What is the difference between lock, mutex and semaphore?

A lock allows only one thread to enter the part that’s locked and the lock is not shared with any other processes.

A mutex is the same as a lock but it can be system wide (shared by multiple processes).

A semaphore does the same as a mutex but allows x number of threads to enter, this can be used for example to limit the number of cpu, io or ram intensive tasks running at the same time.

For a more detailed post about the differences between mutex and semaphore read here.

You also have read/write locks that allows either unlimited number of readers or 1 writer at any given time.

Related Posts:

  1. What is the difference between lock, mutex and semaphore?
  2. What is a mutex?
  3. What is a database transaction?
  4. Difference between binary semaphore and mutex
  5. What’s the difference between the message passing and shared memory concurrency models?
  6. Is there a Mutex in Java?
  7. What is a coroutine?
  8. What is a race condition?
  9. pthread_join() and pthread_exit()
  10. Mutex example / tutorial? [closed]
  11. What does a lock statement do under the hood?
  12. What is the meaning of the term “thread-safe”?
  13. What is the difference between concurrency and parallelism?
  14. What are atomic operations for newbies?
  15. Optimistic vs. Pessimistic locking
  16. Is there a concurrent List in Java’s JDK?
  17. Collection was modified; enumeration operation may not execute
  18. Choosing the best concurrency list in Java
  19. Proper use of mutexes in Python
  20. Undefined Reference issues using Semaphores
  21. Semaphore vs. Monitors – what’s the difference?
  22. PTHREAD_MUTEX_INITIALIZER vs pthread_mutex_init ( &mutex, param)
  23. LINK : fatal error LNK1104: cannot open file ‘D:\…\MyProj.exe’

Leave a Comment