Package com.db4o.foundation

Class BlockingQueue<T>

java.lang.Object

com.db4o.foundation.BlockingQueue<T>

All Implemented Interfaces:

BlockingQueue4<T>, Queue4<T>

Direct Known Subclasses:

PausableBlockingQueue

public class BlockingQueue<T>
extends java.lang.Object
implements BlockingQueue4<T>

Field Summary

Fields

Modifier and Type	Field	Description
protected Lock4	_lock
protected NonblockingQueue<T>	_queue
protected boolean	_stopped

Constructor Summary

Constructors

Constructor	Description
BlockingQueue()

Method Summary

Modifier and Type	Method	Description
void	add(T obj)
int	drainTo(Collection4<T> target)	Removes all the available elements in the queue to the colletion passed as argument.
boolean	hasNext()
Iterator4<T>	iterator()
T	next()
T	next(long timeout)	Returns the next queued item or waits for it to be available for the maximum of timeout miliseconds.
T	nextMatching(Predicate4<T> condition)	Returns the next object in the queue that matches the specified condition.
void	stop()
protected void	unsafeWaitForNext()
protected boolean	unsafeWaitForNext(long timeout)
void	waitForNext()
boolean	waitForNext(long timeout)

Methods inherited from class java.lang.Object

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

Field Detail

_queue

protected NonblockingQueue<T> _queue

_lock

protected Lock4 _lock

_stopped

protected boolean _stopped

Constructor Detail

BlockingQueue

public BlockingQueue()

Method Detail

add

public void add(T obj)

Specified by:

add in interface Queue4<T>

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Queue4<T>

iterator

public Iterator4<T> iterator()

Specified by:

iterator in interface Queue4<T>

next

public T next(long timeout)
       throws BlockingQueueStoppedException

Description copied from interface: BlockingQueue4

Returns the next queued item or waits for it to be available for the maximum of timeout miliseconds.

Specified by:

next in interface BlockingQueue4<T>

Parameters:

timeout - maximum time to wait for the next avilable item in miliseconds

Returns:

the next item or null if timeout is reached

Throws:

BlockingQueueStoppedException - if the BlockingQueue4.stop() is called.

drainTo

public int drainTo(Collection4<T> target)

Description copied from interface: BlockingQueue4

Removes all the available elements in the queue to the colletion passed as argument.

It will block until at least one element is available.

Specified by:

drainTo in interface BlockingQueue4<T>

Returns:

the number of elements added to the list.

waitForNext

public boolean waitForNext(long timeout)
                    throws BlockingQueueStoppedException

Throws:

BlockingQueueStoppedException

next

public T next()
       throws BlockingQueueStoppedException

Specified by:

next in interface Queue4<T>

Throws:

BlockingQueueStoppedException

stop

public void stop()

Specified by:

stop in interface BlockingQueue4<T>

nextMatching

public T nextMatching(Predicate4<T> condition)

Description copied from interface: Queue4

Returns the next object in the queue that matches the specified condition. The operation is always NON-BLOCKING.

Specified by:

nextMatching in interface Queue4<T>

Parameters:

condition - the object must satisfy to be returned

Returns:

the object satisfying the condition or null if none does

waitForNext

public void waitForNext()
                 throws BlockingQueueStoppedException

Throws:

BlockingQueueStoppedException

unsafeWaitForNext

protected void unsafeWaitForNext()
                          throws BlockingQueueStoppedException

Throws:

BlockingQueueStoppedException

unsafeWaitForNext

protected boolean unsafeWaitForNext(long timeout)
                             throws BlockingQueueStoppedException

Throws:

BlockingQueueStoppedException