[RichTextLabel] Fix thread unsafe `set_physics_process_internal` usage. Use `WorkerThreadPool` instead of creating new threads.

modules/text_server_adv/text_server_adv.cpp

@@ -4068,7 +4068,6 @@ void TextServerAdvanced::_realign(ShapedTextDataAdvanced *p_sd) const {
 
 RID TextServerAdvanced::_shaped_text_substr(const RID &p_shaped, int64_t p_start, int64_t p_length) const {
 	_THREAD_SAFE_METHOD_
-
 	const ShapedTextDataAdvanced *sd = shaped_owner.get_or_null(p_shaped);
 	ERR_FAIL_COND_V(!sd, RID());
 
@@ -5513,6 +5512,7 @@ void TextServerAdvanced::_shape_run(ShapedTextDataAdvanced *p_sd, int64_t p_star
 }
 
 bool TextServerAdvanced::_shaped_text_shape(const RID &p_shaped) {
+	_THREAD_SAFE_METHOD_
 	ShapedTextDataAdvanced *sd = shaped_owner.get_or_null(p_shaped);
 	ERR_FAIL_COND_V(!sd, false);
 
@@ -6569,6 +6569,7 @@ TextServerAdvanced::TextServerAdvanced() {
 }
 
 void TextServerAdvanced::_cleanup() {
+	_THREAD_SAFE_METHOD_
 	for (const KeyValue<SystemFontKey, SystemFontCache> &E : system_fonts) {
 		const Vector<SystemFontCacheRec> &sysf_cache = E.value.var;
 		for (const SystemFontCacheRec &F : sysf_cache) {

scene/gui/rich_text_label.cpp

@@ -1797,7 +1797,9 @@ void RichTextLabel::_notification(int p_what) {
 		} break;
 
 		case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
-			queue_redraw();
+			if (is_visible_in_tree()) {
+				queue_redraw();
+			}
 		} break;
 
 		case NOTIFICATION_DRAW: {
@@ -2665,19 +2667,26 @@ bool RichTextLabel::_find_layout_subitem(Item *from, Item *to) {
 	return false;
 }
 
-void RichTextLabel::_thread_function(void *self) {
-	RichTextLabel *rtl = reinterpret_cast<RichTextLabel *>(self);
-	rtl->set_physics_process_internal(true);
-	rtl->_process_line_caches();
-	rtl->set_physics_process_internal(false);
-	rtl->updating.store(false);
-	rtl->call_deferred(SNAME("queue_redraw"));
+void RichTextLabel::_thread_function(void *p_userdata) {
+	_process_line_caches();
+	updating.store(false);
+	call_deferred(SNAME("thread_end"));
+}
+
+void RichTextLabel::_thread_end() {
+	set_physics_process_internal(false);
+	if (is_visible_in_tree()) {
+		queue_redraw();
+	}
 }
 
 void RichTextLabel::_stop_thread() {
 	if (threaded) {
 		stop_thread.store(true);
-		thread.wait_to_finish();
+		if (task != WorkerThreadPool::INVALID_TASK_ID) {
+			WorkerThreadPool::get_singleton()->wait_for_task_completion(task);
+			task = WorkerThreadPool::INVALID_TASK_ID;
+		}
 	}
 }
 
@@ -2787,7 +2796,8 @@ bool RichTextLabel::_validate_line_caches() {
 	if (threaded) {
 		updating.store(true);
 		loaded.store(true);
-		thread.start(RichTextLabel::_thread_function, reinterpret_cast<void *>(this));
+		task = WorkerThreadPool::get_singleton()->add_template_task(this, &RichTextLabel::_thread_function, nullptr, true, vformat("RichTextLabelShape:%x", (int64_t)get_instance_id()));
+		set_physics_process_internal(true);
 		loading_started = OS::get_singleton()->get_ticks_msec();
 		return false;
 	} else {
@@ -5457,6 +5467,8 @@ void RichTextLabel::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_menu"), &RichTextLabel::get_menu);
 	ClassDB::bind_method(D_METHOD("is_menu_visible"), &RichTextLabel::is_menu_visible);
 
+	ClassDB::bind_method(D_METHOD("_thread_end"), &RichTextLabel::_thread_end);
+
 	// Note: set "bbcode_enabled" first, to avoid unnecessary "text" resets.
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "bbcode_enabled"), "set_use_bbcode", "is_using_bbcode");
 	ADD_PROPERTY(PropertyInfo(Variant::STRING, "text", PROPERTY_HINT_MULTILINE_TEXT), "set_text", "get_text");

scene/gui/rich_text_label.h

@@ -31,6 +31,7 @@
 #ifndef RICH_TEXT_LABEL_H
 #define RICH_TEXT_LABEL_H
 
+#include "core/object/worker_thread_pool.h"
 #include "rich_text_effect.h"
 #include "scene/gui/popup_menu.h"
 #include "scene/gui/scroll_bar.h"
@@ -369,7 +370,7 @@ private:
 	Item *current = nullptr;
 	ItemFrame *current_frame = nullptr;
 
-	Thread thread;
+	WorkerThreadPool::TaskID task = WorkerThreadPool::INVALID_TASK_ID;
 	Mutex data_mutex;
 	bool threaded = false;
 	std::atomic<bool> stop_thread;
@@ -409,7 +410,8 @@ private:
 
 	void _invalidate_current_line(ItemFrame *p_frame);
 
-	static void _thread_function(void *self);
+	void _thread_function(void *p_userdata);
+	void _thread_end();
 	void _stop_thread();
 	bool _validate_line_caches();
 	void _process_line_caches();