rt/emul/compact/src/main/java/java/lang/ref/WeakReference.java
author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
Tue, 26 Feb 2013 16:54:16 +0100
changeset 772 d382dacfd73f
parent 601 emul/compact/src/main/java/java/lang/ref/WeakReference.java@5198affdb915
permissions -rw-r--r--
Moving modules around so the runtime is under one master pom and can be built without building other modules that are in the repository
     1 /*
     2  * Copyright (c) 1997, 2003, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.  Oracle designates this
     8  * particular file as subject to the "Classpath" exception as provided
     9  * by Oracle in the LICENSE file that accompanied this code.
    10  *
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    14  * version 2 for more details (a copy is included in the LICENSE file that
    15  * accompanied this code).
    16  *
    17  * You should have received a copy of the GNU General Public License version
    18  * 2 along with this work; if not, write to the Free Software Foundation,
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    20  *
    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    22  * or visit www.oracle.com if you need additional information or have any
    23  * questions.
    24  */
    25 
    26 package java.lang.ref;
    27 
    28 
    29 /**
    30  * Weak reference objects, which do not prevent their referents from being
    31  * made finalizable, finalized, and then reclaimed.  Weak references are most
    32  * often used to implement canonicalizing mappings.
    33  *
    34  * <p> Suppose that the garbage collector determines at a certain point in time
    35  * that an object is <a href="package-summary.html#reachability">weakly
    36  * reachable</a>.  At that time it will atomically clear all weak references to
    37  * that object and all weak references to any other weakly-reachable objects
    38  * from which that object is reachable through a chain of strong and soft
    39  * references.  At the same time it will declare all of the formerly
    40  * weakly-reachable objects to be finalizable.  At the same time or at some
    41  * later time it will enqueue those newly-cleared weak references that are
    42  * registered with reference queues.
    43  *
    44  * @author   Mark Reinhold
    45  * @since    1.2
    46  */
    47 
    48 public class WeakReference<T> extends Reference<T> {
    49 
    50     /**
    51      * Creates a new weak reference that refers to the given object.  The new
    52      * reference is not registered with any queue.
    53      *
    54      * @param referent object the new weak reference will refer to
    55      */
    56     public WeakReference(T referent) {
    57         super(referent);
    58     }
    59 
    60     /**
    61      * Creates a new weak reference that refers to the given object and is
    62      * registered with the given queue.
    63      *
    64      * @param referent object the new weak reference will refer to
    65      * @param q the queue with which the reference is to be registered,
    66      *          or <tt>null</tt> if registration is not required
    67      */
    68     public WeakReference(T referent, ReferenceQueue<? super T> q) {
    69         super(referent, q);
    70     }
    71 
    72 }