/* * Copyright 2003 Sun Microsystems, Inc. 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. Sun designates this * particular file as subject to the "Classpath" exception as provided * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. */ package com.sun.jndi.ldap.pool; import java.lang.ref.WeakReference; import java.lang.ref.ReferenceQueue; /* * This class defines a WeakReference to the ConnectionRef (the referent). * * The ConnectionRef enables to break the reference * cycle between Connection, LdapClient, Connections and ConnectionDesc, * shown in the figure below. * * -------> Connections -----> ConnectionDesc * | ^ | * | | | * | | | * ConnectionsRef LdapClient <------------ * ^ | ^ * : | | * : v | * ConnectionsWeakRef Connection * * The ConnectionsRef is for cleaning up the resources held by the * Connection thread by making them available to the GC. The pool * uses ConnectionRef to hold the pooled resources. * * This class in turn holds a WeakReference with a ReferenceQueue to the * ConnectionRef to track when the ConnectionRef becomes ready * for getting GC'ed. It extends from WeakReference in order to hold a * reference to Connections used for closing (which in turn terminates * the Connection thread) it by monitoring the ReferenceQueue. */ class ConnectionsWeakRef extends WeakReference { private final Connections conns; ConnectionsWeakRef (ConnectionsRef connsRef, ReferenceQueue queue) { super(connsRef, queue); this.conns = connsRef.getConnections(); } Connections getConnections() { return conns; } }