Conditional Variable Vs Semaphore
Answer : Locks are used for mutual exclusion. When you want to ensure that a piece of code is atomic, put a lock around it. You could theoretically use a binary semaphore to do this, but that's a special case. Semaphores and condition variables build on top of the mutual exclusion provide by locks and are used for providing synchronized access to shared resources. They can be used for similar purposes. A condition variable is generally used to avoid busy waiting (looping repeatedly while checking a condition) while waiting for a resource to become available. For instance, if you have a thread (or multiple threads) that can't continue onward until a queue is empty, the busy waiting approach would be to just doing something like: //pseudocode while(!queue.empty()) { sleep(1); } The problem with this is that you're wasting processor time by having this thread repeatedly check the condition. Why not instead have a synchronization variable that can be signaled to tel...