Difference Between Semaphore and Mutex

In this post, we will understand the difference between a semaphore and a mutex −

Semaphore

It is used in the signalling mechanism.
It is an integer variable.
The ‘wait’ and ‘signal’ operations can be used to modify a semaphore.
If no resources are available, the process requires that a resource that needs to be executed has to ‘wait’.
The process will have to ‘wait’ until the count of the semaphore is higher than 0.
Multiple program threads can be used with a semaphore.
The value of a semaphore can be changed by any process that releases or obtains the resource.
There are different kinds of semaphores: Counting semaphore and Binary semaphore.
The value of a semaphore can be changed using ‘wait’ operation and ‘signal’ operation.
The process is occupied if all resources are used.
The process requesting the resource uses the ‘wait’ operation and blocks itself until the count of the semaphore becomes greater than 1.

It is used in locking mechanism.
It is an object.
It is modified by that process (only) that requests or releases a resource.
If the mutex is locked, then the process will have to wait.
The process is kept in a queue when mutex s locked.
This can be accessed only after the mutex has been unlocked.
Multiple program threads can be used in mutex (but not simultaneously).
The lock on the object can be released by the process only, which would have obtained the lock on it.
It doesn’t have any subtypes.
The object is either locked or unlocked.
If the object has already been locked, the process that requests the resources will wait.
It will be queued by the system before the lock has been released.

Published on 20-Apr-2021 08:59:48