5 files changed, 16 insertions, 51 deletions
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();