Aug 29, 2008 · A semaphore is a programming concept that is frequently used to solve multi-threading problems. My question to the community: What is a semaphore and how do you use it?

Feb 25, 2010 · I've heard these words related to concurrent programming, but what's the difference between lock, mutex and semaphore?

Apr 27, 2025 · In general, mutex and semaphore target different use cases: A semaphore is for signalling, a mutex is for mutual exclusion. Mutual exclusion means you want to make sure that …

Here is how I remember when to use what - Semaphore: Use a semaphore when you (thread) want to sleep till some other thread tells you to wake up. Semaphore 'down' happens in one thread …

Aug 3, 2009 · The Java Semaphore class allows a reverse situation, where a semaphore can start off with a negative number of permits, and all acquire() calls will fail until there have been enough …

Jul 20, 2015 · I've started programming in Python a few weeks ago and was trying to use Semaphores to synchronize two simple threads, for learning purposes. Here is what I've got: import threading sem …

Apr 8, 2011 · For multithreaded programming, semaphores should be avoided. If you need exclusive access to a resource, use mutex. If you need to wait for a signal, use condition variable. Even the …

Feb 15, 2014 · I think you're having trouble with the distinction between a semaphore and a mutex. A binary semaphore can be implemented in the same way as a mutex, but they are actually for …

Apr 21, 2009 · Ownership is incredibly important for safe programming of concurrent systems. I would always recommend using mutex in preference to a semaphore (but there are performance …

Apr 7, 2017 · The sem_signal helper just adds 1 to the semaphore value (uses semop under the hood). I'd like the code to alternate between the two processes, using sem_wait to block until the other …