diff --git a/core/class_db.cpp b/core/class_db.cpp
index 08c4d4b80b4..12ca85991fd 100644
--- a/core/class_db.cpp
+++ b/core/class_db.cpp
@@ -929,9 +929,9 @@ void ClassDB::add_property_group(StringName p_class, const String &p_name, const
 
 void ClassDB::add_property(StringName p_class, const PropertyInfo &p_pinfo, const StringName &p_setter, const StringName &p_getter, int p_index) {
 
-	lock->read_lock();
+	lock.read_lock();
 	ClassInfo *type = classes.getptr(p_class);
-	lock->read_unlock();
+	lock.read_unlock();
 
 	ERR_FAIL_COND(!type);
 
@@ -1447,12 +1447,7 @@ Variant ClassDB::class_get_default_property_value(const StringName &p_class, con
 	return default_values[p_class][p_property];
 }
 
-RWLock *ClassDB::lock = NULL;
-
-void ClassDB::init() {
-
-	lock = RWLock::create();
-}
+RWLock ClassDB::lock;
 
 void ClassDB::cleanup_defaults() {
 
@@ -1479,8 +1474,6 @@ void ClassDB::cleanup() {
 	classes.clear();
 	resource_base_extensions.clear();
 	compat_classes.clear();
-
-	memdelete(lock);
 }
 
 //
diff --git a/core/class_db.h b/core/class_db.h
index 0fed9110bbd..136af723765 100644
--- a/core/class_db.h
+++ b/core/class_db.h
@@ -143,7 +143,7 @@ public:
 		return memnew(T);
 	}
 
-	static RWLock *lock;
+	static RWLock lock;
 	static HashMap<StringName, ClassInfo> classes;
 	static HashMap<StringName, StringName> resource_base_extensions;
 	static HashMap<StringName, StringName> compat_classes;
@@ -393,7 +393,6 @@ public:
 	static void get_extensions_for_type(const StringName &p_class, List<String> *p_extensions);
 
 	static void add_compatibility_class(const StringName &p_class, const StringName &p_fallback);
-	static void init();
 
 	static void set_current_api(APIType p_api);
 	static APIType get_current_api();
diff --git a/core/io/resource_loader.cpp b/core/io/resource_loader.cpp
index e65a4fdc6fe..0697f291216 100644
--- a/core/io/resource_loader.cpp
+++ b/core/io/resource_loader.cpp
@@ -362,9 +362,7 @@ RES ResourceLoader::load(const String &p_path, const String &p_type_hint, bool p
 		}
 
 		//lock first if possible
-		if (ResourceCache::lock) {
-			ResourceCache::lock->read_lock();
-		}
+		ResourceCache::lock.read_lock();
 
 		//get ptr
 		Resource **rptr = ResourceCache::resources.getptr(local_path);
@@ -376,16 +374,12 @@ RES ResourceLoader::load(const String &p_path, const String &p_type_hint, bool p
 				//referencing is fine
 				if (r_error)
 					*r_error = OK;
-				if (ResourceCache::lock) {
-					ResourceCache::lock->read_unlock();
-				}
+				ResourceCache::lock.read_unlock();
 				_remove_from_loading_map(local_path);
 				return res;
 			}
 		}
-		if (ResourceCache::lock) {
-			ResourceCache::lock->read_unlock();
-		}
+		ResourceCache::lock.read_unlock();
 	}
 
 	bool xl_remapped = false;
@@ -851,9 +845,7 @@ String ResourceLoader::path_remap(const String &p_path) {
 
 void ResourceLoader::reload_translation_remaps() {
 
-	if (ResourceCache::lock) {
-		ResourceCache::lock->read_lock();
-	}
+	ResourceCache::lock.read_lock();
 
 	List<Resource *> to_reload;
 	SelfList<Resource> *E = remapped_list.first();
@@ -863,9 +855,7 @@ void ResourceLoader::reload_translation_remaps() {
 		E = E->next();
 	}
 
-	if (ResourceCache::lock) {
-		ResourceCache::lock->read_unlock();
-	}
+	ResourceCache::lock.read_unlock();
 
 	//now just make sure to not delete any of these resources while changing locale..
 	while (to_reload.front()) {
diff --git a/core/object.cpp b/core/object.cpp
index 3604ca8843d..5a7f759806a 100644
--- a/core/object.cpp
+++ b/core/object.cpp
@@ -2068,30 +2068,30 @@ ObjectID ObjectDB::add_instance(Object *p_object) {
 
 	ERR_FAIL_COND_V(p_object->get_instance_id() != 0, 0);
 
-	rw_lock->write_lock();
+	rw_lock.write_lock();
 	ObjectID instance_id = ++instance_counter;
 	instances[instance_id] = p_object;
 	instance_checks[p_object] = instance_id;
 
-	rw_lock->write_unlock();
+	rw_lock.write_unlock();
 
 	return instance_id;
 }
 
 void ObjectDB::remove_instance(Object *p_object) {
 
-	rw_lock->write_lock();
+	rw_lock.write_lock();
 
 	instances.erase(p_object->get_instance_id());
 	instance_checks.erase(p_object);
 
-	rw_lock->write_unlock();
+	rw_lock.write_unlock();
 }
 Object *ObjectDB::get_instance(ObjectID p_instance_id) {
 
-	rw_lock->read_lock();
+	rw_lock.read_lock();
 	Object **obj = instances.getptr(p_instance_id);
-	rw_lock->read_unlock();
+	rw_lock.read_unlock();
 
 	if (!obj)
 		return NULL;
@@ -2100,7 +2100,7 @@ Object *ObjectDB::get_instance(ObjectID p_instance_id) {
 
 void ObjectDB::debug_objects(DebugFunc p_func) {
 
-	rw_lock->read_lock();
+	rw_lock.read_lock();
 
 	const ObjectID *K = NULL;
 	while ((K = instances.next(K))) {
@@ -2108,7 +2108,7 @@ void ObjectDB::debug_objects(DebugFunc p_func) {
 		p_func(instances[*K]);
 	}
 
-	rw_lock->read_unlock();
+	rw_lock.read_unlock();
 }
 
 void Object::get_argument_options(const StringName &p_function, int p_idx, List<String> *r_options) const {
@@ -2116,23 +2116,18 @@ void Object::get_argument_options(const StringName &p_function, int p_idx, List<
 
 int ObjectDB::get_object_count() {
 
-	rw_lock->read_lock();
+	rw_lock.read_lock();
 	int count = instances.size();
-	rw_lock->read_unlock();
+	rw_lock.read_unlock();
 
 	return count;
 }
 
-RWLock *ObjectDB::rw_lock = NULL;
-
-void ObjectDB::setup() {
-
-	rw_lock = RWLock::create();
-}
+RWLock ObjectDB::rw_lock;
 
 void ObjectDB::cleanup() {
 
-	rw_lock->write_lock();
+	rw_lock.write_lock();
 	if (instances.size()) {
 
 		WARN_PRINT("ObjectDB instances leaked at exit (run with --verbose for details).");
@@ -2159,6 +2154,5 @@ void ObjectDB::cleanup() {
 	}
 	instances.clear();
 	instance_checks.clear();
-	rw_lock->write_unlock();
-	memdelete(rw_lock);
+	rw_lock.write_unlock();
 }
diff --git a/core/object.h b/core/object.h
index b0d1e9505b8..50e8468b2d3 100644
--- a/core/object.h
+++ b/core/object.h
@@ -791,12 +791,11 @@ class ObjectDB {
 	friend class Object;
 	friend void unregister_core_types();
 
-	static RWLock *rw_lock;
+	static RWLock rw_lock;
 	static void cleanup();
 	static ObjectID add_instance(Object *p_object);
 	static void remove_instance(Object *p_object);
 	friend void register_core_types();
-	static void setup();
 
 public:
 	typedef void (*DebugFunc)(Object *p_obj);
@@ -806,11 +805,11 @@ public:
 	static int get_object_count();
 
 	_FORCE_INLINE_ static bool instance_validate(Object *p_ptr) {
-		rw_lock->read_lock();
+		rw_lock.read_lock();
 
 		bool exists = instance_checks.has(p_ptr);
 
-		rw_lock->read_unlock();
+		rw_lock.read_unlock();
 
 		return exists;
 	}
diff --git a/core/os/rw_lock.cpp b/core/os/rw_lock.cpp
deleted file mode 100644
index 681845efe47..00000000000
--- a/core/os/rw_lock.cpp
+++ /dev/null
@@ -1,47 +0,0 @@
-/*************************************************************************/
-/*  rw_lock.cpp                                                          */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                      https://godotengine.org                          */
-/*************************************************************************/
-/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2021 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 "rw_lock.h"
-
-#include "core/error_macros.h"
-
-#include <stddef.h>
-
-RWLock *(*RWLock::create_func)() = 0;
-
-RWLock *RWLock::create() {
-
-	ERR_FAIL_COND_V(!create_func, 0);
-
-	return create_func();
-}
-
-RWLock::~RWLock() {
-}
diff --git a/core/os/rw_lock.h b/core/os/rw_lock.h
index 6fecc1fed86..2e61ddd685e 100644
--- a/core/os/rw_lock.h
+++ b/core/os/rw_lock.h
@@ -33,49 +33,85 @@
 
 #include "core/error_list.h"
 
+#if !defined(NO_THREADS)
+
+#include <shared_mutex>
+
 class RWLock {
-protected:
-	static RWLock *(*create_func)();
+	mutable std::shared_timed_mutex mutex;
 
 public:
-	virtual void read_lock() = 0; ///< Lock the rwlock, block if locked by someone else
-	virtual void read_unlock() = 0; ///< Unlock the rwlock, let other threads continue
-	virtual Error read_try_lock() = 0; ///< Attempt to lock the rwlock, OK on success, ERROR means it can't lock.
+	// Lock the rwlock, block if locked by someone else
+	void read_lock() const {
+		mutex.lock_shared();
+	}
 
-	virtual void write_lock() = 0; ///< Lock the rwlock, block if locked by someone else
-	virtual void write_unlock() = 0; ///< Unlock the rwlock, let other thwrites continue
-	virtual Error write_try_lock() = 0; ///< Attempt to lock the rwlock, OK on success, ERROR means it can't lock.
+	// Unlock the rwlock, let other threads continue
+	void read_unlock() const {
+		mutex.unlock_shared();
+	}
 
-	static RWLock *create(); ///< Create a rwlock
+	// Attempt to lock the rwlock, OK on success, ERR_BUSY means it can't lock.
+	Error read_try_lock() const {
+		return mutex.try_lock_shared() ? OK : ERR_BUSY;
+	}
 
-	virtual ~RWLock();
+	// Lock the rwlock, block if locked by someone else
+	void write_lock() {
+		mutex.lock();
+	}
+
+	// Unlock the rwlock, let other thwrites continue
+	void write_unlock() {
+		mutex.unlock();
+	}
+
+	// Attempt to lock the rwlock, OK on success, ERR_BUSY means it can't lock.
+	Error write_try_lock() {
+		return mutex.try_lock() ? OK : ERR_BUSY;
+	}
 };
 
+#else
+
+class RWLock {
+public:
+	void read_lock() const {}
+	void read_unlock() const {}
+	Error read_try_lock() const { return OK; }
+
+	void write_lock() {}
+	void write_unlock() {}
+	Error write_try_lock() { return OK; }
+};
+
+#endif
+
 class RWLockRead {
 
-	RWLock *lock;
+	const RWLock &lock;
 
 public:
-	RWLockRead(const RWLock *p_lock) {
-		lock = const_cast<RWLock *>(p_lock);
-		if (lock) lock->read_lock();
+	RWLockRead(const RWLock &p_lock) :
+			lock(p_lock) {
+		lock.read_lock();
 	}
 	~RWLockRead() {
-		if (lock) lock->read_unlock();
+		lock.read_unlock();
 	}
 };
 
 class RWLockWrite {
 
-	RWLock *lock;
+	RWLock &lock;
 
 public:
-	RWLockWrite(RWLock *p_lock) {
-		lock = p_lock;
-		if (lock) lock->write_lock();
+	RWLockWrite(RWLock &p_lock) :
+			lock(p_lock) {
+		lock.write_lock();
 	}
 	~RWLockWrite() {
-		if (lock) lock->write_unlock();
+		lock.write_unlock();
 	}
 };
 
diff --git a/core/os/thread_dummy.cpp b/core/os/thread_dummy.cpp
index 0e6a59a11ac..e9298ccb37c 100644
--- a/core/os/thread_dummy.cpp
+++ b/core/os/thread_dummy.cpp
@@ -55,11 +55,3 @@ Semaphore *SemaphoreDummy::create() {
 void SemaphoreDummy::make_default() {
 	Semaphore::create_func = &SemaphoreDummy::create;
 };
-
-RWLock *RWLockDummy::create() {
-	return memnew(RWLockDummy);
-};
-
-void RWLockDummy::make_default() {
-	RWLock::create_func = &RWLockDummy::create;
-};
diff --git a/core/os/thread_dummy.h b/core/os/thread_dummy.h
index 6f3837a9116..594b3c05454 100644
--- a/core/os/thread_dummy.h
+++ b/core/os/thread_dummy.h
@@ -32,7 +32,6 @@
 #define THREAD_DUMMY_H
 
 #include "core/os/mutex.h"
-#include "core/os/rw_lock.h"
 #include "core/os/semaphore.h"
 #include "core/os/thread.h"
 
@@ -70,20 +69,4 @@ public:
 	static void make_default();
 };
 
-class RWLockDummy : public RWLock {
-
-	static RWLock *create();
-
-public:
-	virtual void read_lock() {}
-	virtual void read_unlock() {}
-	virtual Error read_try_lock() { return OK; }
-
-	virtual void write_lock() {}
-	virtual void write_unlock() {}
-	virtual Error write_try_lock() { return OK; }
-
-	static void make_default();
-};
-
 #endif
diff --git a/core/register_core_types.cpp b/core/register_core_types.cpp
index b1cdab53085..b973ac85d1d 100644
--- a/core/register_core_types.cpp
+++ b/core/register_core_types.cpp
@@ -99,8 +99,6 @@ extern void unregister_variant_methods();
 
 void register_core_types() {
 
-	ObjectDB::setup();
-	ResourceCache::setup();
 	MemoryPool::setup();
 
 	_global_mutex = Mutex::create();
diff --git a/core/resource.cpp b/core/resource.cpp
index 0ba5ee3734e..f0c30928dc5 100644
--- a/core/resource.cpp
+++ b/core/resource.cpp
@@ -54,30 +54,30 @@ void Resource::set_path(const String &p_path, bool p_take_over) {
 
 	if (path_cache != "") {
 
-		ResourceCache::lock->write_lock();
+		ResourceCache::lock.write_lock();
 		ResourceCache::resources.erase(path_cache);
-		ResourceCache::lock->write_unlock();
+		ResourceCache::lock.write_unlock();
 	}
 
 	path_cache = "";
 
-	ResourceCache::lock->read_lock();
+	ResourceCache::lock.read_lock();
 	bool has_path = ResourceCache::resources.has(p_path);
-	ResourceCache::lock->read_unlock();
+	ResourceCache::lock.read_unlock();
 
 	if (has_path) {
 		if (p_take_over) {
 
-			ResourceCache::lock->write_lock();
+			ResourceCache::lock.write_lock();
 			Resource **res = ResourceCache::resources.getptr(p_path);
 			if (res) {
 				(*res)->set_name("");
 			}
-			ResourceCache::lock->write_unlock();
+			ResourceCache::lock.write_unlock();
 		} else {
-			ResourceCache::lock->read_lock();
+			ResourceCache::lock.read_lock();
 			bool exists = ResourceCache::resources.has(p_path);
-			ResourceCache::lock->read_unlock();
+			ResourceCache::lock.read_unlock();
 
 			ERR_FAIL_COND_MSG(exists, "Another resource is loaded from path '" + p_path + "' (possible cyclic resource inclusion).");
 		}
@@ -86,9 +86,9 @@ void Resource::set_path(const String &p_path, bool p_take_over) {
 
 	if (path_cache != "") {
 
-		ResourceCache::lock->write_lock();
+		ResourceCache::lock.write_lock();
 		ResourceCache::resources[path_cache] = this;
-		ResourceCache::lock->write_unlock();
+		ResourceCache::lock.write_unlock();
 	}
 
 	_change_notify("resource_path");
@@ -343,9 +343,7 @@ void Resource::set_as_translation_remapped(bool p_remapped) {
 	if (remapped_list.in_list() == p_remapped)
 		return;
 
-	if (ResourceCache::lock) {
-		ResourceCache::lock->write_lock();
-	}
+	ResourceCache::lock.write_lock();
 
 	if (p_remapped) {
 		ResourceLoader::remapped_list.add(&remapped_list);
@@ -353,9 +351,7 @@ void Resource::set_as_translation_remapped(bool p_remapped) {
 		ResourceLoader::remapped_list.remove(&remapped_list);
 	}
 
-	if (ResourceCache::lock) {
-		ResourceCache::lock->write_unlock();
-	}
+	ResourceCache::lock.write_unlock();
 }
 
 bool Resource::is_translation_remapped() const {
@@ -367,38 +363,24 @@ bool Resource::is_translation_remapped() const {
 //helps keep IDs same number when loading/saving scenes. -1 clears ID and it Returns -1 when no id stored
 void Resource::set_id_for_path(const String &p_path, int p_id) {
 	if (p_id == -1) {
-		if (ResourceCache::path_cache_lock) {
-			ResourceCache::path_cache_lock->write_lock();
-		}
+		ResourceCache::path_cache_lock.write_lock();
 		ResourceCache::resource_path_cache[p_path].erase(get_path());
-		if (ResourceCache::path_cache_lock) {
-			ResourceCache::path_cache_lock->write_unlock();
-		}
+		ResourceCache::path_cache_lock.write_unlock();
 	} else {
-		if (ResourceCache::path_cache_lock) {
-			ResourceCache::path_cache_lock->write_lock();
-		}
+		ResourceCache::path_cache_lock.write_lock();
 		ResourceCache::resource_path_cache[p_path][get_path()] = p_id;
-		if (ResourceCache::path_cache_lock) {
-			ResourceCache::path_cache_lock->write_unlock();
-		}
+		ResourceCache::path_cache_lock.write_unlock();
 	}
 }
 
 int Resource::get_id_for_path(const String &p_path) const {
-	if (ResourceCache::path_cache_lock) {
-		ResourceCache::path_cache_lock->read_lock();
-	}
+	ResourceCache::path_cache_lock.read_lock();
 	if (ResourceCache::resource_path_cache[p_path].has(get_path())) {
 		int result = ResourceCache::resource_path_cache[p_path][get_path()];
-		if (ResourceCache::path_cache_lock) {
-			ResourceCache::path_cache_lock->read_unlock();
-		}
+		ResourceCache::path_cache_lock.read_unlock();
 		return result;
 	} else {
-		if (ResourceCache::path_cache_lock) {
-			ResourceCache::path_cache_lock->read_unlock();
-		}
+		ResourceCache::path_cache_lock.read_unlock();
 		return -1;
 	}
 }
@@ -444,9 +426,9 @@ Resource::Resource() :
 Resource::~Resource() {
 
 	if (path_cache != "") {
-		ResourceCache::lock->write_lock();
+		ResourceCache::lock.write_lock();
 		ResourceCache::resources.erase(path_cache);
-		ResourceCache::lock->write_unlock();
+		ResourceCache::lock.write_unlock();
 	}
 	if (owners.size()) {
 		WARN_PRINT("Resource is still owned.");
@@ -458,19 +440,11 @@ HashMap<String, Resource *> ResourceCache::resources;
 HashMap<String, HashMap<String, int> > ResourceCache::resource_path_cache;
 #endif
 
-RWLock *ResourceCache::lock = NULL;
+RWLock ResourceCache::lock;
 #ifdef TOOLS_ENABLED
-RWLock *ResourceCache::path_cache_lock = NULL;
+RWLock ResourceCache::path_cache_lock;
 #endif
 
-void ResourceCache::setup() {
-
-	lock = RWLock::create();
-#ifdef TOOLS_ENABLED
-	path_cache_lock = RWLock::create();
-#endif
-}
-
 void ResourceCache::clear() {
 	if (resources.size()) {
 		ERR_PRINT("Resources still in use at exit (run with --verbose for details).");
@@ -484,7 +458,6 @@ void ResourceCache::clear() {
 	}
 
 	resources.clear();
-	memdelete(lock);
 }
 
 void ResourceCache::reload_externals() {
@@ -492,19 +465,19 @@ void ResourceCache::reload_externals() {
 
 bool ResourceCache::has(const String &p_path) {
 
-	lock->read_lock();
+	lock.read_lock();
 	bool b = resources.has(p_path);
-	lock->read_unlock();
+	lock.read_unlock();
 
 	return b;
 }
 Resource *ResourceCache::get(const String &p_path) {
 
-	lock->read_lock();
+	lock.read_lock();
 
 	Resource **res = resources.getptr(p_path);
 
-	lock->read_unlock();
+	lock.read_unlock();
 
 	if (!res) {
 		return NULL;
@@ -515,28 +488,28 @@ Resource *ResourceCache::get(const String &p_path) {
 
 void ResourceCache::get_cached_resources(List<Ref<Resource> > *p_resources) {
 
-	lock->read_lock();
+	lock.read_lock();
 	const String *K = NULL;
 	while ((K = resources.next(K))) {
 
 		Resource *r = resources[*K];
 		p_resources->push_back(Ref<Resource>(r));
 	}
-	lock->read_unlock();
+	lock.read_unlock();
 }
 
 int ResourceCache::get_cached_resource_count() {
 
-	lock->read_lock();
+	lock.read_lock();
 	int rc = resources.size();
-	lock->read_unlock();
+	lock.read_unlock();
 
 	return rc;
 }
 
 void ResourceCache::dump(const char *p_file, bool p_short) {
 #ifdef DEBUG_ENABLED
-	lock->read_lock();
+	lock.read_lock();
 
 	Map<String, int> type_count;
 
@@ -573,6 +546,6 @@ void ResourceCache::dump(const char *p_file, bool p_short) {
 		memdelete(f);
 	}
 
-	lock->read_unlock();
+	lock.read_unlock();
 #endif
 }
diff --git a/core/resource.h b/core/resource.h
index 74b6a00e11e..d94e1b54314 100644
--- a/core/resource.h
+++ b/core/resource.h
@@ -148,16 +148,15 @@ typedef Ref<Resource> RES;
 class ResourceCache {
 	friend class Resource;
 	friend class ResourceLoader; //need the lock
-	static RWLock *lock;
+	static RWLock lock;
 	static HashMap<String, Resource *> resources;
 #ifdef TOOLS_ENABLED
 	static HashMap<String, HashMap<String, int> > resource_path_cache; // each tscn has a set of resource paths and IDs
-	static RWLock *path_cache_lock;
+	static RWLock path_cache_lock;
 #endif // TOOLS_ENABLED
 	friend void unregister_core_types();
 	static void clear();
 	friend void register_core_types();
-	static void setup();
 
 public:
 	static void reload_externals();
diff --git a/drivers/unix/os_unix.cpp b/drivers/unix/os_unix.cpp
index 4bb56ab931c..9fd8c2d855a 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/mutex_posix.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"
@@ -124,14 +123,12 @@ void OS_Unix::initialize_core() {
 	ThreadDummy::make_default();
 	SemaphoreDummy::make_default();
 	MutexDummy::make_default();
-	RWLockDummy::make_default();
 #else
 	ThreadPosix::make_default();
 #if !defined(OSX_ENABLED) && !defined(IPHONE_ENABLED)
 	SemaphorePosix::make_default();
 #endif
 	MutexPosix::make_default();
-	RWLockPosix::make_default();
 #endif
 	FileAccess::make_default<FileAccessUnix>(FileAccess::ACCESS_RESOURCES);
 	FileAccess::make_default<FileAccessUnix>(FileAccess::ACCESS_USERDATA);
diff --git a/drivers/unix/rw_lock_posix.cpp b/drivers/unix/rw_lock_posix.cpp
deleted file mode 100644
index 58cefabe3a9..00000000000
--- a/drivers/unix/rw_lock_posix.cpp
+++ /dev/null
@@ -1,102 +0,0 @@
-/*************************************************************************/
-/*  rw_lock_posix.cpp                                                    */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                      https://godotengine.org                          */
-/*************************************************************************/
-/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2021 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.                */
-/*************************************************************************/
-
-#if defined(UNIX_ENABLED) || defined(PTHREAD_ENABLED)
-
-#include "rw_lock_posix.h"
-
-#include "core/error_macros.h"
-#include "core/os/memory.h"
-#include <stdio.h>
-
-void RWLockPosix::read_lock() {
-
-	int err = pthread_rwlock_rdlock(&rwlock);
-	if (err != 0) {
-		perror("Acquiring lock failed");
-	}
-	ERR_FAIL_COND(err != 0);
-}
-
-void RWLockPosix::read_unlock() {
-
-	pthread_rwlock_unlock(&rwlock);
-}
-
-Error RWLockPosix::read_try_lock() {
-
-	if (pthread_rwlock_tryrdlock(&rwlock) != 0) {
-		return ERR_BUSY;
-	} else {
-		return OK;
-	}
-}
-
-void RWLockPosix::write_lock() {
-
-	int err = pthread_rwlock_wrlock(&rwlock);
-	ERR_FAIL_COND(err != 0);
-}
-
-void RWLockPosix::write_unlock() {
-
-	pthread_rwlock_unlock(&rwlock);
-}
-
-Error RWLockPosix::write_try_lock() {
-	if (pthread_rwlock_trywrlock(&rwlock) != 0) {
-		return ERR_BUSY;
-	} else {
-		return OK;
-	}
-}
-
-RWLock *RWLockPosix::create_func_posix() {
-
-	return memnew(RWLockPosix);
-}
-
-void RWLockPosix::make_default() {
-
-	create_func = create_func_posix;
-}
-
-RWLockPosix::RWLockPosix() {
-
-	//rwlock=PTHREAD_RWLOCK_INITIALIZER; fails on OSX
-	pthread_rwlock_init(&rwlock, NULL);
-}
-
-RWLockPosix::~RWLockPosix() {
-
-	pthread_rwlock_destroy(&rwlock);
-}
-
-#endif
diff --git a/drivers/unix/rw_lock_posix.h b/drivers/unix/rw_lock_posix.h
deleted file mode 100644
index 513d84a9c8b..00000000000
--- a/drivers/unix/rw_lock_posix.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/*************************************************************************/
-/*  rw_lock_posix.h                                                      */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                      https://godotengine.org                          */
-/*************************************************************************/
-/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2021 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 RWLOCKPOSIX_H
-#define RWLOCKPOSIX_H
-
-#if defined(UNIX_ENABLED) || defined(PTHREAD_ENABLED)
-
-#include "core/os/rw_lock.h"
-#include <pthread.h>
-
-class RWLockPosix : public RWLock {
-
-	pthread_rwlock_t rwlock;
-
-	static RWLock *create_func_posix();
-
-public:
-	virtual void read_lock();
-	virtual void read_unlock();
-	virtual Error read_try_lock();
-
-	virtual void write_lock();
-	virtual void write_unlock();
-	virtual Error write_try_lock();
-
-	static void make_default();
-
-	RWLockPosix();
-
-	~RWLockPosix();
-};
-
-#endif
-
-#endif // RWLOCKPOSIX_H
diff --git a/drivers/windows/rw_lock_windows.cpp b/drivers/windows/rw_lock_windows.cpp
deleted file mode 100644
index db29d0d1c5b..00000000000
--- a/drivers/windows/rw_lock_windows.cpp
+++ /dev/null
@@ -1,95 +0,0 @@
-/*************************************************************************/
-/*  rw_lock_windows.cpp                                                  */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                      https://godotengine.org                          */
-/*************************************************************************/
-/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2021 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.                */
-/*************************************************************************/
-
-#if defined(WINDOWS_ENABLED)
-
-#include "rw_lock_windows.h"
-
-#include "core/error_macros.h"
-#include "core/os/memory.h"
-
-#include <stdio.h>
-
-void RWLockWindows::read_lock() {
-
-	AcquireSRWLockShared(&lock);
-}
-
-void RWLockWindows::read_unlock() {
-
-	ReleaseSRWLockShared(&lock);
-}
-
-Error RWLockWindows::read_try_lock() {
-
-	if (TryAcquireSRWLockShared(&lock) == 0) {
-		return ERR_BUSY;
-	} else {
-		return OK;
-	}
-}
-
-void RWLockWindows::write_lock() {
-
-	AcquireSRWLockExclusive(&lock);
-}
-
-void RWLockWindows::write_unlock() {
-
-	ReleaseSRWLockExclusive(&lock);
-}
-
-Error RWLockWindows::write_try_lock() {
-	if (TryAcquireSRWLockExclusive(&lock) == 0) {
-		return ERR_BUSY;
-	} else {
-		return OK;
-	}
-}
-
-RWLock *RWLockWindows::create_func_windows() {
-
-	return memnew(RWLockWindows);
-}
-
-void RWLockWindows::make_default() {
-
-	create_func = create_func_windows;
-}
-
-RWLockWindows::RWLockWindows() {
-
-	InitializeSRWLock(&lock);
-}
-
-RWLockWindows::~RWLockWindows() {
-}
-
-#endif
diff --git a/drivers/windows/rw_lock_windows.h b/drivers/windows/rw_lock_windows.h
deleted file mode 100644
index b91495f4ec0..00000000000
--- a/drivers/windows/rw_lock_windows.h
+++ /dev/null
@@ -1,64 +0,0 @@
-/*************************************************************************/
-/*  rw_lock_windows.h                                                    */
-/*************************************************************************/
-/*                       This file is part of:                           */
-/*                           GODOT ENGINE                                */
-/*                      https://godotengine.org                          */
-/*************************************************************************/
-/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
-/* Copyright (c) 2014-2021 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 RWLOCKWINDOWS_H
-#define RWLOCKWINDOWS_H
-
-#if defined(WINDOWS_ENABLED)
-
-#include "core/os/rw_lock.h"
-
-#include <windows.h>
-
-class RWLockWindows : public RWLock {
-
-	SRWLOCK lock;
-
-	static RWLock *create_func_windows();
-
-public:
-	virtual void read_lock();
-	virtual void read_unlock();
-	virtual Error read_try_lock();
-
-	virtual void write_lock();
-	virtual void write_unlock();
-	virtual Error write_try_lock();
-
-	static void make_default();
-
-	RWLockWindows();
-
-	~RWLockWindows();
-};
-
-#endif
-
-#endif // RWLOCKWINDOWS_H
diff --git a/main/main.cpp b/main/main.cpp
index f9c50617ea5..5d189d53d14 100644
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -352,8 +352,6 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 
 	engine = memnew(Engine);
 
-	ClassDB::init();
-
 	MAIN_PRINT("Main: Initialize CORE");
 
 	register_core_types();
diff --git a/platform/osx/detect.py b/platform/osx/detect.py
index ea2189c031c..3572fae2169 100644
--- a/platform/osx/detect.py
+++ b/platform/osx/detect.py
@@ -85,8 +85,8 @@ def configure(env):
         env.Append(LINKFLAGS=["-arch", "arm64", "-mmacosx-version-min=10.15"])
     else:
         print("Building for macOS 10.9+, platform x86-64.")
-        env.Append(CCFLAGS=["-arch", "x86_64", "-mmacosx-version-min=10.9"])
-        env.Append(LINKFLAGS=["-arch", "x86_64", "-mmacosx-version-min=10.9"])
+        env.Append(CCFLAGS=["-arch", "x86_64", "-mmacosx-version-min=10.12"])
+        env.Append(LINKFLAGS=["-arch", "x86_64", "-mmacosx-version-min=10.12"])
 
     if not "osxcross" in env:  # regular native build
         if env["macports_clang"] != "no":
diff --git a/platform/uwp/os_uwp.cpp b/platform/uwp/os_uwp.cpp
index 15f6627cf1e..268010f0a00 100644
--- a/platform/uwp/os_uwp.cpp
+++ b/platform/uwp/os_uwp.cpp
@@ -41,7 +41,6 @@
 #include "drivers/windows/dir_access_windows.h"
 #include "drivers/windows/file_access_windows.h"
 #include "drivers/windows/mutex_windows.h"
-#include "drivers/windows/rw_lock_windows.h"
 #include "drivers/windows/semaphore_windows.h"
 #include "main/main.h"
 #include "platform/windows/windows_terminal_logger.h"
@@ -143,7 +142,6 @@ void OS_UWP::initialize_core() {
 	ThreadUWP::make_default();
 	SemaphoreWindows::make_default();
 	MutexWindows::make_default();
-	RWLockWindows::make_default();
 
 	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_RESOURCES);
 	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_USERDATA);
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index e077f32a55d..09084265d17 100755
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -41,7 +41,6 @@
 #include "drivers/windows/dir_access_windows.h"
 #include "drivers/windows/file_access_windows.h"
 #include "drivers/windows/mutex_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"
@@ -230,7 +229,6 @@ void OS_Windows::initialize_core() {
 	ThreadWindows::make_default();
 	SemaphoreWindows::make_default();
 	MutexWindows::make_default();
-	RWLockWindows::make_default();
 
 	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_RESOURCES);
 	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_USERDATA);
diff --git a/scene/resources/texture.cpp b/scene/resources/texture.cpp
index 03e5a676d93..17e67c2a20c 100644
--- a/scene/resources/texture.cpp
+++ b/scene/resources/texture.cpp
@@ -2218,19 +2218,10 @@ AnimatedTexture::AnimatedTexture() {
 	pause = false;
 	oneshot = false;
 	VisualServer::get_singleton()->connect("frame_pre_draw", this, "_update_proxy");
-
-#ifndef NO_THREADS
-	rw_lock = RWLock::create();
-#else
-	rw_lock = NULL;
-#endif
 }
 
 AnimatedTexture::~AnimatedTexture() {
 	VS::get_singleton()->free(proxy);
-	if (rw_lock) {
-		memdelete(rw_lock);
-	}
 }
 ///////////////////////////////
 
diff --git a/scene/resources/texture.h b/scene/resources/texture.h
index 9ee35ee13eb..13d95283b60 100644
--- a/scene/resources/texture.h
+++ b/scene/resources/texture.h
@@ -679,7 +679,7 @@ class AnimatedTexture : public Texture {
 	GDCLASS(AnimatedTexture, Texture);
 
 	//use readers writers lock for this, since its far more times read than written to
-	RWLock *rw_lock;
+	RWLock rw_lock;
 
 public:
 	enum {