Author: markt Date: Fri May 20 11:18:55 2016 New Revision: 1744713 URL: http://svn.apache.org/viewvc?rev=1744713&view=rev Log: Remove clearReferencesStatic option
Modified: tomcat/trunk/java/org/apache/catalina/core/StandardContext.java tomcat/trunk/java/org/apache/catalina/core/mbeans-descriptors.xml tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoaderBase.java tomcat/trunk/test/org/apache/catalina/loader/TestWebappClassLoaderWeaving.java tomcat/trunk/webapps/docs/changelog.xml tomcat/trunk/webapps/docs/config/context.xml Modified: tomcat/trunk/java/org/apache/catalina/core/StandardContext.java URL: http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/core/StandardContext.java?rev=1744713&r1=1744712&r2=1744713&view=diff ============================================================================== --- tomcat/trunk/java/org/apache/catalina/core/StandardContext.java (original) +++ tomcat/trunk/java/org/apache/catalina/core/StandardContext.java Fri May 20 11:18:55 2016 @@ -713,20 +713,6 @@ public class StandardContext extends Con private boolean clearReferencesRmiTargets = true; /** - * Should Tomcat attempt to null out any static or final fields from loaded - * classes when a web application is stopped as a work around for apparent - * garbage collection bugs and application coding errors? There have been - * some issues reported with log4j when this option is true. Applications - * without memory leaks using recent JVMs should operate correctly with this - * option set to <code>false</code>. If not specified, the default value of - * <code>false</code> will be used. - * - * @deprecated This option will be removed in Tomcat 8.5 - */ - @Deprecated - private boolean clearReferencesStatic = false; - - /** * Should Tomcat attempt to terminate threads that have been started by the * web application? Stopping threads is performed via the deprecated (for * good reason) <code>Thread.stop()</code> method and is likely to result in @@ -2593,38 +2579,6 @@ public class StandardContext extends Con /** - * @return the clearReferencesStatic flag for this Context. - * - * @deprecated This option will be removed in Tomcat 8.5 - */ - @Deprecated - public boolean getClearReferencesStatic() { - - return (this.clearReferencesStatic); - - } - - - /** - * Set the clearReferencesStatic feature for this Context. - * - * @param clearReferencesStatic The new flag value - * - * @deprecated This option will be removed in Tomcat 8.5 - */ - @Deprecated - public void setClearReferencesStatic(boolean clearReferencesStatic) { - - boolean oldClearReferencesStatic = this.clearReferencesStatic; - this.clearReferencesStatic = clearReferencesStatic; - support.firePropertyChange("clearReferencesStatic", - oldClearReferencesStatic, - this.clearReferencesStatic); - - } - - - /** * @return the clearReferencesStopThreads flag for this Context. */ public boolean getClearReferencesStopThreads() { @@ -5077,8 +5031,6 @@ public class StandardContext extends Con // created. setClassLoaderProperty("clearReferencesRmiTargets", getClearReferencesRmiTargets()); - setClassLoaderProperty("clearReferencesStatic", - getClearReferencesStatic()); setClassLoaderProperty("clearReferencesStopThreads", getClearReferencesStopThreads()); setClassLoaderProperty("clearReferencesStopTimerThreads", Modified: tomcat/trunk/java/org/apache/catalina/core/mbeans-descriptors.xml URL: http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/core/mbeans-descriptors.xml?rev=1744713&r1=1744712&r2=1744713&view=diff ============================================================================== --- tomcat/trunk/java/org/apache/catalina/core/mbeans-descriptors.xml (original) +++ tomcat/trunk/java/org/apache/catalina/core/mbeans-descriptors.xml Fri May 20 11:18:55 2016 @@ -86,10 +86,6 @@ description="Should Tomcat look for memory leaks in RMI Targets and clear them if found as a work around for application coding errors?" type="boolean"/> - <attribute name="clearReferencesStatic" - description="Deprecated. Will be removed in Tomcat 8.5. Should Tomcat attempt to null out any static or final fields from loaded classes when a web application is stopped as a work around for apparent garbage collection bugs and application coding errors?" - type="boolean"/> - <attribute name="clearReferencesStopThreads" description="Should Tomcat attempt to terminate threads that have been started by the web application? Advisable to be used only in a development environment." type="boolean"/> Modified: tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoaderBase.java URL: http://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoaderBase.java?rev=1744713&r1=1744712&r2=1744713&view=diff ============================================================================== --- tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoaderBase.java (original) +++ tomcat/trunk/java/org/apache/catalina/loader/WebappClassLoaderBase.java Fri May 20 11:18:55 2016 @@ -26,7 +26,6 @@ import java.lang.ref.Reference; import java.lang.ref.WeakReference; import java.lang.reflect.Field; import java.lang.reflect.Method; -import java.lang.reflect.Modifier; import java.net.URI; import java.net.URISyntaxException; import java.net.URL; @@ -336,20 +335,6 @@ public abstract class WebappClassLoaderB private boolean clearReferencesRmiTargets = true; /** - * Should Tomcat attempt to null out any static or final fields from loaded - * classes when a web application is stopped as a work around for apparent - * garbage collection bugs and application coding errors? There have been - * some issues reported with log4j when this option is true. Applications - * without memory leaks using recent JVMs should operate correctly with this - * option set to <code>false</code>. If not specified, the default value of - * <code>false</code> will be used. - * - * @deprecated This option will be removed in Tomcat 8.5 - */ - @Deprecated - private boolean clearReferencesStatic = false; - - /** * Should Tomcat attempt to terminate threads that have been started by the * web application? Stopping threads is performed via the deprecated (for * good reason) <code>Thread.stop()</code> method and is likely to result in @@ -543,32 +528,6 @@ public abstract class WebappClassLoaderB /** - * Return the clearReferencesStatic flag for this Context. - * @return <code>true</code> if the classloader should attempt to set to null - * static final fields in loaded classes - * - * @deprecated This option will be removed in Tomcat 8.5 - */ - @Deprecated - public boolean getClearReferencesStatic() { - return (this.clearReferencesStatic); - } - - - /** - * Set the clearReferencesStatic feature for this Context. - * - * @param clearReferencesStatic The new flag value - * - * @deprecated This option will be removed in Tomcat 8.5 - */ - @Deprecated - public void setClearReferencesStatic(boolean clearReferencesStatic) { - this.clearReferencesStatic = clearReferencesStatic; - } - - - /** * @return the clearReferencesStopThreads flag for this Context. */ public boolean getClearReferencesStopThreads() { @@ -704,7 +663,6 @@ public abstract class WebappClassLoaderB base.resources = this.resources; base.delegate = this.delegate; base.state = LifecycleState.NEW; - base.clearReferencesStatic = this.clearReferencesStatic; base.clearReferencesStopThreads = this.clearReferencesStopThreads; base.clearReferencesStopTimerThreads = this.clearReferencesStopTimerThreads; base.clearReferencesLogFactoryRelease = this.clearReferencesLogFactoryRelease; @@ -1560,12 +1518,6 @@ public abstract class WebappClassLoaderB clearReferencesRmiTargets(); } - // Null out any static or final fields from loaded classes, - // as a workaround for apparent garbage collection bugs - if (clearReferencesStatic) { - clearReferencesStaticFinal(); - } - // Clear the IntrospectionUtils cache. IntrospectionUtils.clear(); @@ -1645,131 +1597,6 @@ public abstract class WebappClassLoaderB } } - - private final void clearReferencesStaticFinal() { - - Collection<ResourceEntry> values = resourceEntries.values(); - Iterator<ResourceEntry> loadedClasses = values.iterator(); - // - // walk through all loaded class to trigger initialization for - // any uninitialized classes, otherwise initialization of - // one class may call a previously cleared class. - while(loadedClasses.hasNext()) { - ResourceEntry entry = loadedClasses.next(); - if (entry.loadedClass != null) { - Class<?> clazz = entry.loadedClass; - try { - Field[] fields = clazz.getDeclaredFields(); - for (int i = 0; i < fields.length; i++) { - if(Modifier.isStatic(fields[i].getModifiers())) { - fields[i].get(null); - break; - } - } - } catch(Throwable t) { - // Ignore - } - } - } - loadedClasses = values.iterator(); - while (loadedClasses.hasNext()) { - ResourceEntry entry = loadedClasses.next(); - if (entry.loadedClass != null) { - Class<?> clazz = entry.loadedClass; - try { - Field[] fields = clazz.getDeclaredFields(); - for (int i = 0; i < fields.length; i++) { - Field field = fields[i]; - int mods = field.getModifiers(); - if (field.getType().isPrimitive() - || (field.getName().indexOf('$') != -1)) { - continue; - } - if (Modifier.isStatic(mods)) { - try { - field.setAccessible(true); - if (Modifier.isFinal(mods)) { - if (!((field.getType().getName().startsWith("java.")) - || (field.getType().getName().startsWith("javax.")))) { - nullInstance(field.get(null)); - } - } else { - field.set(null, null); - if (log.isDebugEnabled()) { - log.debug("Set field " + field.getName() - + " to null in class " + clazz.getName()); - } - } - } catch (Throwable t) { - ExceptionUtils.handleThrowable(t); - if (log.isDebugEnabled()) { - log.debug("Could not set field " + field.getName() - + " to null in class " + clazz.getName(), t); - } - } - } - } - } catch (Throwable t) { - ExceptionUtils.handleThrowable(t); - if (log.isDebugEnabled()) { - log.debug("Could not clean fields for class " + clazz.getName(), t); - } - } - } - } - - } - - - private void nullInstance(Object instance) { - if (instance == null) { - return; - } - Field[] fields = instance.getClass().getDeclaredFields(); - for (int i = 0; i < fields.length; i++) { - Field field = fields[i]; - int mods = field.getModifiers(); - if (field.getType().isPrimitive() - || (field.getName().indexOf('$') != -1)) { - continue; - } - try { - field.setAccessible(true); - if (Modifier.isStatic(mods) && Modifier.isFinal(mods)) { - // Doing something recursively is too risky - continue; - } - Object value = field.get(instance); - if (null != value) { - Class<? extends Object> valueClass = value.getClass(); - if (!loadedByThisOrChild(valueClass)) { - if (log.isDebugEnabled()) { - log.debug("Not setting field " + field.getName() + - " to null in object of class " + - instance.getClass().getName() + - " because the referenced object was of type " + - valueClass.getName() + - " which was not loaded by this web application class loader."); - } - } else { - field.set(instance, null); - if (log.isDebugEnabled()) { - log.debug("Set field " + field.getName() - + " to null in class " + instance.getClass().getName()); - } - } - } - } catch (Throwable t) { - ExceptionUtils.handleThrowable(t); - if (log.isDebugEnabled()) { - log.debug("Could not set field " + field.getName() - + " to null in object instance of class " - + instance.getClass().getName(), t); - } - } - } - } - @SuppressWarnings("deprecation") // thread.stop() private void clearReferencesThreads() { Modified: tomcat/trunk/test/org/apache/catalina/loader/TestWebappClassLoaderWeaving.java URL: http://svn.apache.org/viewvc/tomcat/trunk/test/org/apache/catalina/loader/TestWebappClassLoaderWeaving.java?rev=1744713&r1=1744712&r2=1744713&view=diff ============================================================================== --- tomcat/trunk/test/org/apache/catalina/loader/TestWebappClassLoaderWeaving.java (original) +++ tomcat/trunk/test/org/apache/catalina/loader/TestWebappClassLoaderWeaving.java Fri May 20 11:18:55 2016 @@ -239,7 +239,6 @@ public class TestWebappClassLoaderWeavin } - @SuppressWarnings("deprecation") @Test public void testCopiedClassLoaderExcludesResourcesAndTransformers() throws Exception { @@ -266,9 +265,6 @@ public class TestWebappClassLoaderWeavin assertEquals("getClearReferencesLogFactoryRelease did not match.", Boolean.valueOf(this.loader.getClearReferencesLogFactoryRelease()), Boolean.valueOf(copiedLoader.getClearReferencesLogFactoryRelease())); - assertEquals("getClearReferencesStatic did not match.", - Boolean.valueOf(this.loader.getClearReferencesStatic()), - Boolean.valueOf(copiedLoader.getClearReferencesStatic())); assertEquals("getClearReferencesStopThreads did not match.", Boolean.valueOf(this.loader.getClearReferencesStopThreads()), Boolean.valueOf(copiedLoader.getClearReferencesStopThreads())); Modified: tomcat/trunk/webapps/docs/changelog.xml URL: http://svn.apache.org/viewvc/tomcat/trunk/webapps/docs/changelog.xml?rev=1744713&r1=1744712&r2=1744713&view=diff ============================================================================== --- tomcat/trunk/webapps/docs/changelog.xml (original) +++ tomcat/trunk/webapps/docs/changelog.xml Fri May 20 11:18:55 2016 @@ -59,6 +59,13 @@ Ensure NPE will not be thrown during deployment when scanning jar files without MANIFEST.MF file. (violetagg) </fix> + <scode> + Remove the <code>clearReferencesStatic</code> option from + <code>StandardContext</code>. It was known to cause problems with some + libraries (such as log4j) and was only linked to suspected memory leaks + rather than known memory leaks. It had been disabled by default with no + increase in the reports of memory leaks for some time. (markt) + </scode> </changelog> </subsection> <subsection name="Coyote"> Modified: tomcat/trunk/webapps/docs/config/context.xml URL: http://svn.apache.org/viewvc/tomcat/trunk/webapps/docs/config/context.xml?rev=1744713&r1=1744712&r2=1744713&view=diff ============================================================================== --- tomcat/trunk/webapps/docs/config/context.xml (original) +++ tomcat/trunk/webapps/docs/config/context.xml Fri May 20 11:18:55 2016 @@ -698,19 +698,6 @@ If not specified, the default value of <code>true</code> will be used.</p> </attribute> - <attribute name="clearReferencesStatic" required="false"> - <p>If <code>true</code>, Tomcat attempts to null out any static or final - fields from loaded classes when a web application is stopped as a work - around for apparent garbage collection bugs and application coding - errors. There have been some issues reported with log4j when this - is <code>true</code>. Applications without memory leaks using recent - JVMs should operate correctly with this attribute set to - <code>false</code>. If not specified, the default value of - <code>false</code> will be used.</p> - <p>This attribute has been deprecated and will be removed in Tomcat - 8.5.</p> - </attribute> - <attribute name="clearReferencesStopThreads" required="false"> <p>If <code>true</code>, Tomcat attempts to terminate threads that have been started by the web application. Stopping threads is performed via --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@tomcat.apache.org For additional commands, e-mail: dev-h...@tomcat.apache.org