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/*
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* Copyright 1997-2003 Sun Microsystems, Inc. All Rights Reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Sun designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Sun in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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* CA 95054 USA or visit www.sun.com if you need additional information or
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* have any questions.
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*/
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package java.lang.ref;
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/**
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* Weak reference objects, which do not prevent their referents from being
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* made finalizable, finalized, and then reclaimed. Weak references are most
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* often used to implement canonicalizing mappings.
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*
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* <p> Suppose that the garbage collector determines at a certain point in time
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* that an object is <a href="package-summary.html#reachability">weakly
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* reachable</a>. At that time it will atomically clear all weak references to
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* that object and all weak references to any other weakly-reachable objects
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* from which that object is reachable through a chain of strong and soft
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* references. At the same time it will declare all of the formerly
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* weakly-reachable objects to be finalizable. At the same time or at some
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* later time it will enqueue those newly-cleared weak references that are
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* registered with reference queues.
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*
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* @author Mark Reinhold
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* @since 1.2
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*/
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public class WeakReference<T> extends Reference<T> {
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/**
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* Creates a new weak reference that refers to the given object. The new
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* reference is not registered with any queue.
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*
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* @param referent object the new weak reference will refer to
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*/
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public WeakReference(T referent) {
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super(referent);
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}
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/**
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* Creates a new weak reference that refers to the given object and is
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* registered with the given queue.
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*
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* @param referent object the new weak reference will refer to
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* @param q the queue with which the reference is to be registered,
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* or <tt>null</tt> if registration is not required
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*/
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public WeakReference(T referent, ReferenceQueue<? super T> q) {
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super(referent, q);
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}
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}
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