/* |
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* Copyright (c) 1997, 2003, Oracle and/or its affiliates. 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. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* 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 {@code null} 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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} |