What is the difference between a "semaphore" and a "monitor"?

Question

Accepted Answer

Semaphore and monitor are synchronization tools used in concurrent programming.

Semaphore is a signaling mechanism that allows multiple threads to access a shared resource simultaneously.
Monitor is a synchronization construct that allows threads to have both mutual exclusion and the ability to wait (block) for a certain condition to become true.
Semaphore is a lower-level primitive, while monitor is a higher-level abstraction.
Semaphore can be used to implement a monitor.
Example of semaphore: counting semaphore, binary semaphore.
Example of monitor: Java synchronized keyword, C# lock statement.

Accepted Answer

A semaphore is a signaling mechanism used to coordinate between threads. A mutex (mutual exclusion lock) is a lock which is owned by a single thread. A monitor is a higher-level construct which uses an underlying mutex lock to ensure thread-safe access to some object.

What is the difference between a "semaphore" and a "monitor"?

Top Cognizant Full Stack Software Developer interview questions & answers

Popular interview questions of Full Stack Software Developer

Top HR questions asked in Cognizant Full Stack Software Developer