Author: markt
Date: Wed Oct 28 19:25:31 2009
New Revision: 830736
URL: http://svn.apache.org/viewvc?rev=830736&view=rev
Log:
Add a workaround for a common cause of locked files.
Modified:
tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
tomcat/trunk/java/org/apache/catalina/core/LocalStrings.properties
Modified:
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=830736&r1=830735&r2=830736&view=diff
==============================================================================
---
tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
(original)
+++
tomcat/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
Wed Oct 28 19:25:31 2009
@@ -17,21 +17,41 @@
package org.apache.catalina.core;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLConnection;
+
import javax.imageio.ImageIO;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleEvent;
import org.apache.catalina.LifecycleListener;
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.res.StringManager;
/**
- * Provide a workaround for known places where the Java Runtime environment
uses
+ * Provide a workaround for known places where the Java Runtime environment can
+ * cause a memory leak or lock files.
+ * <p>
+ * Memory leaks occur when JRE code 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.
+ * <p>
+ * Locked usually files occur when a resource inside a JAR is accessed without
+ * first disabling Jar URL connection caching. The workaround is to disable
this
+ * caching by default.
*/
public class JreMemoryLeakPreventionListener implements LifecycleListener {
+ protected static final Log log =
+ LogFactory.getLog(JreMemoryLeakPreventionListener.class);
+ protected static final StringManager sm =
+ StringManager.getManager(Constants.Package);
+
@Override
public void lifecycleEvent(LifecycleEvent event) {
// Initialise these classes when Tomcat starts
@@ -42,7 +62,6 @@
*
* 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
@@ -54,6 +73,31 @@
// issue.
ImageIO.getCacheDirectory();
+ /*
+ * Several components end up opening JarURLConnections without
first
+ * disabling chaching. This effectively locks the file. Whilst more
+ * noticeable and harder to ignore on Windows, it affects all
+ * operating systems.
+ *
+ * Those libraries/components known to trigger this issue include:
+ * - log4j versions 1.2.15 and earlier
+ * - javax.xml.bind.JAXBContext.newInstance()
+ */
+
+ // Set the default JAR URL caching policy to not to cache
+ try {
+ // Doesn't matter that this JAR doesn't exist - just as long as
+ // the URL is well-formed
+ URL url = new URL("jar:file://dummy.jar!/dummy.txt");
+ URLConnection uConn = url.openConnection();
+ uConn.setDefaultUseCaches(false);
+ } catch (MalformedURLException e) {
+ log.error(sm.getString(
+ "jreLeakListener.jarUrlConnCacheFail"), e);
+ } catch (IOException e) {
+ log.error(sm.getString(
+ "jreLeakListener.jarUrlConnCacheFail"), e);
+ }
}
}
Modified: tomcat/trunk/java/org/apache/catalina/core/LocalStrings.properties
URL:
http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/core/LocalStrings.properties?rev=830736&r1=830735&r2=830736&view=diff
==============================================================================
--- tomcat/trunk/java/org/apache/catalina/core/LocalStrings.properties
(original)
+++ tomcat/trunk/java/org/apache/catalina/core/LocalStrings.properties Wed Oct
28 19:25:31 2009
@@ -65,6 +65,7 @@
httpHostMapper.container=This container is not a StandardHost
interceptorValve.alreadyStarted=InterceptorValve has already been started
interceptorValve.notStarted=InterceptorValve has not yet been started
+jreLeakListener.jarUrlConnCacheFail=Failed to disable Jar URL connection
caching by default
naming.wsdlFailed=Failed to find wsdl file: {0}
naming.bindFailed=Failed to bind object: {0}
naming.jmxRegistrationFailed=Failed to register in JMX: {0}
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