java.lang.ref

Class ReferenceQueue<T>

java.lang.Object

java.lang.ref.ReferenceQueue<T>

public class ReferenceQueue<T>
extends Object

The ReferenceQueue is the container on which reference objects are enqueued when the garbage collector detects the reachability type specified for the referent.

Since:

1.2

Field Summary

Fields

Modifier and Type	Field and Description
static Reference<?>	unenqueued

Constructor Summary

Constructors

Constructor and Description
ReferenceQueue() Constructs a new instance of this class.

Method Summary

Modifier and Type	Method and Description
Reference<? extends T>	poll() Returns the next available reference from the queue, removing it in the process.
Reference<? extends T>	remove() Returns the next available reference from the queue, removing it in the process.
Reference<? extends T>	remove(long timeoutMillis) Returns the next available reference from the queue, removing it in the process.

Methods inherited from class java.lang.Object

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

Field Detail

unenqueued

public static Reference<?> unenqueued

Constructor Detail

ReferenceQueue

public ReferenceQueue()

Constructs a new instance of this class.

Method Detail

poll

public Reference<? extends T> poll()

Returns the next available reference from the queue, removing it in the process. Does not wait for a reference to become available.

Returns:

the next available reference, or null if no reference is immediately available

remove

public Reference<? extends T> remove()
                              throws InterruptedException

Returns the next available reference from the queue, removing it in the process. Waits indefinitely for a reference to become available.

Throws:

InterruptedException - if the blocking call was interrupted

remove

public Reference<? extends T> remove(long timeoutMillis)
                              throws InterruptedException

Returns the next available reference from the queue, removing it in the process. Waits for a reference to become available or the given timeout period to elapse, whichever happens first.

Parameters:

timeoutMillis - maximum time to spend waiting for a reference object to become available. A value of 0 results in the method waiting indefinitely.

Returns:

the next available reference, or null if no reference becomes available within the timeout period

Throws:

IllegalArgumentException - if timeoutMillis < 0.

InterruptedException - if the blocking call was interrupted