synchronization mechanism in linux

Linux supports the following synchronization mechanisms:

• Critical Section A critical section is a piece of code that may be accessed only by a single thread at a time, for example a code segment that changes a shared variable.

• Mutual Exclusion A mutual exclusion (mutex for short) is an object that restricts access to a variable or code section to a single thread at a time. Thus, you may use a mutex to protect a critical code section.

• Semaphores A semaphore restricts access to a variable or object to a limited number of threads. For example, a semaphore may be used to ensure that three threads at most access a system's clock.