org.ros.concurrent

Class CircularBlockingDeque<T>

java.lang.Object

org.ros.concurrent.CircularBlockingDeque<T>

All Implemented Interfaces:

java.lang.Iterable<T>

public class CircularBlockingDeque<T>
extends java.lang.Object
implements java.lang.Iterable<T>

A deque that removes head or tail elements when the number of elements exceeds the limit and blocks on takeFirst() and takeLast() when there are no elements available.

Constructor Summary

Constructors

Constructor and Description
CircularBlockingDeque(int capacity)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	addFirst(T entry) Adds the specified entry to the tail of the queue, overwriting older entries if necessary.
boolean	addLast(T entry) Adds the specified entry to the tail of the queue, overwriting older entries if necessary.
boolean	isEmpty()
java.util.Iterator<T>	iterator() Returns an iterator over the queue.
T	peekFirst() Retrieves, but does not remove, the head of this queue, returning null if this queue is empty.
T	peekLast() Retrieves, but does not remove, the tail of this queue, returning null if this queue is empty.
T	takeFirst() Retrieves the head of the queue, blocking if necessary until an entry is available.
T	takeLast() Retrieves the tail of the queue, blocking if necessary until an entry is available.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CircularBlockingDeque

public CircularBlockingDeque(int capacity)

Parameters:

capacity - the maximum number of elements allowed in the queue

Method Detail

addLast

public boolean addLast(T entry)

Adds the specified entry to the tail of the queue, overwriting older entries if necessary.

Parameters:

entry - the entry to add

Returns:

true

addFirst

public boolean addFirst(T entry)

Adds the specified entry to the tail of the queue, overwriting older entries if necessary.

Parameters:

entry - the entry to add

Returns:

true

takeFirst

public T takeFirst()
            throws java.lang.InterruptedException

Retrieves the head of the queue, blocking if necessary until an entry is available.

Returns:

the head of the queue

Throws:

java.lang.InterruptedException

peekFirst

public T peekFirst()

Retrieves, but does not remove, the head of this queue, returning null if this queue is empty.

Returns:

the head of this queue, or null if this queue is empty

takeLast

public T takeLast()
           throws java.lang.InterruptedException

Retrieves the tail of the queue, blocking if necessary until an entry is available.

Returns:

the tail of the queue

Throws:

java.lang.InterruptedException

peekLast

public T peekLast()

Retrieves, but does not remove, the tail of this queue, returning null if this queue is empty.

Returns:

the tail of this queue, or null if this queue is empty

isEmpty

public boolean isEmpty()

iterator

public java.util.Iterator<T> iterator()

Returns an iterator over the queue.

Note that this is not thread-safe and that Iterator.remove() is unsupported.

Specified by:

iterator in interface java.lang.Iterable<T>

See Also:

Iterable.iterator()