Packages

object Concurrent extends Serializable

Source
Concurrent.scala
Linear Supertypes
Serializable, AnyRef, Any
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. Concurrent
  2. Serializable
  3. AnyRef
  4. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

Type Members

  1. trait AllOps[F[_], A] extends Ops[F, A] with Async.AllOps[F, A]
  2. trait Ops[F[_], A] extends AnyRef
  3. trait ToConcurrentOps extends AnyRef

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. def apply[F[_]](implicit instance: Concurrent[F]): Concurrent[F]
    Annotations
    @inline()
  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. def cancelableF[F[_], A](k: ((Either[Throwable, A]) => Unit) => F[CancelToken[F]])(implicit F: Concurrent[F]): F[A]

    Function that creates an async and cancelable F[A], similar with Concurrent.cancelable, but with the semantics of Async.asyncF.

    Function that creates an async and cancelable F[A], similar with Concurrent.cancelable, but with the semantics of Async.asyncF.

    Example building an asynchronous queue, with the state being kept in cats.effect.concurrent.Ref and thus needing cancelableF:

    import cats.implicits._
    import cats.effect.{CancelToken, Concurrent}
    import cats.effect.concurrent.Ref
    import scala.collection.immutable.Queue
    
    final class AsyncQueue[F[_], A] private (
      ref: Ref[F, AsyncQueue.State[A]])
      (implicit F: Concurrent[F]) {
    
      import AsyncQueue._
    
      def poll: F[A] =
        Concurrent.cancelableF { cb =>
          ref.modify {
            case Await(listeners) =>
              (Await(listeners.enqueue(cb)), F.pure(unregister(cb)))
            case Available(queue) =>
              queue.dequeueOption match {
                case None =>
                  (Await(Queue(cb)), F.pure(unregister(cb)))
                case Some((a, queue2)) =>
                  (Available(queue2), F.delay(cb(Right(a))).as(unregister(cb)))
              }
          }.flatten
        }
    
      def offer(a: A): F[Unit] = {
        // Left as an exercise for the reader ;-)
        ???
      }
    
      private def unregister(cb: Either[Throwable, A] => Unit): CancelToken[F] =
        ref.update {
          case Await(listeners) => Await(listeners.filter(_ != cb))
          case other => other
        }
    }
    
    object AsyncQueue {
      def empty[F[_], A](implicit F: Concurrent[F]): F[AsyncQueue[F, A]] =
        for {
          ref <- Ref.of[F, State[A]](Available(Queue.empty))
        } yield {
          new AsyncQueue[F, A](ref)
        }
    
      private sealed trait State[A]
    
      private case class Await[A](listeners: Queue[Either[Throwable, A] => Unit])
        extends State[A]
    
      private case class Available[A](values: Queue[A])
        extends State[A]
    }

    Contract

    The given generator function will be executed uninterruptedly, via bracket, because due to the possibility of auto-cancellation we can have a resource leak otherwise.

    This means that the task generated by k cannot be cancelled while being evaluated. This is in contrast with Async.asyncF, which does allow cancelable tasks.

    k

    is a function that's going to be injected with a callback, to call on completion, returning an effect that's going to be evaluated to a cancellation token

  7. implicit def catsEitherTConcurrent[F[_], L](implicit arg0: Concurrent[F]): Concurrent[[γ$0$]EitherT[F, L, γ$0$]]

    Concurrent instance built for cats.data.EitherT values initialized with any F data type that also implements Concurrent.

  8. implicit def catsIorTConcurrent[F[_], L](implicit arg0: Concurrent[F], arg1: Semigroup[L]): Concurrent[[γ$4$]IorT[F, L, γ$4$]]

    Concurrent instance built for cats.data.IorT values initialized with any F data type that also implements Concurrent.

  9. implicit def catsKleisliConcurrent[F[_], R](implicit arg0: Concurrent[F]): Concurrent[[γ$2$]Kleisli[F, R, γ$2$]]

    Concurrent instance built for cats.data.Kleisli values initialized with any F data type that also implements Concurrent.

  10. implicit def catsOptionTConcurrent[F[_]](implicit arg0: Concurrent[F]): Concurrent[[β$1$]OptionT[F, β$1$]]

    Concurrent instance built for cats.data.OptionT values initialized with any F data type that also implements Concurrent.

  11. implicit def catsWriterTConcurrent[F[_], L](implicit arg0: Concurrent[F], arg1: Monoid[L]): Concurrent[[γ$3$]WriterT[F, L, γ$3$]]

    Concurrent instance built for cats.data.WriterT values initialized with any F data type that also implements Concurrent.

  12. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  13. def continual[F[_], A, B](fa: F[A])(f: (Either[Throwable, A]) => F[B])(implicit F: Concurrent[F]): F[B]

    This is the default Concurrent.continual implementation.

  14. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  15. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  16. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  17. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  18. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  19. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  20. def liftIO[F[_], A](ioa: IO[A])(implicit F: Concurrent[F]): F[A]

    Lifts any IO value into any data type implementing Concurrent.

    Lifts any IO value into any data type implementing Concurrent.

    Compared with Async.liftIO, this version preserves the interruptibility of the given IO value.

    This is the default Concurrent.liftIO implementation.

  21. def memoize[F[_], A](f: F[A])(implicit F: Concurrent[F]): F[F[A]]

    Lazily memoizes f.

    Lazily memoizes f. Assuming no cancellation happens, the effect f will be performed at most once for every time the returned F[F[A]] is bound (when the inner F[A] is bound the first time).

    If you try to cancel an inner F[A], f is only interrupted if there are no other active subscribers, whereas if there are, f keeps running in the background.

    If f is successfully canceled, the next time an inner F[A] is bound f will be restarted again. Note that this can mean the effects of f happen more than once.

    You can look at Async.memoize for a version of this function which does not allow cancellation.

  22. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  23. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  24. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  25. def parSequenceN[T[_], M[_], A](n: Long)(tma: T[M[A]])(implicit arg0: Traverse[T], M: Concurrent[M], P: Parallel[M]): M[T[A]]

    Like Parallel.parSequence, but limits the degree of parallelism.

  26. def parTraverseN[T[_], M[_], A, B](n: Long)(ta: T[A])(f: (A) => M[B])(implicit arg0: Traverse[T], M: Concurrent[M], P: Parallel[M]): M[T[B]]

    Like Parallel.parTraverse, but limits the degree of parallelism.

  27. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  28. def timeout[F[_], A](fa: F[A], duration: FiniteDuration)(implicit F: Concurrent[F], timer: Timer[F]): F[A]

    Returns an effect that either completes with the result of the source within the specified time duration or otherwise raises a TimeoutException.

    Returns an effect that either completes with the result of the source within the specified time duration or otherwise raises a TimeoutException.

    The source is cancelled in the event that it takes longer than the specified time duration to complete.

    duration

    is the time span for which we wait for the source to complete; in the event that the specified time has passed without the source completing, a TimeoutException is raised

  29. def timeoutTo[F[_], A](fa: F[A], duration: FiniteDuration, fallback: F[A])(implicit F: Concurrent[F], timer: Timer[F]): F[A]

    Returns an effect that either completes with the result of the source within the specified time duration or otherwise evaluates the fallback.

    Returns an effect that either completes with the result of the source within the specified time duration or otherwise evaluates the fallback.

    The source is cancelled in the event that it takes longer than the FiniteDuration to complete, the evaluation of the fallback happening immediately after that.

    duration

    is the time span for which we wait for the source to complete; in the event that the specified time has passed without the source completing, the fallback gets evaluated

    fallback

    is the task evaluated after the duration has passed and the source canceled

  30. def toString(): String
    Definition Classes
    AnyRef → Any
  31. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  32. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  33. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()
  34. object nonInheritedOps extends ToConcurrentOps
  35. object ops

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped