AsyncSemaphore

The AsyncSemaphore is an asynchronous semaphore implementation that limits the parallelism on Future execution.

The following example instantiates a semaphore with a maximum parallelism of 10:

val semaphore = AsyncSemaphore(maxParallelism = 10)

def makeRequest(r: HttpRequest): Future[HttpResponse] = ???

// For such a task no more than 10 requests
// are allowed to be executed in parallel.
val future = semaphore.greenLight(() => makeRequest(???))

Linear Supertypes

Serializable, Serializable, AnyRef, Any

Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def acquire(): CancelableFuture[Unit]

Triggers a permit acquisition, returning a future that will complete when a permit gets acquired.
Triggers a permit acquisition, returning a future that will complete when a permit gets acquired.

Annotations
@tailrec()
def activeCount: Int

Returns the number of active tasks that are holding on to the available permits.
final def asInstanceOf[T0]: T0

Definition Classes
Any
def awaitAllReleased(): Future[Unit]

Returns a future that will be complete when all the currently acquired permits are released, or in other words when the activeCount is zero.
Returns a future that will be complete when all the currently acquired permits are released, or in other words when the activeCount is zero.
This also means that we are going to wait for the acquisition and release of all enqueued promises as well.

Annotations
@tailrec()
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def greenLight[A](f: () ⇒ Future[A])(implicit ec: ExecutionContext): Future[A]

Returns a new future, ensuring that the given source acquires an available permit from the semaphore before it is executed.
Returns a new future, ensuring that the given source acquires an available permit from the semaphore before it is executed.
The returned future also takes care of resource handling, releasing its permit after being complete.
f
is a function returning the Future instance we want to evaluate after we get the permit from the semaphore
def hashCode(): Int

Definition Classes
AnyRef → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
def release(): Unit

Releases a permit, returning it to the pool.
Releases a permit, returning it to the pool.
If there are consumers waiting on permits being available, then the first in the queue will be selected and given a permit immediately.

Annotations
@tailrec()
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def toString(): String

Definition Classes
AnyRef → Any
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

Related Docs: object AsyncSemaphore | package misc

final class AsyncSemaphore extends Serializable

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

def acquire(): CancelableFuture[Unit]

def activeCount: Int

final def asInstanceOf[T0]: T0

def awaitAllReleased(): Future[Unit]

def clone(): AnyRef

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def greenLight[A](f: () ⇒ Future[A])(implicit ec: ExecutionContext): Future[A]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

def release(): Unit

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from Serializable

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped