Use WorkerThreadPool for Server threads

* Servers now use WorkerThreadPool for background computation. * This helps keep the number of threads used fixed at all times. * It also ensures everything works on HTML5 with threads. * And makes it easier to support disabling threads for also HTML5. The only downside of this is that GLES3 threads likely no longer work because every time the render thread is called, the thread context is different. This needs to be researched how to fix. Maybe if GLES3 is used, threaded rendering server should be disabled for the time being?
godotengine · May 12, 2023 · d2efed2 · d2efed2
1 parent 20ed51a
commit d2efed2
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Showing 6 changed files with 55 additions and 201 deletions.
diff --git a/servers/physics_server_2d_wrap_mt.cpp b/servers/physics_server_2d_wrap_mt.cpp
@@ -32,43 +32,18 @@
 
 #include "core/os/os.h"
 
-void PhysicsServer2DWrapMT::thread_exit() {
-	exit.set();
-}
-
 void PhysicsServer2DWrapMT::thread_step(real_t p_delta) {
-	physics_server_2d->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_server_2d->init();
-
-	exit.clear();
-	step_thread_up.set();
-	while (!exit.is_set()) {
-		// flush commands one by one, until exit is requested
-		command_queue.wait_and_flush();
-	}
-
-	command_queue.flush_all(); // flush all
-
-	physics_server_2d->finish();
+	physics_server_2d->step(p_delta);
+	command_queue.flush_all();
+	server_thread = Thread::UNASSIGNED_ID;
 }
 
 /* EVENT QUEUING */
 
 void PhysicsServer2DWrapMT::step(real_t p_step) {
 	if (create_thread) {
-		command_queue.push(this, &PhysicsServer2DWrapMT::thread_step, p_step);
+		task_id = WorkerThreadPool::get_singleton()->add_task(callable_mp(this, &PhysicsServer2DWrapMT::thread_step).bind(p_step), true);
 	} else {
 		command_queue.flush_all(); //flush all pending from other threads
 		physics_server_2d->step(p_step);
@@ -77,10 +52,9 @@ void PhysicsServer2DWrapMT::step(real_t p_step) {
 
 void PhysicsServer2DWrapMT::sync() {
 	if (create_thread) {
-		if (first_frame) {
-			first_frame = false;
-		} else {
-			step_sem.wait(); //must not wait if a step was not issued
+		if (task_id != WorkerThreadPool::INVALID_TASK_ID) {
+			WorkerThreadPool::get_singleton()->wait_for_task_completion(task_id);
+			task_id = WorkerThreadPool::INVALID_TASK_ID;
 		}
 	}
 	physics_server_2d->sync();
@@ -95,24 +69,15 @@ void PhysicsServer2DWrapMT::end_sync() {
 }
 
 void PhysicsServer2DWrapMT::init() {
-	if (create_thread) {
-		//OS::get_singleton()->release_rendering_thread();
-		thread.start(_thread_callback, this);
-		while (!step_thread_up.is_set()) {
-			OS::get_singleton()->delay_usec(1000);
-		}
-	} else {
-		physics_server_2d->init();
-	}
+	physics_server_2d->init();
 }
 
 void PhysicsServer2DWrapMT::finish() {
-	if (thread.is_started()) {
-		command_queue.push(this, &PhysicsServer2DWrapMT::thread_exit);
-		thread.wait_to_finish();
-	} else {
-		physics_server_2d->finish();
+	if (task_id != WorkerThreadPool::INVALID_TASK_ID) {
+		WorkerThreadPool::get_singleton()->wait_for_task_completion(task_id);
+		task_id = WorkerThreadPool::INVALID_TASK_ID;
 	}
+	physics_server_2d->finish();
 }
 
 PhysicsServer2DWrapMT::PhysicsServer2DWrapMT(PhysicsServer2D *p_contained, bool p_create_thread) :
@@ -123,12 +88,12 @@ PhysicsServer2DWrapMT::PhysicsServer2DWrapMT(PhysicsServer2D *p_contained, bool
 	pool_max_size = GLOBAL_GET("memory/limits/multithreaded_server/rid_pool_prealloc");
 
 	if (!p_create_thread) {
-		server_thread = Thread::get_caller_id();
+		server_thread = Thread::MAIN_ID;
 	} else {
-		server_thread = 0;
+		server_thread = Thread::UNASSIGNED_ID;
 	}
 
-	main_thread = Thread::get_caller_id();
+	main_thread = Thread::MAIN_ID;
 }
 
 PhysicsServer2DWrapMT::~PhysicsServer2DWrapMT() {

diff --git a/servers/physics_server_2d_wrap_mt.h b/servers/physics_server_2d_wrap_mt.h
@@ -32,6 +32,7 @@
 #define PHYSICS_SERVER_2D_WRAP_MT_H
 
 #include "core/config/project_settings.h"
+#include "core/object/worker_thread_pool.h"
 #include "core/os/thread.h"
 #include "core/templates/command_queue_mt.h"
 #include "core/templates/safe_refcount.h"
@@ -49,23 +50,14 @@ class PhysicsServer2DWrapMT : public PhysicsServer2D {
 	mutable CommandQueueMT command_queue;
 
 	static void _thread_callback(void *_instance);
-	void thread_loop();
 
 	Thread::ID server_thread;
 	Thread::ID main_thread;
-	SafeFlag exit;
-	Thread thread;
-	SafeFlag step_thread_up;
 	bool create_thread = false;
+	WorkerThreadPool::TaskID task_id = WorkerThreadPool::INVALID_TASK_ID;
 
-	Semaphore step_sem;
 	void thread_step(real_t p_delta);
 
-	void thread_exit();
-
-	bool first_frame = true;
-
-	Mutex alloc_mutex;
 	int pool_max_size = 0;
 
 public:

diff --git a/servers/physics_server_3d_wrap_mt.cpp b/servers/physics_server_3d_wrap_mt.cpp
@@ -32,43 +32,18 @@
 
 #include "core/os/os.h"
 
-void PhysicsServer3DWrapMT::thread_exit() {
-	exit = true;
-}
-
 void PhysicsServer3DWrapMT::thread_step(real_t p_delta) {
-	physics_server_3d->step(p_delta);
-	step_sem.post();
-}
-
-void PhysicsServer3DWrapMT::_thread_callback(void *_instance) {
-	PhysicsServer3DWrapMT *vsmt = reinterpret_cast<PhysicsServer3DWrapMT *>(_instance);
-
-	vsmt->thread_loop();
-}
-
-void PhysicsServer3DWrapMT::thread_loop() {
 	server_thread = Thread::get_caller_id();
-
-	physics_server_3d->init();
-
-	exit = false;
-	step_thread_up = true;
-	while (!exit) {
-		// flush commands one by one, until exit is requested
-		command_queue.wait_and_flush();
-	}
-
-	command_queue.flush_all(); // flush all
-
-	physics_server_3d->finish();
+	physics_server_3d->step(p_delta);
+	command_queue.flush_all();
+	server_thread = Thread::UNASSIGNED_ID;
 }
 
 /* EVENT QUEUING */
 
 void PhysicsServer3DWrapMT::step(real_t p_step) {
 	if (create_thread) {
-		command_queue.push(this, &PhysicsServer3DWrapMT::thread_step, p_step);
+		task_id = WorkerThreadPool::get_singleton()->add_task(callable_mp(this, &PhysicsServer3DWrapMT::thread_step).bind(p_step), true);
 	} else {
 		command_queue.flush_all(); //flush all pending from other threads
 		physics_server_3d->step(p_step);
@@ -77,10 +52,9 @@ void PhysicsServer3DWrapMT::step(real_t p_step) {
 
 void PhysicsServer3DWrapMT::sync() {
 	if (create_thread) {
-		if (first_frame) {
-			first_frame = false;
-		} else {
-			step_sem.wait(); //must not wait if a step was not issued
+		if (task_id != WorkerThreadPool::INVALID_TASK_ID) {
+			WorkerThreadPool::get_singleton()->wait_for_task_completion(task_id);
+			task_id = WorkerThreadPool::INVALID_TASK_ID;
 		}
 	}
 	physics_server_3d->sync();
@@ -95,24 +69,15 @@ void PhysicsServer3DWrapMT::end_sync() {
 }
 
 void PhysicsServer3DWrapMT::init() {
-	if (create_thread) {
-		//OS::get_singleton()->release_rendering_thread();
-		thread.start(_thread_callback, this);
-		while (!step_thread_up) {
-			OS::get_singleton()->delay_usec(1000);
-		}
-	} else {
-		physics_server_3d->init();
-	}
+	physics_server_3d->init();
 }
 
 void PhysicsServer3DWrapMT::finish() {
-	if (thread.is_started()) {
-		command_queue.push(this, &PhysicsServer3DWrapMT::thread_exit);
-		thread.wait_to_finish();
-	} else {
-		physics_server_3d->finish();
+	if (task_id != WorkerThreadPool::INVALID_TASK_ID) {
+		WorkerThreadPool::get_singleton()->wait_for_task_completion(task_id);
+		task_id = WorkerThreadPool::INVALID_TASK_ID;
 	}
+	physics_server_3d->finish();
 }
 
 PhysicsServer3DWrapMT::PhysicsServer3DWrapMT(PhysicsServer3D *p_contained, bool p_create_thread) :
@@ -123,12 +88,12 @@ PhysicsServer3DWrapMT::PhysicsServer3DWrapMT(PhysicsServer3D *p_contained, bool
 	pool_max_size = GLOBAL_GET("memory/limits/multithreaded_server/rid_pool_prealloc");
 
 	if (!p_create_thread) {
-		server_thread = Thread::get_caller_id();
+		server_thread = Thread::MAIN_ID;
 	} else {
-		server_thread = 0;
+		server_thread = Thread::UNASSIGNED_ID;
 	}
 
-	main_thread = Thread::get_caller_id();
+	main_thread = Thread::MAIN_ID;
 }
 
 PhysicsServer3DWrapMT::~PhysicsServer3DWrapMT() {

diff --git a/servers/physics_server_3d_wrap_mt.h b/servers/physics_server_3d_wrap_mt.h
@@ -32,6 +32,7 @@
 #define PHYSICS_SERVER_3D_WRAP_MT_H
 
 #include "core/config/project_settings.h"
+#include "core/object/worker_thread_pool.h"
 #include "core/os/thread.h"
 #include "core/templates/command_queue_mt.h"
 #include "servers/physics_server_3d.h"
@@ -48,23 +49,14 @@ class PhysicsServer3DWrapMT : public PhysicsServer3D {
 	mutable CommandQueueMT command_queue;
 
 	static void _thread_callback(void *_instance);
-	void thread_loop();
 
 	Thread::ID server_thread;
 	Thread::ID main_thread;
-	volatile bool exit = false;
-	Thread thread;
-	volatile bool step_thread_up = false;
 	bool create_thread = false;
+	WorkerThreadPool::TaskID task_id = WorkerThreadPool::INVALID_TASK_ID;
 
-	Semaphore step_sem;
 	void thread_step(real_t p_delta);
 
-	void thread_exit();
-
-	bool first_frame = true;
-
-	Mutex alloc_mutex;
 	int pool_max_size = 0;
 
 public: