Mutexes

A mutex (MUTually EXclusive) is a coroutine specific synchronisation primitive. It is used for managing access to shared resources such that only 1 coroutine can access the resource at any given time.

The mutex has the following properties:

• Must be called within a coroutine only, ISRs, code executed outside the scheduler cannot use the mutex. For synchronisation is required for these cases, see Semaphores instead.

• Can be called multiple times within the same coroutine.

This functionality is available from the specific header <poco/mutex.h>.

Creating a Mutex

Mutexes are created by using either the static or dynamic constructors, mutex_create_static() and mutex_create() respectively.

Acquiring and Releasing

To use the mutex, it much first be acquired. If acquired, it guarantees that all other coroutines attempting to acquire the mutex will be blocked until it is released.

Warning

Failure to release the mutex will cause a deadlock, where all other coroutines will wait their defined timeout.

No Wait Variants

The mutex supoprts a no wait variant acquiring the mutex.