Mercurial > hg > openjdk > jdk7 > jdk
changeset 4236:2ecb989b6fcc
6977677: 3/2 Deadlock on logging subsystem initialization
Summary: Over synchronized Logger.getLogger() deadlocks with LogManager.<clinit>via PlatformLogger
Reviewed-by: dsamersoff, never, acorn, mchung
author | dcubed |
---|---|
date | Mon, 16 May 2011 12:56:29 -0700 |
parents | e0c3fd538f1f |
children | b2db38eb3b13 |
files | src/share/classes/java/util/logging/Logger.java test/java/util/logging/LoggingDeadlock4.java |
diffstat | 2 files changed, 133 insertions(+), 3 deletions(-) [+] |
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--- a/src/share/classes/java/util/logging/Logger.java Mon May 16 17:28:18 2011 +0200 +++ b/src/share/classes/java/util/logging/Logger.java Mon May 16 12:56:29 2011 -0700 @@ -310,7 +310,20 @@ * @return a suitable Logger * @throws NullPointerException if the name is null. */ - public static synchronized Logger getLogger(String name) { + + // Synchronization is not required here. All synchronization for + // adding a new Logger object is handled by LogManager.addLogger(). + public static Logger getLogger(String name) { + // This method is intentionally not a wrapper around a call + // to getLogger(name, resourceBundleName). If it were then + // this sequence: + // + // getLogger("Foo", "resourceBundleForFoo"); + // getLogger("Foo"); + // + // would throw an IllegalArgumentException in the second call + // because the wrapper would result in an attempt to replace + // the existing "resourceBundleForFoo" with null. LogManager manager = LogManager.getLogManager(); return manager.demandLogger(name); } @@ -355,7 +368,10 @@ * a different resource bundle name. * @throws NullPointerException if the name is null. */ - public static synchronized Logger getLogger(String name, String resourceBundleName) { + + // Synchronization is not required here. All synchronization for + // adding a new Logger object is handled by LogManager.addLogger(). + public static Logger getLogger(String name, String resourceBundleName) { LogManager manager = LogManager.getLogManager(); Logger result = manager.demandLogger(name); if (result.resourceBundleName == null) { @@ -417,7 +433,10 @@ * @throws MissingResourceException if the resourceBundleName is non-null and * no corresponding resource can be found. */ - public static synchronized Logger getAnonymousLogger(String resourceBundleName) { + + // Synchronization is not required here. All synchronization for + // adding a new anonymous Logger object is handled by doSetParent(). + public static Logger getAnonymousLogger(String resourceBundleName) { LogManager manager = LogManager.getLogManager(); // cleanup some Loggers that have been GC'ed manager.drainLoggerRefQueueBounded();
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/java/util/logging/LoggingDeadlock4.java Mon May 16 12:56:29 2011 -0700 @@ -0,0 +1,111 @@ +/* + * Copyright (c) 2011, 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. + * + * 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. + */ + +/* + * @test + * @bug 6977677 + * @summary Deadlock between LogManager.<clinit> and Logger.getLogger() + * @author Daniel D. Daugherty + * @build LoggingDeadlock4 + * @run main/timeout=15 LoggingDeadlock4 + */ + +import java.awt.Container; +import java.util.concurrent.CountDownLatch; +import java.util.logging.LogManager; +import java.util.logging.Logger; + +public class LoggingDeadlock4 { + private static CountDownLatch barrier = new CountDownLatch(1); + private static CountDownLatch lmIsRunning = new CountDownLatch(1); + private static CountDownLatch logIsRunning = new CountDownLatch(1); + + public static void main(String[] args) { + System.out.println("main: LoggingDeadlock4 is starting."); + + // Loading the java.awt.Container class will create a + // sun.util.logging.PlatformLogger$JavaLogger object + // that has to be redirected when the LogManager class + // is initialized. This can cause a deadlock between + // LogManager.<clinit> and Logger.getLogger(). + try { + Class.forName("java.awt.Container"); + } catch (ClassNotFoundException cnfe) { + throw new RuntimeException("Test failed: could not load" + + " java.awt.Container." + cnfe); + } + + Thread lmThread = new Thread("LogManagerThread") { + public void run() { + // let main know LogManagerThread is running + lmIsRunning.countDown(); + + System.out.println(Thread.currentThread().getName() + + ": is running."); + + try { + barrier.await(); // wait for race to start + } catch (InterruptedException e) { + } + + LogManager manager = LogManager.getLogManager(); + } + }; + lmThread.start(); + + Thread logThread = new Thread("LoggerThread") { + public void run() { + // let main know LoggerThread is running + logIsRunning.countDown(); + + System.out.println(Thread.currentThread().getName() + + ": is running."); + + try { + barrier.await(); // wait for race to start + } catch (InterruptedException e) { + } + + Logger foo = Logger.getLogger("foo logger"); + } + }; + logThread.start(); + + try { + // wait for LogManagerThread and LoggerThread to get going + lmIsRunning.await(); + logIsRunning.await(); + } catch (InterruptedException e) { + } + + barrier.countDown(); // start the race + + try { + lmThread.join(); + logThread.join(); + } catch (InterruptedException ie) { + } + + System.out.println("main: LoggingDeadlock4 is done."); + } +}