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This is a backport of OpenJFX 8 to run on Java 7.
The newest version!
/*
* Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.prism.impl;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.PhantomReference;
import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.util.Hashtable;
import java.util.LinkedList;
/**
* This class is used for registering and disposing the native
* data associated with Java objects.
*
* The object can register itself by calling one of the addRecord
* methods and providing either the pointer to the native disposal
* method or a descendant of the Disposer.Record interface with overridden
* dispose() method.
*
* When the object becomes unreachable, the dispose() method
* of the associated Disposer.Record object will be called.
*/
public class Disposer {
private static Disposer disposerInstance;
private static final int WEAK = 0;
private static final int PHANTOM = 1;
private static final int SOFT = 2;
private static int refType = PHANTOM;
static {
String type = PrismSettings.refType;
if (type != null) {
if (type.equals("weak")) {
refType = WEAK;
if (PrismSettings.verbose) System.err.println("Using WEAK refs");
} else if (type.equals("soft")) {
refType = SOFT;
if (PrismSettings.verbose) System.err.println("Using SOFT refs");
} else {
refType = PHANTOM;
if (PrismSettings.verbose) System.err.println("Using PHANTOM refs");
}
}
disposerInstance = new Disposer();
}
private final ReferenceQueue queue = new ReferenceQueue();
private final Hashtable records = new Hashtable();
private final LinkedList disposalQueue = new LinkedList();
/**
* Private constructor to prevent outside instantiation.
*/
private Disposer() {
}
// /**
// * Registers the object and the native data for later disposal.
// * @param target Object to be registered
// * @param disposeMethod pointer to the native disposal method
// * @param pData pointer to the data to be passed to the
// * native disposal method
// */
// public static void addRecord(Object target,
// long disposeMethod, long pData)
// {
// disposerInstance.add(target,
// new DefaultDisposerRecord(disposeMethod, pData));
// }
/**
* Registers the target object and the native data for later disposal when
* the target is unreachable.
* .
* @param target Object to be registered
* @param rec the associated DisposerRecord object
* @see DisposerRecord
*/
public static void addRecord(Object target, Disposer.Record rec) {
disposerInstance.add(target, rec);
}
/**
* Add the object to the disposal queue. The object will be disposed
* the next time cleanup is called.
*
* @param rec the DisposerRecord object to be disposed
*/
public static void disposeRecord(Disposer.Record rec) {
disposerInstance.addToDisposalQueue(rec);
}
/**
* Disposes all unreachable objects and all objects in the disposal queue.
* It first polls the reference queue, calling the dispose method of each
* unreachable object. It then iterates the list of objects in the
* disposal queue, calling the dispose method of each object.
*
* NOTE: This method must only be called from the Render Thread (the
* thread on which the resources were created).
*/
public static void cleanUp() {
disposerInstance.disposeUnreachables();
disposerInstance.processDisposalQueue();
}
/**
* Performs the actual registration of the target object to be disposed.
* @param target Object to be registered, or if target is an instance
* of DisposerTarget, its associated disposer referent
* will be the Object that is registered
* @param rec the associated DisposerRecord object
* @see DisposerRecord
*/
synchronized private void add(Object target, Disposer.Record rec) {
if (target instanceof Disposer.Target) {
target = ((Disposer.Target)target).getDisposerReferent();
}
Reference ref;
if (refType == PHANTOM) {
ref = new PhantomReference(target, queue);
} else if (refType == SOFT) {
ref = new SoftReference(target, queue);
} else {
ref = new WeakReference(target, queue);
}
records.put(ref, rec);
}
synchronized private void addToDisposalQueue(Disposer.Record rec) {
disposalQueue.add(rec);
}
/**
* Polls the reference queue to see if there are any unreachable objects
* to be disposed. If there is work to be done, this method disposes all
* unreachable objects in the queue, otherwise it returns immediately.
*/
synchronized private void disposeUnreachables() {
Object obj;
while ((obj = queue.poll()) != null) {
try {
((Reference)obj).clear();
Disposer.Record rec = (Disposer.Record)records.remove(obj);
rec.dispose();
obj = null;
rec = null;
} catch (Exception e) {
System.out.println("Exception while removing reference: " + e);
e.printStackTrace();
}
}
}
synchronized private void processDisposalQueue() {
// disposalQueue is always empty in the case of Windows using the d3d pipe.
while (!disposalQueue.isEmpty()) {
disposalQueue.remove().dispose();
}
}
/**
* This interface is used to hold the resource to be disposed.
*/
public static interface Record {
public void dispose();
}
/**
* This is an interface which should be implemented by
* the classes which use Disposer.
*/
public static interface Target {
/**
* Returns an object which will be
* used as the referent in the ReferenceQueue.
*/
public Object getDisposerReferent();
}
}