diff -r 4252bfc396fc -r d382dacfd73f emul/compact/src/main/java/java/lang/ref/SoftReference.java --- a/emul/compact/src/main/java/java/lang/ref/SoftReference.java Tue Feb 26 14:55:55 2013 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,118 +0,0 @@ -/* - * Copyright (c) 1997, 2003, Oracle and/or its affiliates. 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. Oracle designates this - * particular file as subject to the "Classpath" exception as provided - * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - */ - -package java.lang.ref; - - -/** - * Soft reference objects, which are cleared at the discretion of the garbage - * collector in response to memory demand. Soft references are most often used - * to implement memory-sensitive caches. - * - *
Suppose that the garbage collector determines at a certain point in time - * that an object is softly - * reachable. At that time it may choose to clear atomically all soft - * references to that object and all soft references to any other - * softly-reachable objects from which that object is reachable through a chain - * of strong references. At the same time or at some later time it will - * enqueue those newly-cleared soft references that are registered with - * reference queues. - * - *
All soft references to softly-reachable objects are guaranteed to have
- * been cleared before the virtual machine throws an
- * OutOfMemoryError
. Otherwise no constraints are placed upon the
- * time at which a soft reference will be cleared or the order in which a set
- * of such references to different objects will be cleared. Virtual machine
- * implementations are, however, encouraged to bias against clearing
- * recently-created or recently-used soft references.
- *
- *
Direct instances of this class may be used to implement simple caches;
- * this class or derived subclasses may also be used in larger data structures
- * to implement more sophisticated caches. As long as the referent of a soft
- * reference is strongly reachable, that is, is actually in use, the soft
- * reference will not be cleared. Thus a sophisticated cache can, for example,
- * prevent its most recently used entries from being discarded by keeping
- * strong referents to those entries, leaving the remaining entries to be
- * discarded at the discretion of the garbage collector.
- *
- * @author Mark Reinhold
- * @since 1.2
- */
-
-public class SoftReferencenull
.
- *
- * @return The object to which this reference refers, or
- * null
if this reference object has been cleared
- */
- public T get() {
- T o = super.get();
- if (o != null && this.timestamp != clock)
- this.timestamp = clock;
- return o;
- }
-
-}