LinkedBlockingQueue

public class LinkedBlockingQueue extends AbstractQueue<E>
implements BlockingQueue<E> Serializable

An optionally-bounded {@linkplain BlockingQueue blocking queue} based on linked nodes. This queue orders elements FIFO (first-in-first-out). The head of the queue is that element that has been on the queue the longest time. The tail of the queue is that element that has been on the queue the shortest time. New elements are inserted at the tail of the queue, and the queue retrieval operations obtain elements at the head of the queue. Linked queues typically have higher throughput than array-based queues but less predictable performance in most concurrent applications.

The optional capacity bound constructor argument serves as a way to prevent excessive queue expansion. The capacity, if unspecified, is equal to MAX_VALUE. Linked nodes are dynamically created upon each insertion unless this would bring the queue above capacity.

This class and its iterator implement all of the optional methods of the Collection and Iterator interfaces.

Public Constructor Summary

LinkedBlockingQueue()
Creates a LinkedBlockingQueue with a capacity of MAX_VALUE.
LinkedBlockingQueue(int capacity)
Creates a LinkedBlockingQueue with the given (fixed) capacity.
LinkedBlockingQueue(Collection<? extends E> c)
Creates a LinkedBlockingQueue with a capacity of MAX_VALUE, initially containing the elements of the given collection, added in traversal order of the collection's iterator.

Public Method Summary

void
clear()
Atomically removes all of the elements from this queue.
boolean
contains(Object o)
Returns true if this queue contains the specified element.
int
drainTo(Collection<? super E> c, int maxElements)
Removes at most the given number of available elements from this queue and adds them to the given collection.
int
drainTo(Collection<? super E> c)
Removes all available elements from this queue and adds them to the given collection.
Iterator<E>
iterator()
Returns an iterator over the elements in this queue in proper sequence.
boolean
offer(E e)
Inserts the specified element at the tail of this queue if it is possible to do so immediately without exceeding the queue's capacity, returning true upon success and false if this queue is full.
boolean
offer(E e, long timeout, TimeUnit unit)
Inserts the specified element at the tail of this queue, waiting if necessary up to the specified wait time for space to become available.
E
peek()
Retrieves, but does not remove, the head of this queue, or returns null if this queue is empty.
E
poll(long timeout, TimeUnit unit)
Retrieves and removes the head of this queue, waiting up to the specified wait time if necessary for an element to become available.
E
poll()
Retrieves and removes the head of this queue, or returns null if this queue is empty.
void
put(E e)
Inserts the specified element at the tail of this queue, waiting if necessary for space to become available.
int
remainingCapacity()
Returns the number of additional elements that this queue can ideally (in the absence of memory or resource constraints) accept without blocking.
boolean
remove(Object o)
Removes a single instance of the specified element from this queue, if it is present.
int
size()
Returns the number of elements in this queue.
Spliterator<E>
spliterator()
Returns a Spliterator over the elements in this queue.
E
take()
Retrieves and removes the head of this queue, waiting if necessary until an element becomes available.
<T> T[]
toArray(T[] a)
Returns an array containing all of the elements in this queue, in proper sequence; the runtime type of the returned array is that of the specified array.
Object[]
toArray()
Returns an array containing all of the elements in this queue, in proper sequence.
String
toString()
Returns a string representation of this collection.

Protected Method Summary

void
finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.

Inherited Method Summary