Howdy, I'll try to test it on Solaris 8 and Win2K tomorrow, at least with JDK 1.4.1.
Yoav Shapira Millennium ChemInformatics >-----Original Message----- >From: Ceki Gülcü [mailto:[EMAIL PROTECTED] >Sent: Monday, June 02, 2003 3:53 PM >To: Log4J Developers List >Subject: RE: ReaderWriterLock, faster implementation? > > >The code I have written is similar to Doug Lea's >ReaderWriterLock. Actually, my code was inspired from Allen Holub's >Reader/writer locks article (See JavaWorld April 1999) which was >itself inspired by Doug Lea's code. > >Anyway, the ReaderWriterLock as it exists in log4j cvs is considerably >simpler but it also offers much less functionality. (No free luch >here.) You can test it by calling 'ant ReaderWriterLock' from the >LOG4J_HOME/tests/ directory. (You have to have jakarta-oro and junit in >your classpath and check out the latest from CVS.) > >The test takes about half an hour using a fast machine. I've tested it >with JDK 1.3.1 and JDK 1.4.1 under Windows XP. Tests with other OSs >and JDKs are highly encouraged and would be much appreciated. > >As for reentrance, as far as I can tell, we do not need it. > >At 08:38 AM 5/27/2003 -0500, Ebersole, Steven wrote: >>I wrote a reader/writer impl, but the target was caching, not a file. >>However, the basic implementation was based on Doug Lea's excellent >>concurrency package using his ReentrantWriterPreferenceReadWriteLock >class. >>The purpose of this class is what you describe, waiting writers are given >>preference over waiting readers. The nice thing about his package is that >>all the Object wait/notify stuff is hidden behind the scenes and simply >>presented as a Lock which clients acquire() and release(). >> >>Not sure how you would feel about use of his package, but if you are >>interested I can whip up some code to convert this cache stuff I have now. >> >> >> |-----Original Message----- >> |From: Ceki Gülcü [mailto:[EMAIL PROTECTED] >> |Sent: Saturday, May 24, 2003 4:11 PM >> |To: Log4J Developers List >> |Subject: ReaderWriterLock, faster implementation? >> | >> | >> | >> |I have just committed a remarkably simple implementation of a >> |ReaderWriterLock. A ReaderWriterLock allows simultaneous read >> |operations but only one write operation. Waiting writers >> |have priority >> |over waiting readers. >> | >> |The code seems to be working but will be massively tested >> |just to make >> |sure. >> | >> |If you know of a faster implementation do not hesitate to show the >> |way. In particular, I'd like to be able to avoid the notifyAll call >> |and replace it with notify(). >> | >> |At 09:04 PM 5/24/2003 +0000, you wrote: >> |>ceki 2003/05/24 14:04:00 >> |> >> |> Modified: tests build.xml >> |> Added: src/java/org/apache/log4j/helpers >> |ReaderWriterLock.java >> |> tests/src/java/org/apache/log4j/helpers >> |> ReaderWriterLockTestCase.java >> |> Log: >> |> >> |> A remarkably simple implementation of a >> |ReaderWriterLock with priority >> |> to writers. >> |> >> |> Revision Changes Path >> |> 1.1 >> |> >> |jakarta-log4j/src/java/org/apache/log4j/helpers/ReaderWrite >> |rLock.java >> |> >> |> Index: ReaderWriterLock.java >> |> >> |=================================================================== >> |> /* >> |> * >> |> >> |=========================================================== >> |================= >> |> * The Apache Software License, Version 1.1 >> |> * >> |> >> |=========================================================== >> |================= >> |> * >> |> * Copyright (C) 1999 The Apache Software >> |Foundation. All rights >> |> reserved. >> |> * >> |> * Redistribution and use in source and binary forms, >> |with or without >> |> modifica- >> |> * tion, are permitted provided that the following >> |conditions are met: >> |> * >> |> * 1. Redistributions of source code must retain the above >> |> copyright notice, >> |> * this list of conditions and the following disclaimer. >> |> * >> |> * 2. Redistributions in binary form must reproduce >> |the above copyright >> |> notice, >> |> * this list of conditions and the following >> |disclaimer in the >> |> documentation >> |> * and/or other materials provided with the distribution. >> |> * >> |> * 3. The end-user documentation included with the >> |redistribution, if >> |> any, must >> |> * include the following acknowledgment: "This product >> |> includes software >> |> * developed by the Apache Software >> |> Foundation (http://www.apache.org/)." >> |> * Alternately, this acknowledgment may appear in >> |the software >> |> itself, if >> |> * and wherever such third-party acknowledgments >> |normally appear. >> |> * >> |> * 4. The names "log4j" and "Apache Software >> |Foundation" must not be >> |> used to >> |> * endorse or promote products derived from this >> | software >> |> without prior >> |> * written permission. For written permission, >> |please contact >> |> * [EMAIL PROTECTED] >> |> * >> |> * 5. Products derived from this software may not be >> |called "Apache", >> |> nor may >> |> * "Apache" appear in their name, without prior written >> |> permission of the >> |> * Apache Software Foundation. >> |> * >> |> * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY >> |EXPRESSED OR IMPLIED >> |> WARRANTIES, >> |> * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF >> |> MERCHANTABILITY AND >> |> * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. >> | IN NO EVENT >> |> SHALL THE >> |> * APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS >> |BE LIABLE FOR ANY >> |> DIRECT, >> |> * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR >> |CONSEQUENTIAL DAMAGES >> |> (INCLU- >> |> * DING, BUT NOT LIMITED TO, PROCUREMENT OF >> |SUBSTITUTE GOODS OR >> |> SERVICES; LOSS >> |> * OF USE, DATA, OR PROFITS; OR BUSINESS >> |INTERRUPTION) HOWEVER >> |> CAUSED AND ON >> |> * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT >> |> LIABILITY, OR TORT >> |> * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN >> |ANY WAY OUT OF >> |> THE USE OF >> |> * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY >> |OF SUCH DAMAGE. >> |> * >> |> * This software consists of voluntary contributions >> |made by many >> |> individuals >> |> * on behalf of the Apache Software Foundation. For >> |> more information on the >> |> * Apache Software Foundation, please see >> |<http://www.apache.org/>. >> |> * >> |> */ >> |> package org.apache.log4j.helpers; >> |> >> |> /** >> |> * >> |> * A RederWriterLock allows multiple readers to obtain >> |the lock at the >> |> same time >> |> * but allows only one writer at a time. >> |> * >> |> * Priority is given to waiting writers >> |> * >> |> * @author Ceki Gülcü >> |> * >> |> */ >> |> public class ReaderWriterLock { >> |> >> |> int readers = 0; >> |> int writers = 0; >> |> int waitingWriters = 0; >> |> >> |> public synchronized void getReadLock() { >> |> while(writers > 0 || waitingWriters > 0) { >> |> try {wait();} catch (InterruptedException ie) {} >> |> } >> |> readers++; >> |> } >> |> >> |> public synchronized void releaseReadLock() { >> |> readers --; >> |> if(waitingWriters >0) >> |> notifyAll(); >> |> } >> |> >> |> public synchronized void getWriteLock() { >> |> waitingWriters++; >> |> while(readers > 0 || writers > 0) { >> |> try {wait();} catch (InterruptedException ie) {} >> |> } >> |> waitingWriters--; >> |> writers++; >> |> } >> |> >> |> public synchronized void releaseWriteLock() { >> |> writers--; >> |> notifyAll(); >> |> } >> |> >> |> } >> |> >> |> >> |> >> |> 1.32 +9 -1 jakarta-log4j/tests/build.xml >> |> >> |> Index: build.xml >> |> >> |=================================================================== >> |> RCS file: /home/cvs/jakarta-log4j/tests/build.xml,v >> |> retrieving revision 1.31 >> |> retrieving revision 1.32 >> |> diff -u -r1.31 -r1.32 >> |> --- build.xml 23 May 2003 14:15:05 -0000 1.31 >> |> +++ build.xml 24 May 2003 21:04:00 -0000 1.32 >> |> @@ -409,7 +409,15 @@ >> |> <!-- ========================= Very long Tests >> |> ======================= --> >> |> <!-- >> |> >> |=========================================================== >> |====== --> >> |> >> |> - <!-- none yet, but StressCategory is a good candidate... --> >> |> + >> |> + <target name="ReaderWriterLock" depends="build, >> |cleanOutputDir"> >> |> + <junit printsummary="yes" fork="no" haltonfailure="yes"> >> |> + <classpath refid="tests.classpath"/> >> |> + <formatter type="plain" usefile="false"/> >> |> + <test >> |name="org.apache.log4j.helpers.ReaderWriterLockTestCase" /> >> |> + </junit> >> |> + </target> >> |> + >> |> >> |> </project> >> |> >> |> >> |> >> |> >> |> 1.1 >> |> >> |jakarta-log4j/tests/src/java/org/apache/log4j/helpers/Reade >> |rWriterLockTestCase.java >> |> >> |> Index: ReaderWriterLockTestCase.java >> |> >> |=================================================================== >> |> /* >> |> * >> |> >> |=========================================================== >> |================= >> |> * The Apache Software License, Version 1.1 >> |> * >> |> >> |=========================================================== >> |================= >> |> * >> |> * Copyright (C) 1999 The Apache Software >> |Foundation. All rights >> |> reserved. >> |> * >> |> * Redistribution and use in source and binary forms, >> |with or without >> |> modifica- >> |> * tion, are permitted provided that the following >> |conditions are met: >> |> * >> |> * 1. Redistributions of source code must retain the above >> |> copyright notice, >> |> * this list of conditions and the following disclaimer. >> |> * >> |> * 2. Redistributions in binary form must reproduce >> |the above copyright >> |> notice, >> |> * this list of conditions and the following >> |disclaimer in the >> |> documentation >> |> * and/or other materials provided with the distribution. >> |> * >> |> * 3. The end-user documentation included with the >> |redistribution, if >> |> any, must >> |> * include the following acknowledgment: "This product >> |> includes software >> |> * developed by the Apache Software >> |> Foundation (http://www.apache.org/)." >> |> * Alternately, this acknowledgment may appear in >> |the software >> |> itself, if >> |> * and wherever such third-party acknowledgments >> |normally appear. >> |> * >> |> * 4. The names "log4j" and "Apache Software >> |Foundation" must not be >> |> used to >> |> * endorse or promote products derived from this >> | software >> |> without prior >> |> * written permission. For written permission, >> |please contact >> |> * [EMAIL PROTECTED] >> |> * >> |> * 5. Products derived from this software may not be >> |called "Apache", >> |> nor may >> |> * "Apache" appear in their name, without prior written >> |> permission of the >> |> * Apache Software Foundation. >> |> * >> |> * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY >> |EXPRESSED OR IMPLIED >> |> WARRANTIES, >> |> * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF >> |> MERCHANTABILITY AND >> |> * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. >> | IN NO EVENT >> |> SHALL THE >> |> * APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS >> |BE LIABLE FOR ANY >> |> DIRECT, >> |> * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR >> |CONSEQUENTIAL DAMAGES >> |> (INCLU- >> |> * DING, BUT NOT LIMITED TO, PROCUREMENT OF >> |SUBSTITUTE GOODS OR >> |> SERVICES; LOSS >> |> * OF USE, DATA, OR PROFITS; OR BUSINESS >> |INTERRUPTION) HOWEVER >> |> CAUSED AND ON >> |> * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT >> |> LIABILITY, OR TORT >> |> * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN >> |ANY WAY OUT OF >> |> THE USE OF >> |> * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY >> |OF SUCH DAMAGE. >> |> * >> |> * This software consists of voluntary contributions >> |made by many >> |> individuals >> |> * on behalf of the Apache Software Foundation. For >> |> more information on the >> |> * Apache Software Foundation, please see >> |<http://www.apache.org/>. >> |> * >> |> */ >> |> >> |> package org.apache.log4j.helpers; >> |> >> |> import junit.framework.Test; >> |> import junit.framework.TestCase; >> |> import junit.framework.TestSuite; >> |> >> |> import org.apache.log4j.ConsoleAppender; >> |> import org.apache.log4j.LogManager; >> |> import org.apache.log4j.Logger; >> |> import org.apache.log4j.PatternLayout; >> |> >> |> >> |> /** >> |> * @author Ceki >> |> * >> |> * To change the template for this generated type comment go to >> |> * Window>Preferences>Java>Code Generation>Code and Comments >> |> */ >> |> public class ReaderWriterLockTestCase extends TestCase { >> |> double value1 = 0; >> |> double value2 = 0; >> |> ReaderWriterLock lock = new ReaderWriterLock(); >> |> >> |> /** >> |> * Constructor for ReaderWriterLockTestCasae. >> |> * @param arg0 >> |> */ >> |> public ReaderWriterLockTestCase(String arg0) { >> |> super(arg0); >> |> } >> |> >> |> protected void setUp() throws Exception { >> |> System.out.println("====================="); >> |> Logger root = Logger.getRootLogger(); >> |> root.addAppender(new ConsoleAppender(new >> |PatternLayout("%4r [%t] - >> |> %m%n"))); >> |> } >> |> >> |> protected void tearDown() throws Exception { >> |> System.out.println("------------------------"); >> |> LogManager.shutdown(); >> |> } >> |> >> |> public void test1() { >> |> int maxReaders = 3; >> |> int maxWriters = 2; >> |> Thread[] threads = new Thread[maxReaders + maxWriters]; >> |> >> |> for (int i = 0; i < maxReaders; i++) { >> |> threads[i] = new ReaderThread(i); >> |> } >> |> >> |> for (int i = 0; i < maxWriters; i++) { >> |> threads[maxReaders + i] = new WriterThread(i); >> |> } >> |> >> |> for (int i = 0; i < (maxWriters + maxReaders); i++) { >> |> threads[i].start(); >> |> } >> |> >> |> for (int i = 0; i < (maxWriters + maxReaders); i++) { >> |> try { >> |> threads[i].join(); >> |> } catch (InterruptedException e) { >> |> } >> |> } >> |> } >> |> >> |> public static Test suite() { >> |> TestSuite suite = new TestSuite(); >> |> suite.addTest(new ReaderWriterLockTestCase("test1")); >> |> >> |> return suite; >> |> } >> |> >> |> class ReaderThread extends Thread { >> |> ReaderThread(int i) { >> |> super("Reader-" + i); >> |> } >> |> >> |> public void run() { >> |> Logger root = Logger.getRootLogger(); >> |> root.debug("In run()"); >> |> >> |> for (int l = 0; l < 150; l++) { >> |> root.debug("Asking for read lock."); >> |> lock.getReadLock(); >> |> root.debug("Got read lock."); >> |> root.debug("Value1 is " + value1); >> |> root.debug("Value2 is " + value2); >> |> try {sleep(10);} catch (InterruptedException e) {} >> |> root.debug("About to release read lock."); >> |> lock.releaseReadLock(); >> |> } >> |> } >> |> } >> |> >> |> class WriterThread extends Thread { >> |> WriterThread(int i) { >> |> super("WRITER-" + i); >> |> } >> |> >> |> public void run() { >> |> Logger root = Logger.getRootLogger(); >> |> root.debug("In run()"); >> |> >> |> for (int l = 0; l < 50; l++) { >> |> try {sleep(30);} catch (InterruptedException e) {} >> |> root.debug("Asking for write lock."); >> |> lock.getWriteLock(); >> |> root.debug("Got write lock."); >> |> root.debug("About to increment values."); >> |> value1 += 1; >> |> value2 += 10; >> |> try {sleep(10);} catch (InterruptedException e) {} >> |> root.debug("About to release write lock."); >> |> lock.releaseWriteLock(); >> |> >> |> } >> |> } >> |> } >> |> } >> |> >> |> >> |> >> |> >> |>---------------------------------------------------------- >> |----------- >> |>To unsubscribe, e-mail: [EMAIL PROTECTED] >> |>For additional commands, e-mail: [EMAIL PROTECTED] >> | >> |-- >> |Ceki For log4j documentation consider "The complete log4j manual" >> | ISBN: 2970036908 http://www.qos.ch/shop/products/clm_t.jsp >> | >> | >> |----------------------------------------------------------- >> |---------- >> |To unsubscribe, e-mail: [EMAIL PROTECTED] >> |For additional commands, e-mail: [EMAIL PROTECTED] >> | >> >>--------------------------------------------------------------------- >>To unsubscribe, e-mail: [EMAIL PROTECTED] >>For additional commands, e-mail: [EMAIL PROTECTED] > >-- >Ceki For log4j documentation consider "The complete log4j manual" > ISBN: 2970036908 http://www.qos.ch/shop/products/clm_t.jsp > > >--------------------------------------------------------------------- >To unsubscribe, e-mail: [EMAIL PROTECTED] >For additional commands, e-mail: [EMAIL PROTECTED] This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. 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