io.reactivex.rxjava3.operators

Interface SimpleQueue

Type Parameters:

T - the value type to offer and poll, not null

All Known Subinterfaces:

QueueDisposable, QueueFuseable, QueueSubscription, SimplePlainQueue

All Known Implementing Classes:

SpscArrayQueue, SpscLinkedArrayQueue

public interface SimpleQueue

A simplified interface for offering, polling and clearing a queue.

This interface does not define most of the Collection or Queue methods as the intended usage of SimpleQueue does not require support for iteration or introspection.

Since:

3.1.1

Method Summary

Modifier and Type	Method and Description
void	clear() Removes all enqueued items from this queue.
boolean	isEmpty() Returns true if the queue is empty.
boolean	offer(T value) Atomically enqueue a single value.
boolean	offer(T v1, T v2) Atomically enqueue two values.
T	poll() Tries to dequeue a value (non-null) or returns null if the queue is empty.

Method Detail

offer

boolean offer(@NonNull
              T value)

Atomically enqueue a single value.

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

boolean offer(@NonNull
              T v1,
              @NonNull
              T v2)

Atomically enqueue two values.

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

@Nullable
T poll()
          throws Throwable

Tries to dequeue a value (non-null) or returns null if the queue is empty.

If the producer uses 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.

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

boolean isEmpty()

Returns true if the queue is empty.

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

Returns:

true if the queue is empty

clear

void clear()

Removes all enqueued items from this queue.