How does a mutex differ from a semaphore?
How does a mutex differ from a semaphore?
243
06-Mar-2025
Updated on 08-Mar-2025
Khushi Singh
08-Mar-2025Both multithreading uses mutex mutual exclusion and semaphore as synchronization tools although these tools operate differently according to their usage cases. The main function of a mutex is to enable one thread access while blocking all other simultaneous attempts at accessing the shared resource. Threads need to obtain the mutex before running their critical section and must free it afterward. The resource becomes inaccessible for other threads that attempt to access it because the mutex remains locked thus requiring them to wait until the mutex is released. The exclusive access of a single thread to shared data ensures the prevention of race conditions.
A semaphore functions as a versatile synchronization device because it lets threads access resources concurrently. Counter operations with semaphores differ from mutexes since they encompass both locked and unlocked states. The value of binary semaphores can be either 0 or 1 thereby acting like a mutex to grant access to only one thread at once. A counting semaphore provides the possibility for multiple threads to access the critical section simultaneously according to a specified allowed number. A semaphore enables three threads to access the shared resource before blocking further threads because its initial value was set to three.
The main distinction between mutexes and semaphores emerges from their different approach to resource management. Because of its requirements for exclusive control assets only the thread that initiated execution of the mutex is able to perform the unlocking operation. A semaphore implements count operations between threads because different threads may increase or decrease the number to support access resource coordination. Exclusive access control functions best with mutexes whereas semaphores provide better resource counting and concurrent access limiting. multiprocessing application efficiency requires a complete grasp of semaphore and mutex characteristics.