Class AbstractEmptyQueueFuseable<T>

java.lang.Object
io.reactivex.rxjava3.internal.fuseable.AbstractEmptyQueueFuseable<T>
Type Parameters:
T - the output value type
All Implemented Interfaces:
Disposable, QueueDisposable<T>, QueueFuseable<T>, QueueSubscription<T>, SimpleQueue<T>, org.reactivestreams.Subscription
Direct Known Subclasses:
CancellableQueueFuseable, FlowableFromCompletable.FromCompletableObserver, ObservableFromCompletable.FromCompletableObserver

public abstract class AbstractEmptyQueueFuseable<T> extends Object implements QueueSubscription<T>, QueueDisposable<T>
Represents an empty, async-only QueueFuseable instance.
Since:
3.0.0
  • Constructor Details

    • AbstractEmptyQueueFuseable

      public AbstractEmptyQueueFuseable()
  • Method Details

    • requestFusion

      public final int requestFusion(int mode)
      Description copied from interface: QueueFuseable
      Request a fusion mode from the upstream.

      This should be called before onSubscribe returns.

      Calling this method multiple times or after onSubscribe finished is not allowed and may result in undefined behavior.

      Specified by:
      requestFusion in interface QueueFuseable<T>
      Parameters:
      mode - the requested fusion mode, allowed values are QueueFuseable.SYNC, QueueFuseable.ASYNC, QueueFuseable.ANY combined with QueueFuseable.BOUNDARY (e.g., requestFusion(SYNC | BOUNDARY)).
      Returns:
      the established fusion mode: QueueFuseable.NONE, QueueFuseable.SYNC, QueueFuseable.ASYNC.
    • offer

      public final boolean offer(@NonNull T value)
      Description copied from interface: SimpleQueue
      Atomically enqueue a single value.
      Specified by:
      offer in interface SimpleQueue<T>
      Parameters:
      value - the value to enqueue, not null
      Returns:
      true if successful, false if the value was not enqueued likely due to reaching the queue capacity)
    • offer

      public final boolean offer(@NonNull T v1, @NonNull T v2)
      Description copied from interface: SimpleQueue
      Atomically enqueue two values.
      Specified by:
      offer in interface SimpleQueue<T>
      Parameters:
      v1 - the first value to enqueue, not null
      v2 - the second value to enqueue, not null
      Returns:
      true if successful, false if the value was not enqueued likely due to reaching the queue capacity)
    • poll

      public final T poll() throws Throwable
      Description copied from interface: SimpleQueue
      Tries to dequeue a value (non-null) or returns null if the queue is empty.

      If the producer uses SimpleQueue.offer(Object, Object) and when polling in pairs, if the first poll() returns a non-null item, the second poll() is guaranteed to return a non-null item as well.

      Specified by:
      poll in interface SimpleQueue<T>
      Returns:
      the item or null to indicate an empty queue
      Throws:
      Throwable - if some pre-processing of the dequeued item (usually through fused functions) throws.
    • isEmpty

      public final boolean isEmpty()
      Description copied from interface: SimpleQueue
      Returns true if the queue is empty.

      Note however that due to potential fused functions in SimpleQueue.poll() it is possible this method returns false but then poll() returns null because the fused function swallowed the available item(s).

      Specified by:
      isEmpty in interface SimpleQueue<T>
      Returns:
      true if the queue is empty
    • clear

      public final void clear()
      Description copied from interface: SimpleQueue
      Removes all enqueued items from this queue.
      Specified by:
      clear in interface SimpleQueue<T>
    • request

      public final void request(long n)
      Specified by:
      request in interface org.reactivestreams.Subscription
    • cancel

      public void cancel()
      Specified by:
      cancel in interface org.reactivestreams.Subscription
    • dispose

      public void dispose()
      Description copied from interface: Disposable
      Dispose the resource, the operation should be idempotent.
      Specified by:
      dispose in interface Disposable
    • isDisposed

      public boolean isDisposed()
      Description copied from interface: Disposable
      Returns true if this resource has been disposed.
      Specified by:
      isDisposed in interface Disposable
      Returns:
      true if this resource has been disposed