Package-level declarations

Mutual exclusion for coroutines.

A counting semaphore for coroutines that logically maintains a number of available permits. Each acquire takes a single permit or suspends until it is available. Each release adds a permit, potentially releasing a suspended acquirer. Semaphore is fair and maintains a FIFO order of acquirers.

Creates a Mutex instance. The mutex created is fair: lock is granted in first come, first served order.

Creates new Semaphore instance.

Executes the given action under this mutex's lock.

Executes the given action, acquiring a permit from this semaphore at the beginning and releasing it after the action is completed.