Editing Semaphore (programming) (section)

==Semaphores vs. mutexes==
A [[mutex]] is a [[Mutual exclusion#Types of mutual exclusion devices|locking mechanism]] that sometimes uses the same basic implementation as the binary semaphore. However, they differ in how they are used. While a binary semaphore may be colloquially referred to as a mutex, a true mutex has a more specific use-case and definition, in that only the [[Task (computing)|task]] that locked the mutex is supposed to unlock it. This constraint aims to handle some potential problems of using semaphores:
# [[Priority inversion]]: If the mutex knows who locked it and is supposed to unlock it, it is possible to promote the priority of that task whenever a higher-priority task starts waiting on the mutex.
# Premature task termination: Mutexes may also provide deletion safety, where the task holding the mutex cannot be accidentally deleted. {{citation needed|date=May 2019}}  (This is also a cost; if the mutex can prevent a task from being reclaimed, then a garbage collector has to monitor the mutex.)
# Termination deadlock: If a mutex-holding task terminates for any reason, the [[Real-time operating system|OS]] can release the mutex and signal waiting tasks of this condition.
# Recursion deadlock: a task is allowed to lock a [[reentrant mutex]] multiple times as it unlocks it an equal number of times.
# Accidental release: An error is raised on the release of the mutex if the releasing task is not its owner.