Renaming of servers for coherency.

VisualServer -> RenderingServer
PhysicsServer -> PhysicsServer3D
Physics2DServer -> PhysicsServer2D
NavigationServer -> NavigationServer3D
Navigation2DServer -> NavigationServer2D

Also renamed corresponding files.

servers/physics_2d/physics_server_2d_wrap_mt.cpp

@@ -0,0 +1,173 @@
+/*************************************************************************/
+/*  physics_2d_server_wrap_mt.cpp                                        */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "physics_server_2d_wrap_mt.h"
+
+#include "core/os/os.h"
+
+void PhysicsServer2DWrapMT::thread_exit() {
+
+	exit = true;
+}
+
+void PhysicsServer2DWrapMT::thread_step(real_t p_delta) {
+
+	physics_2d_server->step(p_delta);
+	step_sem.post();
+}
+
+void PhysicsServer2DWrapMT::_thread_callback(void *_instance) {
+
+	PhysicsServer2DWrapMT *vsmt = reinterpret_cast<PhysicsServer2DWrapMT *>(_instance);
+
+	vsmt->thread_loop();
+}
+
+void PhysicsServer2DWrapMT::thread_loop() {
+
+	server_thread = Thread::get_caller_id();
+
+	physics_2d_server->init();
+
+	exit = false;
+	step_thread_up = true;
+	while (!exit) {
+		// flush commands one by one, until exit is requested
+		command_queue.wait_and_flush_one();
+	}
+
+	command_queue.flush_all(); // flush all
+
+	physics_2d_server->finish();
+}
+
+/* EVENT QUEUING */
+
+void PhysicsServer2DWrapMT::step(real_t p_step) {
+
+	if (create_thread) {
+
+		command_queue.push(this, &PhysicsServer2DWrapMT::thread_step, p_step);
+	} else {
+
+		command_queue.flush_all(); //flush all pending from other threads
+		physics_2d_server->step(p_step);
+	}
+}
+
+void PhysicsServer2DWrapMT::sync() {
+
+	if (thread) {
+		if (first_frame)
+			first_frame = false;
+		else
+			step_sem.wait(); //must not wait if a step was not issued
+	}
+	physics_2d_server->sync();
+}
+
+void PhysicsServer2DWrapMT::flush_queries() {
+
+	physics_2d_server->flush_queries();
+}
+
+void PhysicsServer2DWrapMT::end_sync() {
+
+	physics_2d_server->end_sync();
+}
+
+void PhysicsServer2DWrapMT::init() {
+
+	if (create_thread) {
+
+		//OS::get_singleton()->release_rendering_thread();
+		thread = Thread::create(_thread_callback, this);
+		while (!step_thread_up) {
+			OS::get_singleton()->delay_usec(1000);
+		}
+	} else {
+
+		physics_2d_server->init();
+	}
+}
+
+void PhysicsServer2DWrapMT::finish() {
+
+	if (thread) {
+
+		command_queue.push(this, &PhysicsServer2DWrapMT::thread_exit);
+		Thread::wait_to_finish(thread);
+		memdelete(thread);
+
+		thread = NULL;
+	} else {
+		physics_2d_server->finish();
+	}
+
+	line_shape_free_cached_ids();
+	ray_shape_free_cached_ids();
+	segment_shape_free_cached_ids();
+	circle_shape_free_cached_ids();
+	rectangle_shape_free_cached_ids();
+	capsule_shape_free_cached_ids();
+	convex_polygon_shape_free_cached_ids();
+	concave_polygon_shape_free_cached_ids();
+
+	space_free_cached_ids();
+	area_free_cached_ids();
+	body_free_cached_ids();
+}
+
+PhysicsServer2DWrapMT::PhysicsServer2DWrapMT(PhysicsServer2D *p_contained, bool p_create_thread) :
+		command_queue(p_create_thread) {
+
+	physics_2d_server = p_contained;
+	create_thread = p_create_thread;
+	thread = NULL;
+	step_pending = 0;
+	step_thread_up = false;
+
+	pool_max_size = GLOBAL_GET("memory/limits/multithreaded_server/rid_pool_prealloc");
+
+	if (!p_create_thread) {
+		server_thread = Thread::get_caller_id();
+	} else {
+		server_thread = 0;
+	}
+
+	main_thread = Thread::get_caller_id();
+	first_frame = true;
+}
+
+PhysicsServer2DWrapMT::~PhysicsServer2DWrapMT() {
+
+	memdelete(physics_2d_server);
+	//finish();
+}