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comparison src/EDU/oswego/cs/dl/util/concurrent/NullSync.java @ 0:3dc0c5604566

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Initial checkin of blitz 2.0 fcs - no installer yet.
author Dan Creswell <dan.creswell@gmail.com>
date Sat, 21 Mar 2009 11:00:06 +0000
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1 /*
2 File: NullSync.java
3
4 Originally written by Doug Lea and released into the public domain.
5 This may be used for any purposes whatsoever without acknowledgment.
6 Thanks for the assistance and support of Sun Microsystems Labs,
7 and everyone contributing, testing, and using this code.
8
9 History:
10 Date Who What
11 1Aug1998 dl Create public version
12 */
13
14 package EDU.oswego.cs.dl.util.concurrent;
15
16 /**
17 * A No-Op implementation of Sync. Acquire never blocks,
18 * Attempt always succeeds, Release has no effect.
19 * However, acquire and release do detect interruption
20 * and throw InterruptedException. Also, the methods
21 * are synchronized, so preserve memory barrier properties
22 * of Syncs.
23 * <p>
24 * NullSyncs can be useful in optimizing classes when
25 * it is found that locking is not strictly necesssary.
26 *
27 * <p>[<a href="http://gee.cs.oswego.edu/dl/classes/EDU/oswego/cs/dl/util/concurrent/intro.html"> Introduction to this package. </a>]
28 **/
29
30
31 public class NullSync implements Sync {
32
33 public synchronized void acquire() throws InterruptedException {
34 if (Thread.interrupted()) throw new InterruptedException();
35 }
36
37 public synchronized boolean attempt(long msecs) throws InterruptedException {
38 if (Thread.interrupted()) throw new InterruptedException();
39 return true;
40 }
41
42 public synchronized void release() {}
43
44
45 }
46
47