/*
* The contents of this file is dual-licensed under 2
* alternative Open Source/Free licenses: LGPL 2.1 or later and
* Apache License 2.0. (starting with JNA version 4.0.0).
*
* You can freely decide which license you want to apply to
* the project.
*
* You may obtain a copy of the LGPL License at:
*
* http://www.gnu.org/licenses/licenses.html
*
* A copy is also included in the downloadable source code package
* containing JNA, in file "LGPL2.1".
*
* You may obtain a copy of the Apache License at:
*
* http://www.apache.org/licenses/
*
* A copy is also included in the downloadable source code package
* containing JNA, in file "AL2.0".
*/
package com.sun.jna;
import java.lang.ref.
Reference;
import java.lang.ref.
ReferenceQueue;
import java.lang.ref.
WeakReference;
import java.util.
IdentityHashMap;
/**
* Helper to hold a memory object based on the lifetime of another object.
*
* The intended use is to assoziate a ByteBuffer with its backing Memory object.
*
* The ByteBuffer is held by a WeakReference and a ReferenceQueue is used to
* track GC of the ByteBuffer.
*
* The references to the memory objects are released on access of WeakMemoryHolder.
*/
public class
WeakMemoryHolder {
ReferenceQueue<
Object>
referenceQueue = new
ReferenceQueue<
Object>();
IdentityHashMap<
Reference<
Object>,
Memory>
backingMap = new
IdentityHashMap<
Reference<
Object>,
Memory>();
public synchronized void
put(
Object o,
Memory m) {
clean();
Reference<
Object>
reference = new
WeakReference<
Object>(
o,
referenceQueue);
backingMap.
put(
reference,
m);
}
public synchronized void
clean() {
for(
Reference ref =
referenceQueue.
poll();
ref != null;
ref =
referenceQueue.
poll()) {
backingMap.
remove(
ref);
}
}
}