...
class Semaphore : NoCopy {
#ifdef PLATFORM_WIN32
	HANDLE     handle;
#elif PLATFORM_OSX
	dispatch_semaphore_t    sem;
#else
	sem_t      sem;
#endif

public:
	bool       Wait(int timeout_ms); // Added for timeout - returns true if semaphore was signaled, false otherwise
	void       Wait();
	void       Release();
#ifdef PLATFORM_WIN32
	void       Release(int n);
#endif

	Semaphore();
	~Semaphore();
};
...

...

// For Windows:
bool Semaphore::Wait(int timeout_ms)
{
	return WaitForSingleObject(handle, timeout_ms<0 ? INFINITE : timeout_ms) == WAIT_OBJECT_0 ? true : false;
}

...

// For Linux:
bool Semaphore::Wait(int timeout_ms)
{
	if(timeout_ms<0){
		Wait();
		return true;
	}
	
	struct timespec until;
	clock_gettime(CLOCK_REALTIME, &until);
	
	until.tv_sec+=timeout_ms/1000;
	timeout_ms%=1000;
	until.tv_nsec+=timeout_ms*1000000;
	until.tv_sec+=until.tv_nsec/1000000000;
	until.tv_nsec%=1000000000;
	
	return sem_timedwait(&sem,&until)==-1 ? false : true;
}
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...
bool Semaphore::Wait(int timeout_ms)
{ 
	if(timeout_ms<0){
		dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER);
		return true;
	}
	return dispatch_semaphore_wait(sem, dispatch_time(DISPATCH_TIME_NOW, 1000000 * timeout_ms)) == 0 ? true : false;
}
...