Merge pull request #36752 from RandomShaper/rework_semaphore

Drop old semaphore implementation

33 files changed, 79 insertions, 803 deletions

diff --git a/core/bind/core_bind.cpp b/core/bind/core_bind.cpp
index 264d8d415c..bfe07d61c5 100644
--- a/core/bind/core_bind.cpp
+++ b/core/bind/core_bind.cpp
@@ -2576,30 +2576,26 @@ void _Marshalls::_bind_methods() {
 
 ////////////////
 
-Error _Semaphore::wait() {
+void _Semaphore::wait() {
 
-	return semaphore->wait();
+	semaphore.wait();
 }
 
-Error _Semaphore::post() {
+Error _Semaphore::try_wait() {
 
-	return semaphore->post();
+	return semaphore.try_wait() ? OK : ERR_BUSY;
 }
 
-void _Semaphore::_bind_methods() {
+void _Semaphore::post() {
 
-	ClassDB::bind_method(D_METHOD("wait"), &_Semaphore::wait);
-	ClassDB::bind_method(D_METHOD("post"), &_Semaphore::post);
+	semaphore.post();
 }
 
-_Semaphore::_Semaphore() {
-
-	semaphore = SemaphoreOld::create();
-}
-
-_Semaphore::~_Semaphore() {
+void _Semaphore::_bind_methods() {
 
-	memdelete(semaphore);
+	ClassDB::bind_method(D_METHOD("wait"), &_Semaphore::wait);
+	ClassDB::bind_method(D_METHOD("try_wait"), &_Semaphore::try_wait);
+	ClassDB::bind_method(D_METHOD("post"), &_Semaphore::post);
 }
 
 ///////////////
diff --git a/core/bind/core_bind.h b/core/bind/core_bind.h
index e7850de744..fc6419b7d8 100644
--- a/core/bind/core_bind.h
+++ b/core/bind/core_bind.h
@@ -635,16 +635,14 @@ public:
 class _Semaphore : public Reference {
 
 	GDCLASS(_Semaphore, Reference);
-	SemaphoreOld *semaphore;
+	Semaphore semaphore;
 
 	static void _bind_methods();
 
 public:
-	Error wait();
-	Error post();
-
-	_Semaphore();
-	~_Semaphore();
+	void wait();
+	Error try_wait();
+	void post();
 };
 
 class _Thread : public Reference {
diff --git a/core/command_queue_mt.cpp b/core/command_queue_mt.cpp
index b88f773ed8..85e8a847a0 100644
--- a/core/command_queue_mt.cpp
+++ b/core/command_queue_mt.cpp
@@ -108,11 +108,10 @@ CommandQueueMT::CommandQueueMT(bool p_sync) {
 
 	for (int i = 0; i < SYNC_SEMAPHORES; i++) {
 
-		sync_sems[i].sem = SemaphoreOld::create();
 		sync_sems[i].in_use = false;
 	}
 	if (p_sync)
-		sync = SemaphoreOld::create();
+		sync = memnew(Semaphore);
 	else
 		sync = NULL;
 }
@@ -121,9 +120,5 @@ CommandQueueMT::~CommandQueueMT() {
 
 	if (sync)
 		memdelete(sync);
-	for (int i = 0; i < SYNC_SEMAPHORES; i++) {
-
-		memdelete(sync_sems[i].sem);
-	}
 	memfree(command_mem);
 }
diff --git a/core/command_queue_mt.h b/core/command_queue_mt.h
index 7407557e7e..90231546ef 100644
--- a/core/command_queue_mt.h
+++ b/core/command_queue_mt.h
@@ -270,7 +270,7 @@
 		cmd->sync_sem = ss;                                                                    \
 		unlock();                                                                              \
 		if (sync) sync->post();                                                                \
-		ss->sem->wait();                                                                       \
+		ss->sem.wait();                                                                        \
 		ss->in_use = false;                                                                    \
 	}
 
@@ -287,7 +287,7 @@
 		cmd->sync_sem = ss;                                                           \
 		unlock();                                                                     \
 		if (sync) sync->post();                                                       \
-		ss->sem->wait();                                                              \
+		ss->sem.wait();                                                               \
 		ss->in_use = false;                                                           \
 	}
 
@@ -297,7 +297,7 @@ class CommandQueueMT {
 
 	struct SyncSemaphore {
 
-		SemaphoreOld *sem;
+		Semaphore sem;
 		bool in_use;
 	};
 
@@ -313,7 +313,7 @@ class CommandQueueMT {
 		SyncSemaphore *sync_sem;
 
 		virtual void post() {
-			sync_sem->sem->post();
+			sync_sem->sem.post();
 		}
 	};
 
@@ -342,7 +342,7 @@ class CommandQueueMT {
 	uint32_t dealloc_ptr;
 	SyncSemaphore sync_sems[SYNC_SEMAPHORES];
 	Mutex mutex;
-	SemaphoreOld *sync;
+	Semaphore *sync;
 
 	template <class T>
 	T *allocate() {
diff --git a/core/io/file_access_network.cpp b/core/io/file_access_network.cpp
index 7f1eb6fd90..370dd8f982 100644
--- a/core/io/file_access_network.cpp
+++ b/core/io/file_access_network.cpp
@@ -88,9 +88,7 @@ void FileAccessNetworkClient::_thread_func() {
 	while (!quit) {
 
 		DEBUG_PRINT("SEM WAIT - " + itos(sem->get()));
-		Error err = sem->wait();
-		if (err != OK)
-			ERR_PRINT("sem->wait() failed");
+		sem.wait();
 		DEBUG_TIME("sem_unlock");
 		//DEBUG_PRINT("semwait returned "+itos(werr));
 		DEBUG_PRINT("MUTEX LOCK " + itos(lockcount));
@@ -141,7 +139,7 @@ void FileAccessNetworkClient::_thread_func() {
 					fa->_respond(len, Error(status));
 				}
 
-				fa->sem->post();
+				fa->sem.post();
 
 			} break;
 			case FileAccessNetwork::RESPONSE_DATA: {
@@ -161,14 +159,14 @@ void FileAccessNetworkClient::_thread_func() {
 
 				int status = get_32();
 				fa->exists_modtime = status != 0;
-				fa->sem->post();
+				fa->sem.post();
 
 			} break;
 			case FileAccessNetwork::RESPONSE_GET_MODTIME: {
 
 				uint64_t status = get_64();
 				fa->exists_modtime = status;
-				fa->sem->post();
+				fa->sem.post();
 
 			} break;
 		}
@@ -230,7 +228,6 @@ FileAccessNetworkClient::FileAccessNetworkClient() {
 	singleton = this;
 	last_id = 0;
 	client.instance();
-	sem = SemaphoreOld::create();
 	lockcount = 0;
 }
 
@@ -238,12 +235,10 @@ FileAccessNetworkClient::~FileAccessNetworkClient() {
 
 	if (thread) {
 		quit = true;
-		sem->post();
+		sem.post();
 		Thread::wait_to_finish(thread);
 		memdelete(thread);
 	}
-
-	memdelete(sem);
 }
 
 void FileAccessNetwork::_set_block(int p_offset, const Vector<uint8_t> &p_block) {
@@ -264,7 +259,7 @@ void FileAccessNetwork::_set_block(int p_offset, const Vector<uint8_t> &p_block)
 
 	if (waiting_on_page == page) {
 		waiting_on_page = -1;
-		page_sem->post();
+		page_sem.post();
 	}
 }
 
@@ -306,9 +301,9 @@ Error FileAccessNetwork::_open(const String &p_path, int p_mode_flags) {
 	nc->unlock_mutex();
 	DEBUG_PRINT("OPEN POST");
 	DEBUG_TIME("open_post");
-	nc->sem->post(); //awaiting answer
+	nc->sem.post(); //awaiting answer
 	DEBUG_PRINT("WAIT...");
-	sem->wait();
+	sem.wait();
 	DEBUG_TIME("open_end");
 	DEBUG_PRINT("WAIT ENDED...");
 
@@ -393,7 +388,7 @@ void FileAccessNetwork::_queue_page(int p_page) const {
 			pages.write[p_page].queued = true;
 		}
 		DEBUG_PRINT("QUEUE PAGE POST");
-		nc->sem->post();
+		nc->sem.post();
 		DEBUG_PRINT("queued " + itos(p_page));
 	}
 }
@@ -426,7 +421,7 @@ int FileAccessNetwork::get_buffer(uint8_t *p_dst, int p_length) const {
 				}
 				buffer_mutex.unlock();
 				DEBUG_PRINT("wait");
-				page_sem->wait();
+				page_sem.wait();
 				DEBUG_PRINT("done");
 			} else {
 
@@ -475,8 +470,8 @@ bool FileAccessNetwork::file_exists(const String &p_path) {
 	nc->client->put_data((const uint8_t *)cs.ptr(), cs.length());
 	nc->unlock_mutex();
 	DEBUG_PRINT("FILE EXISTS POST");
-	nc->sem->post();
-	sem->wait();
+	nc->sem.post();
+	sem.wait();
 
 	return exists_modtime != 0;
 }
@@ -492,8 +487,8 @@ uint64_t FileAccessNetwork::_get_modified_time(const String &p_file) {
 	nc->client->put_data((const uint8_t *)cs.ptr(), cs.length());
 	nc->unlock_mutex();
 	DEBUG_PRINT("MODTIME POST");
-	nc->sem->post();
-	sem->wait();
+	nc->sem.post();
+	sem.wait();
 
 	return exists_modtime;
 }
@@ -521,8 +516,6 @@ FileAccessNetwork::FileAccessNetwork() {
 	eof_flag = false;
 	opened = false;
 	pos = 0;
-	sem = SemaphoreOld::create();
-	page_sem = SemaphoreOld::create();
 	FileAccessNetworkClient *nc = FileAccessNetworkClient::singleton;
 	nc->lock_mutex();
 	id = nc->last_id++;
@@ -538,8 +531,6 @@ FileAccessNetwork::FileAccessNetwork() {
 FileAccessNetwork::~FileAccessNetwork() {
 
 	close();
-	memdelete(sem);
-	memdelete(page_sem);
 
 	FileAccessNetworkClient *nc = FileAccessNetworkClient::singleton;
 	nc->lock_mutex();
diff --git a/core/io/file_access_network.h b/core/io/file_access_network.h
index 38d9b8e8a6..7f664b46f7 100644
--- a/core/io/file_access_network.h
+++ b/core/io/file_access_network.h
@@ -49,7 +49,7 @@ class FileAccessNetworkClient {
 
 	List<BlockRequest> block_requests;
 
-	SemaphoreOld *sem;
+	Semaphore sem;
 	Thread *thread;
 	bool quit;
 	Mutex mutex;
@@ -85,8 +85,8 @@ public:
 
 class FileAccessNetwork : public FileAccess {
 
-	SemaphoreOld *sem;
-	SemaphoreOld *page_sem;
+	Semaphore sem;
+	Semaphore page_sem;
 	Mutex buffer_mutex;
 	bool opened;
 	size_t total_size;
diff --git a/core/io/ip.cpp b/core/io/ip.cpp
index af534e4bb7..2143b84d15 100644
--- a/core/io/ip.cpp
+++ b/core/io/ip.cpp
@@ -71,7 +71,7 @@ struct _IP_ResolverPrivate {
 	}
 
 	Mutex mutex;
-	SemaphoreOld *sem;
+	Semaphore sem;
 
 	Thread *thread;
 	//Semaphore* semaphore;
@@ -98,7 +98,7 @@ struct _IP_ResolverPrivate {
 
 		while (!ipr->thread_abort) {
 
-			ipr->sem->wait();
+			ipr->sem.wait();
 
 			MutexLock lock(ipr->mutex);
 			ipr->resolve_queues();
@@ -148,7 +148,7 @@ IP::ResolverID IP::resolve_hostname_queue_item(const String &p_hostname, IP::Typ
 		resolver->queue[id].response = IP_Address();
 		resolver->queue[id].status = IP::RESOLVER_STATUS_WAITING;
 		if (resolver->thread)
-			resolver->sem->post();
+			resolver->sem.post();
 		else
 			resolver->resolve_queues();
 	}
@@ -300,23 +300,13 @@ IP::IP() {
 
 	singleton = this;
 	resolver = memnew(_IP_ResolverPrivate);
-	resolver->sem = NULL;
 
 #ifndef NO_THREADS
 
-	resolver->sem = SemaphoreOld::create();
-	if (resolver->sem) {
-		resolver->thread_abort = false;
+	resolver->thread_abort = false;
 
-		resolver->thread = Thread::create(_IP_ResolverPrivate::_thread_function, resolver);
-
-		if (!resolver->thread)
-			memdelete(resolver->sem); //wtf
-	} else {
-		resolver->thread = NULL;
-	}
+	resolver->thread = Thread::create(_IP_ResolverPrivate::_thread_function, resolver);
 #else
-	resolver->sem = NULL;
 	resolver->thread = NULL;
 #endif
 }
@@ -326,10 +316,9 @@ IP::~IP() {
 #ifndef NO_THREADS
 	if (resolver->thread) {
 		resolver->thread_abort = true;
-		resolver->sem->post();
+		resolver->sem.post();
 		Thread::wait_to_finish(resolver->thread);
 		memdelete(resolver->thread);
-		memdelete(resolver->sem);
 	}
 
 #endif
diff --git a/core/os/mutex.h b/core/os/mutex.h
index 6cf8ee7c40..8d7b378d60 100644
--- a/core/os/mutex.h
+++ b/core/os/mutex.h
@@ -34,7 +34,7 @@
 #include "core/error_list.h"
 #include "core/typedefs.h"
 
-#if !(defined NO_THREADS)
+#if !defined(NO_THREADS)
 
 #include <mutex>
 
diff --git a/core/os/semaphore.cpp b/core/os/semaphore.cpp
index 2c20f234d0..93f1e2dff4 100644
--- a/core/os/semaphore.cpp
+++ b/core/os/semaphore.cpp
@@ -29,17 +29,3 @@
 /*************************************************************************/
 
 #include "semaphore.h"
-
-#include "core/error_macros.h"
-
-SemaphoreOld *(*SemaphoreOld::create_func)() = 0;
-
-SemaphoreOld *SemaphoreOld::create() {
-
-	ERR_FAIL_COND_V(!create_func, 0);
-
-	return create_func();
-}
-
-SemaphoreOld::~SemaphoreOld() {
-}
diff --git a/core/os/semaphore.h b/core/os/semaphore.h
index f16a15a6db..6f194d4887 100644
--- a/core/os/semaphore.h
+++ b/core/os/semaphore.h
@@ -34,30 +34,32 @@
 #include "core/error_list.h"
 #include "core/typedefs.h"
 
+#if !defined(NO_THREADS)
+
 #include <condition_variable>
 #include <mutex>
 
 class Semaphore {
 private:
-	std::mutex mutex_;
-	std::condition_variable condition_;
-	unsigned long count_ = 0; // Initialized as locked.
+	mutable std::mutex mutex_;
+	mutable std::condition_variable condition_;
+	mutable unsigned long count_ = 0; // Initialized as locked.
 
 public:
-	_ALWAYS_INLINE_ void post() {
+	_ALWAYS_INLINE_ void post() const {
 		std::lock_guard<decltype(mutex_)> lock(mutex_);
 		++count_;
 		condition_.notify_one();
 	}
 
-	_ALWAYS_INLINE_ void wait() {
+	_ALWAYS_INLINE_ void wait() const {
 		std::unique_lock<decltype(mutex_)> lock(mutex_);
 		while (!count_) // Handle spurious wake-ups.
 			condition_.wait(lock);
 		--count_;
 	}
 
-	_ALWAYS_INLINE_ bool try_wait() {
+	_ALWAYS_INLINE_ bool try_wait() const {
 		std::lock_guard<decltype(mutex_)> lock(mutex_);
 		if (count_) {
 			--count_;
@@ -67,18 +69,15 @@ public:
 	}
 };
 
-class SemaphoreOld {
-protected:
-	static SemaphoreOld *(*create_func)();
+#else
 
+class Semaphore {
 public:
-	virtual Error wait() = 0; ///< wait until semaphore has positive value, then decrement and pass
-	virtual Error post() = 0; ///< unlock the semaphore, incrementing the    value
-	virtual int get() const = 0; ///< get semaphore value
-
-	static SemaphoreOld *create(); ///< Create a mutex
-
-	virtual ~SemaphoreOld();
+	_ALWAYS_INLINE_ void post() const {}
+	_ALWAYS_INLINE_ void wait() const {}
+	_ALWAYS_INLINE_ bool try_wait() const { return true; }
 };
 
 #endif
+
+#endif
diff --git a/core/os/thread_dummy.cpp b/core/os/thread_dummy.cpp
index 097c90c1fb..9dcddcae11 100644
--- a/core/os/thread_dummy.cpp
+++ b/core/os/thread_dummy.cpp
@@ -40,14 +40,6 @@ void ThreadDummy::make_default() {
 	Thread::create_func = &ThreadDummy::create;
 };
 
-SemaphoreOld *SemaphoreDummy::create() {
-	return memnew(SemaphoreDummy);
-};
-
-void SemaphoreDummy::make_default() {
-	SemaphoreOld::create_func = &SemaphoreDummy::create;
-};
-
 RWLock *RWLockDummy::create() {
 	return memnew(RWLockDummy);
 };
diff --git a/core/os/thread_dummy.h b/core/os/thread_dummy.h
index c0976ec299..da8188f983 100644
--- a/core/os/thread_dummy.h
+++ b/core/os/thread_dummy.h
@@ -45,18 +45,6 @@ public:
 	static void make_default();
 };
 
-class SemaphoreDummy : public SemaphoreOld {
-
-	static SemaphoreOld *create();
-
-public:
-	virtual Error wait() { return OK; };
-	virtual Error post() { return OK; };
-	virtual int get() const { return 0; }; ///< get semaphore value
-
-	static void make_default();
-};
-
 class RWLockDummy : public RWLock {
 
 	static RWLock *create();
diff --git a/doc/classes/Semaphore.xml b/doc/classes/Semaphore.xml
index eca98fb10e..19719eea93 100644
--- a/doc/classes/Semaphore.xml
+++ b/doc/classes/Semaphore.xml
@@ -11,17 +11,24 @@
 	</tutorials>
 	<methods>
 		<method name="post">
-			<return type="int" enum="Error">
+			<return type="void">
 			</return>
 			<description>
-				Lowers the [Semaphore], allowing one more thread in. Returns [constant OK] on success, [constant ERR_BUSY] otherwise.
+				Lowers the [Semaphore], allowing one more thread in.
 			</description>
 		</method>
 		<method name="wait">
+			<return type="void">
+			</return>
+			<description>
+				Waits for the [Semaphore], if its value is zero, blocks until non-zero.
+			</description>
+		</method>
+		<method name="try_wait">
 			<return type="int" enum="Error">
 			</return>
 			<description>
-				Tries to wait for the [Semaphore], if its value is zero, blocks until non-zero. Returns [constant OK] on success, [constant ERR_BUSY] otherwise.
+				Like [method wait], but won't block, so if the value is zero, fails immediately and returns [constant ERR_BUSY]. If non-zero, it returns [constant OK] to report success.
 			</description>
 		</method>
 	</methods>
diff --git a/drivers/unix/os_unix.cpp b/drivers/unix/os_unix.cpp
index 27203b3eed..d21b095037 100644
--- a/drivers/unix/os_unix.cpp
+++ b/drivers/unix/os_unix.cpp
@@ -38,7 +38,6 @@
 #include "drivers/unix/file_access_unix.h"
 #include "drivers/unix/net_socket_posix.h"
 #include "drivers/unix/rw_lock_posix.h"
-#include "drivers/unix/semaphore_posix.h"
 #include "drivers/unix/thread_posix.h"
 #include "servers/visual_server.h"
 
@@ -121,13 +120,9 @@ void OS_Unix::initialize_core() {
 
 #ifdef NO_THREADS
 	ThreadDummy::make_default();
-	SemaphoreDummy::make_default();
 	RWLockDummy::make_default();
 #else
 	ThreadPosix::make_default();
-#if !defined(OSX_ENABLED) && !defined(IPHONE_ENABLED)
-	SemaphorePosix::make_default();
-#endif
 	RWLockPosix::make_default();
 #endif
 	FileAccess::make_default<FileAccessUnix>(FileAccess::ACCESS_RESOURCES);
diff --git a/drivers/unix/semaphore_posix.cpp b/drivers/unix/semaphore_posix.cpp
deleted file mode 100644
index b532b09cd6..0000000000
--- a/drivers/unix/semaphore_posix.cpp
+++ /dev/null
@@ -1,87 +0,0 @@
-/*************************************************************************/
-/*  semaphore_posix.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 "semaphore_posix.h"
-
-#if (defined(UNIX_ENABLED) || defined(PTHREAD_ENABLED)) && !defined(OSX_ENABLED) && !defined(IPHONE_ENABLED)
-
-#include "core/os/memory.h"
-#include <errno.h>
-#include <stdio.h>
-
-Error SemaphorePosix::wait() {
-
-	while (sem_wait(&sem)) {
-		if (errno == EINTR) {
-			errno = 0;
-			continue;
-		} else {
-			perror("sem waiting");
-			return ERR_BUSY;
-		}
-	}
-	return OK;
-}
-
-Error SemaphorePosix::post() {
-
-	return (sem_post(&sem) == 0) ? OK : ERR_BUSY;
-}
-int SemaphorePosix::get() const {
-
-	int val;
-	sem_getvalue(&sem, &val);
-
-	return val;
-}
-
-SemaphoreOld *SemaphorePosix::create_semaphore_posix() {
-
-	return memnew(SemaphorePosix);
-}
-
-void SemaphorePosix::make_default() {
-
-	create_func = create_semaphore_posix;
-}
-
-SemaphorePosix::SemaphorePosix() {
-
-	int r = sem_init(&sem, 0, 0);
-	if (r != 0)
-		perror("sem creating");
-}
-
-SemaphorePosix::~SemaphorePosix() {
-
-	sem_destroy(&sem);
-}
-
-#endif
diff --git a/drivers/unix/semaphore_posix.h b/drivers/unix/semaphore_posix.h
deleted file mode 100644
index 2bffe6933d..0000000000
--- a/drivers/unix/semaphore_posix.h
+++ /dev/null
@@ -1,58 +0,0 @@
-/*************************************************************************/
-/*  semaphore_posix.h                                                    */
-/*************************************************************************/
-/*                       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.                */
-/*************************************************************************/
-
-#ifndef SEMAPHORE_POSIX_H
-#define SEMAPHORE_POSIX_H
-
-#include "core/os/semaphore.h"
-
-#if (defined(UNIX_ENABLED) || defined(PTHREAD_ENABLED)) && !defined(OSX_ENABLED) && !defined(IPHONE_ENABLED)
-
-#include <semaphore.h>
-
-class SemaphorePosix : public SemaphoreOld {
-
-	mutable sem_t sem;
-
-	static SemaphoreOld *create_semaphore_posix();
-
-public:
-	virtual Error wait();
-	virtual Error post();
-	virtual int get() const;
-
-	static void make_default();
-	SemaphorePosix();
-
-	~SemaphorePosix();
-};
-
-#endif
-#endif
diff --git a/drivers/windows/semaphore_windows.cpp b/drivers/windows/semaphore_windows.cpp
deleted file mode 100644
index 1b53e311ff..0000000000
--- a/drivers/windows/semaphore_windows.cpp
+++ /dev/null
@@ -1,98 +0,0 @@
-/*************************************************************************/
-/*  semaphore_windows.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 "semaphore_windows.h"
-
-#if defined(WINDOWS_ENABLED)
-
-#include "core/os/memory.h"
-
-Error SemaphoreWindows::wait() {
-
-	WaitForSingleObjectEx(semaphore, INFINITE, false);
-	return OK;
-}
-Error SemaphoreWindows::post() {
-
-	ReleaseSemaphore(semaphore, 1, NULL);
-	return OK;
-}
-int SemaphoreWindows::get() const {
-	long previous;
-	switch (WaitForSingleObjectEx(semaphore, 0, false)) {
-		case WAIT_OBJECT_0: {
-			ERR_FAIL_COND_V(!ReleaseSemaphore(semaphore, 1, &previous), -1);
-			return previous + 1;
-		} break;
-		case WAIT_TIMEOUT: {
-			return 0;
-		} break;
-		default: {
-		}
-	}
-
-	ERR_FAIL_V(-1);
-}
-
-SemaphoreOld *SemaphoreWindows::create_semaphore_windows() {
-
-	return memnew(SemaphoreWindows);
-}
-
-void SemaphoreWindows::make_default() {
-
-	create_func = create_semaphore_windows;
-}
-
-SemaphoreWindows::SemaphoreWindows() {
-
-#ifdef UWP_ENABLED
-	semaphore = CreateSemaphoreEx(
-			NULL,
-			0,
-			0xFFFFFFF, //wathever
-			NULL,
-			0,
-			SEMAPHORE_ALL_ACCESS);
-#else
-	semaphore = CreateSemaphore(
-			NULL,
-			0,
-			0xFFFFFFF, //wathever
-			NULL);
-#endif
-}
-
-SemaphoreWindows::~SemaphoreWindows() {
-
-	CloseHandle(semaphore);
-}
-
-#endif
diff --git a/drivers/windows/semaphore_windows.h b/drivers/windows/semaphore_windows.h
deleted file mode 100644
index 159e8b3b96..0000000000
--- a/drivers/windows/semaphore_windows.h
+++ /dev/null
@@ -1,58 +0,0 @@
-/*************************************************************************/
-/*  semaphore_windows.h                                                  */
-/*************************************************************************/
-/*                       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.                */
-/*************************************************************************/
-
-#ifndef SEMAPHORE_WINDOWS_H
-#define SEMAPHORE_WINDOWS_H
-
-#include "core/os/semaphore.h"
-
-#ifdef WINDOWS_ENABLED
-
-#include <windows.h>
-
-class SemaphoreWindows : public SemaphoreOld {
-
-	mutable HANDLE semaphore;
-
-	static SemaphoreOld *create_semaphore_windows();
-
-public:
-	virtual Error wait();
-	virtual Error post();
-	virtual int get() const;
-
-	static void make_default();
-	SemaphoreWindows();
-
-	~SemaphoreWindows();
-};
-
-#endif
-#endif
diff --git a/editor/editor_resource_preview.cpp b/editor/editor_resource_preview.cpp
index 40482dc367..3c401a6fc7 100644
--- a/editor/editor_resource_preview.cpp
+++ b/editor/editor_resource_preview.cpp
@@ -217,7 +217,7 @@ void EditorResourcePreview::_thread() {
 	exited = false;
 	while (!exit) {
 
-		preview_sem->wait();
+		preview_sem.wait();
 		preview_mutex.lock();
 
 		if (queue.size()) {
@@ -379,7 +379,7 @@ void EditorResourcePreview::queue_edited_resource_preview(const Ref<Resource> &p
 
 		queue.push_back(item);
 	}
-	preview_sem->post();
+	preview_sem.post();
 }
 
 void EditorResourcePreview::queue_resource_preview(const String &p_path, Object *p_receiver, const StringName &p_receiver_func, const Variant &p_userdata) {
@@ -403,7 +403,7 @@ void EditorResourcePreview::queue_resource_preview(const String &p_path, Object
 
 		queue.push_back(item);
 	}
-	preview_sem->post();
+	preview_sem.post();
 }
 
 void EditorResourcePreview::add_preview_generator(const Ref<EditorResourcePreviewGenerator> &p_generator) {
@@ -462,7 +462,7 @@ void EditorResourcePreview::start() {
 void EditorResourcePreview::stop() {
 	if (thread) {
 		exit = true;
-		preview_sem->post();
+		preview_sem.post();
 		while (!exited) {
 			OS::get_singleton()->delay_usec(10000);
 			VisualServer::get_singleton()->sync(); //sync pending stuff, as thread may be blocked on visual server
@@ -476,7 +476,6 @@ void EditorResourcePreview::stop() {
 EditorResourcePreview::EditorResourcePreview() {
 	thread = NULL;
 	singleton = this;
-	preview_sem = SemaphoreOld::create();
 	order = 0;
 	exit = false;
 	exited = false;
@@ -485,5 +484,4 @@ EditorResourcePreview::EditorResourcePreview() {
 EditorResourcePreview::~EditorResourcePreview() {
 
 	stop();
-	memdelete(preview_sem);
 }
diff --git a/editor/editor_resource_preview.h b/editor/editor_resource_preview.h
index ae347c0469..0e1684963c 100644
--- a/editor/editor_resource_preview.h
+++ b/editor/editor_resource_preview.h
@@ -71,7 +71,7 @@ class EditorResourcePreview : public Node {
 	List<QueueItem> queue;
 
 	Mutex preview_mutex;
-	SemaphoreOld *preview_sem;
+	Semaphore preview_sem;
 	Thread *thread;
 	volatile bool exit;
 	volatile bool exited;
diff --git a/platform/iphone/os_iphone.cpp b/platform/iphone/os_iphone.cpp
index 8a50f5a28b..497f2f747d 100644
--- a/platform/iphone/os_iphone.cpp
+++ b/platform/iphone/os_iphone.cpp
@@ -100,7 +100,6 @@ String OSIPhone::get_unique_id() const {
 void OSIPhone::initialize_core() {
 
 	OS_Unix::initialize_core();
-	SemaphoreIphone::make_default();
 
 	set_data_dir(data_dir);
 };
diff --git a/platform/iphone/semaphore_iphone.cpp b/platform/iphone/semaphore_iphone.cpp
deleted file mode 100644
index 0461f58c40..0000000000
--- a/platform/iphone/semaphore_iphone.cpp
+++ /dev/null
@@ -1,112 +0,0 @@
-/*************************************************************************/
-/*  semaphore_iphone.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 "semaphore_iphone.h"
-
-#include <fcntl.h>
-#include <unistd.h>
-
-void cgsem_init(cgsem_t *);
-void cgsem_post(cgsem_t *);
-void cgsem_wait(cgsem_t *);
-void cgsem_destroy(cgsem_t *);
-
-void cgsem_init(cgsem_t *cgsem) {
-	int flags, fd, i;
-
-	pipe(cgsem->pipefd);
-
-	/* Make the pipes FD_CLOEXEC to allow them to close should we call
-	 * execv on restart. */
-	for (i = 0; i < 2; i++) {
-		fd = cgsem->pipefd[i];
-		flags = fcntl(fd, F_GETFD, 0);
-		flags |= FD_CLOEXEC;
-		fcntl(fd, F_SETFD, flags);
-	}
-}
-
-void cgsem_post(cgsem_t *cgsem) {
-	const char buf = 1;
-
-	write(cgsem->pipefd[1], &buf, 1);
-}
-
-void cgsem_wait(cgsem_t *cgsem) {
-	char buf;
-
-	read(cgsem->pipefd[0], &buf, 1);
-}
-
-void cgsem_destroy(cgsem_t *cgsem) {
-	close(cgsem->pipefd[1]);
-	close(cgsem->pipefd[0]);
-}
-
-#include "core/os/memory.h"
-
-#include <errno.h>
-
-Error SemaphoreIphone::wait() {
-
-	cgsem_wait(&sem);
-	return OK;
-}
-
-Error SemaphoreIphone::post() {
-
-	cgsem_post(&sem);
-
-	return OK;
-}
-int SemaphoreIphone::get() const {
-
-	return 0;
-}
-
-SemaphoreOld *SemaphoreIphone::create_semaphore_iphone() {
-
-	return memnew(SemaphoreIphone);
-}
-
-void SemaphoreIphone::make_default() {
-
-	create_func = create_semaphore_iphone;
-}
-
-SemaphoreIphone::SemaphoreIphone() {
-
-	cgsem_init(&sem);
-}
-
-SemaphoreIphone::~SemaphoreIphone() {
-
-	cgsem_destroy(&sem);
-}
diff --git a/platform/iphone/semaphore_iphone.h b/platform/iphone/semaphore_iphone.h
deleted file mode 100644
index 54ff3c17f9..0000000000
--- a/platform/iphone/semaphore_iphone.h
+++ /dev/null
@@ -1,59 +0,0 @@
-/*************************************************************************/
-/*  semaphore_iphone.h                                                   */
-/*************************************************************************/
-/*                       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.                */
-/*************************************************************************/
-
-#ifndef SEMAPHORE_IPHONE_H
-#define SEMAPHORE_IPHONE_H
-
-struct cgsem {
-	int pipefd[2];
-};
-
-typedef struct cgsem cgsem_t;
-
-#include "core/os/semaphore.h"
-
-class SemaphoreIphone : public SemaphoreOld {
-
-	mutable cgsem_t sem;
-
-	static SemaphoreOld *create_semaphore_iphone();
-
-public:
-	virtual Error wait();
-	virtual Error post();
-	virtual int get() const;
-
-	static void make_default();
-	SemaphoreIphone();
-
-	~SemaphoreIphone();
-};
-
-#endif // SEMAPHORE_IPHONE_H
diff --git a/platform/osx/SCsub b/platform/osx/SCsub
index d764ac4b50..0a4e0a45e1 100644
--- a/platform/osx/SCsub
+++ b/platform/osx/SCsub
@@ -9,7 +9,6 @@ files = [
     'crash_handler_osx.mm',
     'os_osx.mm',
     'godot_main_osx.mm',
-    'semaphore_osx.cpp',
     'dir_access_osx.mm',
     'joypad_osx.cpp',
     'vulkan_context_osx.mm',
diff --git a/platform/osx/os_osx.mm b/platform/osx/os_osx.mm
index 952360c6aa..4c70beee00 100644
--- a/platform/osx/os_osx.mm
+++ b/platform/osx/os_osx.mm
@@ -44,7 +44,6 @@
 #endif
 
 #include "main/main.h"
-#include "semaphore_osx.h"
 #include "servers/visual/visual_server_raster.h"
 #include "servers/visual/visual_server_wrap_mt.h"
 
@@ -1464,8 +1463,6 @@ void OS_OSX::initialize_core() {
 	DirAccess::make_default<DirAccessOSX>(DirAccess::ACCESS_RESOURCES);
 	DirAccess::make_default<DirAccessOSX>(DirAccess::ACCESS_USERDATA);
 	DirAccess::make_default<DirAccessOSX>(DirAccess::ACCESS_FILESYSTEM);
-
-	SemaphoreOSX::make_default();
 }
 
 static bool keyboard_layout_dirty = true;
diff --git a/platform/osx/semaphore_osx.cpp b/platform/osx/semaphore_osx.cpp
deleted file mode 100644
index e4e5991637..0000000000
--- a/platform/osx/semaphore_osx.cpp
+++ /dev/null
@@ -1,107 +0,0 @@
-/*************************************************************************/
-/*  semaphore_osx.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 "semaphore_osx.h"
-
-#include <fcntl.h>
-#include <unistd.h>
-
-void cgsem_init(cgsem_t *cgsem) {
-	int flags, fd, i;
-
-	pipe(cgsem->pipefd);
-
-	/* Make the pipes FD_CLOEXEC to allow them to close should we call
-	 * execv on restart. */
-	for (i = 0; i < 2; i++) {
-		fd = cgsem->pipefd[i];
-		flags = fcntl(fd, F_GETFD, 0);
-		flags |= FD_CLOEXEC;
-		fcntl(fd, F_SETFD, flags);
-	}
-}
-
-void cgsem_post(cgsem_t *cgsem) {
-	const char buf = 1;
-
-	write(cgsem->pipefd[1], &buf, 1);
-}
-
-void cgsem_wait(cgsem_t *cgsem) {
-	char buf;
-
-	read(cgsem->pipefd[0], &buf, 1);
-}
-
-void cgsem_destroy(cgsem_t *cgsem) {
-	close(cgsem->pipefd[1]);
-	close(cgsem->pipefd[0]);
-}
-
-#include "core/os/memory.h"
-
-#include <errno.h>
-
-Error SemaphoreOSX::wait() {
-
-	cgsem_wait(&sem);
-	return OK;
-}
-
-Error SemaphoreOSX::post() {
-
-	cgsem_post(&sem);
-
-	return OK;
-}
-int SemaphoreOSX::get() const {
-
-	return 0;
-}
-
-SemaphoreOld *SemaphoreOSX::create_semaphore_osx() {
-
-	return memnew(SemaphoreOSX);
-}
-
-void SemaphoreOSX::make_default() {
-
-	create_func = create_semaphore_osx;
-}
-
-SemaphoreOSX::SemaphoreOSX() {
-
-	cgsem_init(&sem);
-}
-
-SemaphoreOSX::~SemaphoreOSX() {
-
-	cgsem_destroy(&sem);
-}
diff --git a/platform/osx/semaphore_osx.h b/platform/osx/semaphore_osx.h
deleted file mode 100644
index 9aa2b47bc8..0000000000
--- a/platform/osx/semaphore_osx.h
+++ /dev/null
@@ -1,59 +0,0 @@
-/*************************************************************************/
-/*  semaphore_osx.h                                                      */
-/*************************************************************************/
-/*                       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.                */
-/*************************************************************************/
-
-#ifndef SEMAPHORE_OSX_H
-#define SEMAPHORE_OSX_H
-
-struct cgsem {
-	int pipefd[2];
-};
-
-typedef struct cgsem cgsem_t;
-
-#include "core/os/semaphore.h"
-
-class SemaphoreOSX : public SemaphoreOld {
-
-	mutable cgsem_t sem;
-
-	static SemaphoreOld *create_semaphore_osx();
-
-public:
-	virtual Error wait();
-	virtual Error post();
-	virtual int get() const;
-
-	static void make_default();
-	SemaphoreOSX();
-
-	~SemaphoreOSX();
-};
-
-#endif // SEMAPHORE_OSX_H
diff --git a/platform/server/SCsub b/platform/server/SCsub
index e8538f03a6..8364164114 100644
--- a/platform/server/SCsub
+++ b/platform/server/SCsub
@@ -10,7 +10,6 @@ common_server = [\
 
 if sys.platform == "darwin":
 	common_server.append("#platform/osx/crash_handler_osx.mm")
-	common_server.append("#platform/osx/semaphore_osx.cpp")
 else:
 	common_server.append("#platform/x11/crash_handler_x11.cpp")
 
diff --git a/platform/server/os_server.cpp b/platform/server/os_server.cpp
index 8a66332ff1..3257ec261c 100644
--- a/platform/server/os_server.cpp
+++ b/platform/server/os_server.cpp
@@ -68,10 +68,6 @@ void OS_Server::initialize_core() {
 	crash_handler.initialize();
 
 	OS_Unix::initialize_core();
-
-#ifdef __APPLE__
-	SemaphoreOSX::make_default();
-#endif
 }
 
 Error OS_Server::initialize(const VideoMode &p_desired, int p_video_driver, int p_audio_driver) {
diff --git a/platform/uwp/os_uwp.cpp b/platform/uwp/os_uwp.cpp
index 97c8dafe65..4ddb5463d0 100644
--- a/platform/uwp/os_uwp.cpp
+++ b/platform/uwp/os_uwp.cpp
@@ -140,7 +140,6 @@ void OS_UWP::initialize_core() {
 	//RedirectIOToConsole();
 
 	ThreadUWP::make_default();
-	SemaphoreWindows::make_default();
 	RWLockWindows::make_default();
 
 	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_RESOURCES);
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index 6757f60a06..63f0cd53a4 100644
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -48,7 +48,6 @@
 #include "drivers/windows/dir_access_windows.h"
 #include "drivers/windows/file_access_windows.h"
 #include "drivers/windows/rw_lock_windows.h"
-#include "drivers/windows/semaphore_windows.h"
 #include "drivers/windows/thread_windows.h"
 #include "joypad_windows.h"
 #include "lang_table.h"
@@ -228,7 +227,6 @@ void OS_Windows::initialize_core() {
 	borderless = false;
 
 	ThreadWindows::make_default();
-	SemaphoreWindows::make_default();
 	RWLockWindows::make_default();
 
 	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_RESOURCES);
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();