Mutex can also be referred to as Binary Semaphore



A Mutex is a synchronization primitive that is used to protect shared resources from simultaneous access by multiple threads or processes. It ensures that only one thread can access the shared resource at a time.

Mutexes are implemented using a binary semaphore, which is a variant of a semaphore that can take only two values: 0 and 1. The binary semaphore is used to control access to the critical section of code by allowing or blocking threads based on the value of the semaphore.

Binary Semaphore:
A binary semaphore is a synchronization primitive that can take only two values - 0 and 1. It is used to control access to a shared resource by multiple threads or processes. When the semaphore value is 0, it means the resource is currently being used and any other thread or process that wants to access it must wait. When the semaphore value is 1, it means the resource is available and can be accessed by a thread or process.

Mutex:
A mutex is a mutual exclusion object that is used to protect shared resources from simultaneous access by multiple threads or processes. It provides exclusive access to the critical section of code, allowing only one thread or process to execute it at a time. A mutex has two possible states - locked and unlocked. When a thread or process acquires a mutex, it locks it and gains exclusive access to the critical section. Other threads or processes that try to acquire the mutex while it is locked must wait until it is released.

Relation between Mutex and Binary Semaphore:
A mutex and a binary semaphore are similar in functionality and can be used interchangeably in many cases. Both provide mutual exclusion and can be used to synchronize access to shared resources. However, there are some subtle differences between them:

1. Ownership: A mutex can be owned by the thread that locked it, which means only the thread that locked the mutex can unlock it. On the other hand, a binary semaphore can be unlocked by any thread or process, regardless of which thread or process locked it.

2. Blocking vs Non-blocking: When a thread tries to acquire a locked mutex, it blocks and waits until the mutex is released. In contrast, a binary semaphore can be acquired in a non-blocking manner, which means the thread does not block and continues execution even if the semaphore is locked.

3. Counting vs Binary: A mutex is a binary synchronization primitive, meaning it can take only two values - locked or unlocked. In contrast, a binary semaphore can be used as a counting semaphore, which can take any non-negative integer value.

Conclusion:
In summary, a mutex can be referred to as a binary semaphore because it provides mutual exclusion and uses a binary semaphore for its implementation. However, it is important to note that a mutex has additional features like ownership and blocking behavior, which differentiate it from a simple binary semaphore.