Mercurial > hg > blitz_condensed
annotate src/EDU/oswego/cs/dl/util/concurrent/NullSync.java @ 34:6f68e94c1fb8 default tip
Add CondensedStats monitoring utility, equivalent to vmstat
author | Dominic Cleal <dominic-cleal@cdo2.com> |
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date | Thu, 05 Aug 2010 11:07:25 +0100 |
parents | 3dc0c5604566 |
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Initial checkin of blitz 2.0 fcs - no installer yet.
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1 /* |
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2 File: NullSync.java |
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3 |
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4 Originally written by Doug Lea and released into the public domain. |
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5 This may be used for any purposes whatsoever without acknowledgment. |
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6 Thanks for the assistance and support of Sun Microsystems Labs, |
3dc0c5604566
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7 and everyone contributing, testing, and using this code. |
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8 |
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9 History: |
3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
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10 Date Who What |
3dc0c5604566
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11 1Aug1998 dl Create public version |
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12 */ |
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13 |
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14 package EDU.oswego.cs.dl.util.concurrent; |
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15 |
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16 /** |
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17 * A No-Op implementation of Sync. Acquire never blocks, |
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18 * Attempt always succeeds, Release has no effect. |
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19 * However, acquire and release do detect interruption |
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20 * and throw InterruptedException. Also, the methods |
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21 * are synchronized, so preserve memory barrier properties |
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22 * of Syncs. |
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23 * <p> |
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24 * NullSyncs can be useful in optimizing classes when |
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25 * it is found that locking is not strictly necesssary. |
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26 * |
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27 * <p>[<a href="http://gee.cs.oswego.edu/dl/classes/EDU/oswego/cs/dl/util/concurrent/intro.html"> Introduction to this package. </a>] |
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28 **/ |
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29 |
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31 public class NullSync implements Sync { |
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32 |
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33 public synchronized void acquire() throws InterruptedException { |
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34 if (Thread.interrupted()) throw new InterruptedException(); |
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35 } |
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36 |
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37 public synchronized boolean attempt(long msecs) throws InterruptedException { |
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38 if (Thread.interrupted()) throw new InterruptedException(); |
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Initial checkin of blitz 2.0 fcs - no installer yet.
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39 return true; |
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40 } |
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41 |
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42 public synchronized void release() {} |
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Initial checkin of blitz 2.0 fcs - no installer yet.
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Dan Creswell <dan.creswell@gmail.com>
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Initial checkin of blitz 2.0 fcs - no installer yet.
Dan Creswell <dan.creswell@gmail.com>
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45 } |
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