Semaphore
Related Docs:
object Semaphore
| package concurrent
Acquires n permits.
Acquires n permits.
The returned effect semantically blocks until all requested permits are
available. Note that acquires are statisfied in strict FIFO order, so given
s: Semaphore[F] with 2 permits available, an acquireN(3) will
always be satisfied before a later call to acquireN(1).
number of permits to acquire - must be >= 0
Returns the number of permits currently available.
Returns the number of permits currently available. Always non-negative.
May be out of date the instant after it is retrieved.
Use tryAcquire or tryAcquireN if you wish to attempt an
acquire, returning immediately if the current count is not high enough
to satisfy the request.
Obtains a snapshot of the current count.
Obtains a snapshot of the current count. May be negative.
Like available when permits are available but returns the number of permits callers are waiting for when there are no permits available.
Releases n permits, potentially unblocking up to n outstanding acquires.
Releases n permits, potentially unblocking up to n outstanding acquires.
number of permits to release - must be >= 0
Acquires n permits now and returns true, or returns false immediately.
Acquires n permits now and returns true, or returns false immediately. Error if n < 0.
number of permits to acquire - must be >= 0
Returns an effect that acquires a permit, runs the supplied effect, and then releases the permit.
Acquires a single permit.
Acquires a single permit. Alias for acquireN(1).
Releases a single permit.
Releases a single permit. Alias for releaseN(1).
Alias for tryAcquireN(1).
A purely functional semaphore.
A semaphore has a non-negative number of permits available. Acquiring a permit decrements the current number of permits and releasing a permit increases the current number of permits. An acquire that occurs when there are no permits available results in semantic blocking until a permit becomes available.
Blocking acquires are cancelable if the semaphore is created with
Semaphore.apply(and hence, with aConcurrent[F]instance). Blocking acquires are non-cancelable if the semaphore is created withSemaphore.async(and hence, with anAsync[F]instance).