IO.Async.Semaphore

Definitions

record Semaphore : Type

  A semphore is a synchronization primitive that can
  be observed by at most one observer.
  
  It consists of an internal counter that is atomically
  reduced every time `release` is invoked.
  
  Calling `await` blocks the calling fiber until the
  semaphore's counter has been reduced to 0.

Totality: total
Visibility: export
Constructor: 

S : IORef ST -> Semaphore

Projection: 

.ref : Semaphore -> IORef ST

semaphore : Lift1 World f => Nat -> f Semaphore

  Creates a new semaphore with an internal counter of `n`.

Totality: total
Visibility: export

releaseN : HasIO io => Semaphore -> Nat -> io ()

  Atomically reduces the internal counter of the semaphore by the
  given number.

Totality: total
Visibility: export

release : HasIO io => Semaphore -> io ()

  Atomically reduces the internal counter of the semaphore by one.

Totality: total
Visibility: export

acquireN : Semaphore -> Nat -> Async e es ()

  Waits (possibly by semantically blocking the fiber)
  until the given number of steps have been released.
  
  Note: Currently, `Semaphore` values can only be observed
        by one observer. The calling fiber will block until
        canceled, if another fiber has called `await` already.

Totality: total
Visibility: export

acquire : Semaphore -> Async e es ()

  Alias for `acquireN 1`

Totality: total
Visibility: export