Drop old semaphore implementation

- Removed platform-specific implementations.
- Now all semaphores are in-object, unless they need to be conditionally created.
- Similarly to `Mutex`, provided a dummy implementation for when `NO_THREADS` is defined.
- Similarly to `Mutex`, methods are made `const` for easy use in such contexts.
- Language bindings updated: `wait()` and `post()` are now `void`.
- Language bindings updated: `try_wait()` added.

Bonus:
- Rewritten the `#ifdef` in `mutex.h` to meet the code style.

2 files changed, 5 insertions, 12 deletions

diff --git a/servers/physics_2d/physics_2d_server_wrap_mt.cpp b/servers/physics_2d/physics_2d_server_wrap_mt.cpp
index 7070902f77..76036930c6 100644
--- a/servers/physics_2d/physics_2d_server_wrap_mt.cpp
+++ b/servers/physics_2d/physics_2d_server_wrap_mt.cpp
@@ -40,7 +40,7 @@ void Physics2DServerWrapMT::thread_exit() {
 void Physics2DServerWrapMT::thread_step(real_t p_delta) {
 
 	physics_2d_server->step(p_delta);
-	step_sem->post();
+	step_sem.post();
 }
 
 void Physics2DServerWrapMT::_thread_callback(void *_instance) {
@@ -84,11 +84,11 @@ void Physics2DServerWrapMT::step(real_t p_step) {
 
 void Physics2DServerWrapMT::sync() {
 
-	if (step_sem) {
+	if (thread) {
 		if (first_frame)
 			first_frame = false;
 		else
-			step_sem->wait(); //must not wait if a step was not issued
+			step_sem.wait(); //must not wait if a step was not issued
 	}
 	physics_2d_server->sync();
 }
@@ -107,11 +107,8 @@ void Physics2DServerWrapMT::init() {
 
 	if (create_thread) {
 
-		step_sem = SemaphoreOld::create();
 		//OS::get_singleton()->release_rendering_thread();
-		if (create_thread) {
-			thread = Thread::create(_thread_callback, this);
-		}
+		thread = Thread::create(_thread_callback, this);
 		while (!step_thread_up) {
 			OS::get_singleton()->delay_usec(1000);
 		}
@@ -146,9 +143,6 @@ void Physics2DServerWrapMT::finish() {
 	space_free_cached_ids();
 	area_free_cached_ids();
 	body_free_cached_ids();
-
-	if (step_sem)
-		memdelete(step_sem);
 }
 
 Physics2DServerWrapMT::Physics2DServerWrapMT(Physics2DServer *p_contained, bool p_create_thread) :
@@ -157,7 +151,6 @@ Physics2DServerWrapMT::Physics2DServerWrapMT(Physics2DServer *p_contained, bool
 	physics_2d_server = p_contained;
 	create_thread = p_create_thread;
 	thread = NULL;
-	step_sem = NULL;
 	step_pending = 0;
 	step_thread_up = false;
 
diff --git a/servers/physics_2d/physics_2d_server_wrap_mt.h b/servers/physics_2d/physics_2d_server_wrap_mt.h
index 0648b8651f..4d5e317c8c 100644
--- a/servers/physics_2d/physics_2d_server_wrap_mt.h
+++ b/servers/physics_2d/physics_2d_server_wrap_mt.h
@@ -58,7 +58,7 @@ class Physics2DServerWrapMT : public Physics2DServer {
 	volatile bool step_thread_up;
 	bool create_thread;
 
-	SemaphoreOld *step_sem;
+	Semaphore step_sem;
 	int step_pending;
 	void thread_step(real_t p_delta);
 	void thread_flush();