wyvern.common.util
Class VectorQueue

java.lang.Object
  wyvern.common.util.VectorQueue

public class VectorQueue

extends java.lang.Object

This class implements a standard thread-safe queue. Calling dequeue() will block the caller until something is placed in the queue by another thread. It's 1.1-compatible, but the dequeue() operation is O(n), since Vector.removeElementAt(0) has to shuffle all the remaining elements to the left.

Version:

1.0, Mar 28, 1999

Author:

Steve Yegge

Constructor Summary

VectorQueue()
Constructs a new VectorQueue

Method Summary

java.lang.Object	dequeue() Removes an object from the front of the queue.
void	enqueue(java.lang.Object obj) Puts an object at the rear of the queue.
java.util.Vector	getItems() Returns the list of items in the queue.
boolean	isEmpty() Returns true if the queue contains no items.
boolean	remove(java.lang.Object obj) Removes an object from the queue.
int	size() Returns the number of items currently in the queue.

Methods inherited from class java.lang.Object

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

Constructor Detail

VectorQueue

public VectorQueue()

Constructs a new VectorQueue

Method Detail

enqueue

public void enqueue(java.lang.Object obj)

Puts an object at the rear of the queue.

Parameters:

obj - any object to enqueue

dequeue

public java.lang.Object dequeue()

Removes an object from the front of the queue.

Returns:

the object at the front. Blocks until an object is available.

isEmpty

public boolean isEmpty()

Returns true if the queue contains no items.

Returns:

true if the queue is empty

size

public int size()

Returns the number of items currently in the queue.

Returns:

the current queue length

getItems

public java.util.Vector getItems()

Returns the list of items in the queue. This is the *actual* list, not a copy of it, so make sure you synchronize on the Queue object (not the list this method returns) to prevent synchronization problems.

remove

public boolean remove(java.lang.Object obj)

Removes an object from the queue.

Parameters:

obj - the object to remove

Returns:

true if the object was in the queue