In a multithreaded environment where memory, peripherals, and system accesses are shared, a system should provide synchronization mechanisms to allow the tasks to cooperate on the arbitration of the access to system-wide available resources.

Mutexes and semaphores are two of the most commonly used mechanisms of synchronization between parallel threads, as they provide the minimal set to solve most of the concurrency problems. Functions that could block the calling tasks must be able to interact with the scheduler, to move the task in the waiting state whenever the resource is not available, until the lock is released or the semaphore is incremented.