Author: markt
Date: Wed Oct 21 20:36:23 2009
New Revision: 828196
URL: http://svn.apache.org/viewvc?rev=828196&view=rev
Log:
Somewhat ironically, the call to java.beans.Introspector.flushCaches() that is
meant to prevent memory leaks now causes a leak on reload due to a change in
1.6.0_15 onwards.
Add a listener that prevents the leak.
Added:
tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
Modified:
tomcat/trunk/conf/server.xml
Modified: tomcat/trunk/conf/server.xml
URL:
http://svn.apache.org/viewvc/tomcat/trunk/conf/server.xml?rev=828196&r1=828195&r2=828196&view=diff
==============================================================================
--- tomcat/trunk/conf/server.xml (original)
+++ tomcat/trunk/conf/server.xml Wed Oct 21 20:36:23 2009
@@ -25,6 +25,8 @@
<Listener className="org.apache.catalina.core.AprLifecycleListener"
SSLEngine="on" />
<!--Initialize Jasper prior to webapps are loaded. Documentation at
/docs/jasper-howto.html -->
<Listener className="org.apache.catalina.core.JasperListener" />
+ <!-- Prevent memory leaks due to use of particular java/javax APIs-->
+ <Listener
className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
<!-- JMX Support for the Tomcat server. Documentation at
/docs/non-existent.html -->
<Listener className="org.apache.catalina.mbeans.ServerLifecycleListener" />
<Listener
className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
Added:
tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java?rev=828196&view=auto
==============================================================================
---
tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
(added)
+++
tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
Wed Oct 21 20:36:23 2009
@@ -0,0 +1,60 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.catalina.core;
+
+import javax.imageio.ImageIO;
+
+import org.apache.catalina.Lifecycle;
+import org.apache.catalina.LifecycleEvent;
+import org.apache.catalina.LifecycleListener;
+
+/**
+ * Provide a workaround for known places where the Java Runtime environment
uses
+ * the context class loader to load a singleton as this will cause a memory
leak
+ * if a web application class loader happens to be the context class loader at
+ * the time. The work-around is to initialise these singletons when Tomcat's
+ * common class loader is the context class loader.
+ */
+public class JreMemoryLeakPreventionListener implements LifecycleListener {
+
+ @Override
+ public void lifecycleEvent(LifecycleEvent event) {
+ // Initialise these classes when Tomcat starts
+ if (Lifecycle.INIT_EVENT.equals(event.getType())) {
+ /*
+ * Several components end up calling:
+ * sun.awt.AppContext.getAppContext()
+ *
+ * Those libraries / components known to trigger memory leaks due
to
+ * eventual calls to getAppContext() are:
+ *
+ * - Google Web Toolkit via its use of javax.imageio
+ * - Tomcat via its use of java.beans.Introspector.flushCaches() in
+ * 1.6.0_15 onwards
+ * - others TBD
+ */
+
+ // Trigger a call to sun.awt.AppContext.getAppContext(). This will
+ // pin the common class loader in memory but that shouldn't be an
+ // issue.
+ ImageIO.getCacheDirectory();
+
+ }
+ }
+
+}
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