		ResourceLoader::resource_changed_disconnect(this, p_callable);
 		return;
 	}
+
 	if (is_connected(CoreStringName(changed), p_callable)) {
 		disconnect(CoreStringName(changed), p_callable);
 	}