You can't really compare thread pools to semaphores. They're don't have the same intended use, where semaphores are a low-level synchronization mechanism and t

You can't really compare thread pools to semaphores. They're don't have the same intended use, where semaphores are a low-level synchronization mechanism and thread pools are a bit higher up. In fact, I would wager that many, if not most, implementations of thread pools use semaphores to some degree.