Class OperatorPublish.InnerProducer<T>

java.lang.Object
java.lang.Number
java.util.concurrent.atomic.AtomicLong
rx.internal.operators.OperatorPublish.InnerProducer<T>
Type Parameters:
T - the value type
All Implemented Interfaces:
Serializable, Producer, Subscription
Enclosing class:
OperatorPublish<T>

static final class OperatorPublish.InnerProducer<T> extends AtomicLong implements Producer, Subscription
A Producer and Subscription that manages the request and unsubscription state of a child subscriber in thread-safe manner. We use AtomicLong as a base class to save on extra allocation of an AtomicLong and also save the overhead of the AtomicIntegerFieldUpdater.
  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      See Also:
    • parent

      The parent subscriber-to-source used to allow removing the child in case of child unsubscription.
    • child

      final Subscriber<? super T> child
      The actual child subscriber.
    • UNSUBSCRIBED

      static final long UNSUBSCRIBED
      Indicates this child has been unsubscribed: the state is swapped in atomically and will prevent the dispatch() to emit (too many) values to a terminated child subscriber.
      See Also:
    • NOT_REQUESTED

      static final long NOT_REQUESTED
      Indicates this child has not yet requested any value. We pretend we don't see such child subscribers in dispatch() to allow other child subscribers who have requested to make progress. In a concurrent subscription scenario, one can't be sure when a subscription happens exactly so this virtual shift should not cause any problems.
      See Also:
  • Constructor Details

  • Method Details

    • request

      public void request(long n)
      Description copied from interface: Producer
      Request a certain maximum number of items from this Producer. This is a way of requesting backpressure. To disable backpressure, pass Long.MAX_VALUE to this method.

      Requests are additive but if a sequence of requests totals more than Long.MAX_VALUE then Long.MAX_VALUE requests will be actioned and the extras may be ignored. Arriving at Long.MAX_VALUE by addition of requests cannot be assumed to disable backpressure. For example, the code below may result in Long.MAX_VALUE requests being actioned only.

       request(100);
       request(Long.MAX_VALUE-1);
       
      Specified by:
      request in interface Producer
      Parameters:
      n - the maximum number of items you want this Producer to produce, or Long.MAX_VALUE if you want the Producer to produce items at its own pace
    • produced

      public long produced(long n)
      Indicate that values have been emitted to this child subscriber by the dispatch() method.
      Parameters:
      n - the number of items emitted
      Returns:
      the updated request value (may indicate how much can be produced or a terminal state)
    • isUnsubscribed

      public boolean isUnsubscribed()
      Description copied from interface: Subscription
      Indicates whether this Subscription is currently unsubscribed.
      Specified by:
      isUnsubscribed in interface Subscription
      Returns:
      true if this Subscription is currently unsubscribed, false otherwise
    • unsubscribe

      public void unsubscribe()
      Description copied from interface: Subscription
      Stops the receipt of notifications on the Subscriber that was registered when this Subscription was received.

      This allows unregistering an Subscriber before it has finished receiving all events (i.e. before onCompleted is called).

      Specified by:
      unsubscribe in interface Subscription