hudson.remoting.ExportedClassLoaderTable Maven / Gradle / Ivy
/*
* The MIT License
*
* Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package hudson.remoting;
import java.lang.ref.WeakReference;
import java.util.HashMap;
import java.util.Map;
import java.util.WeakHashMap;
/**
* Manages unique ID for classloaders.
*
* @author Kohsuke Kawaguchi
*/
final class ExportedClassLoaderTable {
private final Map> table = new HashMap>();
private final WeakHashMap reverse = new WeakHashMap();
// id==0 is reserved for bootstrap classloader
private int iota = 1;
public synchronized int intern(ClassLoader cl) {
if(cl==null) return 0; // bootstrap classloader
Integer id = reverse.get(cl);
if(id==null) {
id = iota++;
table.put(id,new WeakReference(cl));
reverse.put(cl,id);
}
return id;
}
public synchronized ClassLoader get(int id) {
WeakReference ref = table.get(id);
if(ref==null) return null;
return ref.get();
}
}