Importing upstream Jetty jetty-9.2.1.v20140609

[gigi.git] / lib / jetty / org / eclipse / jetty / util / preventers / GCThreadLeakPreventer.java

diff --git a/lib/jetty/org/eclipse/jetty/util/preventers/GCThreadLeakPreventer.java b/lib/jetty/org/eclipse/jetty/util/preventers/GCThreadLeakPreventer.java
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+//
+//  ========================================================================
+//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.util.preventers;
+
+import java.lang.reflect.Method;
+
+/**
+ * GCThreadLeakPreventer
+ *
+ * Prevents a call to sun.misc.GC.requestLatency pinning a webapp classloader
+ * by calling it with a non-webapp classloader. The problem appears to be that
+ * when this method is called, a daemon thread is created which takes the 
+ * context classloader. A known caller of this method is the RMI impl. See
+ * http://stackoverflow.com/questions/6626680/does-java-garbage-collection-log-entry-full-gc-system-mean-some-class-called
+ * 
+ * This preventer will start the thread with the longest possible interval, although
+ * subsequent calls can vary that. Recommend to only use this class if you're doing
+ * RMI.
+ * 
+ * Inspired by Tomcat JreMemoryLeakPrevention.
+ *
+ */
+public class GCThreadLeakPreventer extends AbstractLeakPreventer
+{
+    /* ------------------------------------------------------------ */
+    /** 
+     * @see org.eclipse.jetty.util.preventers.AbstractLeakPreventer#prevent(java.lang.ClassLoader)
+     */
+    @Override
+    public void prevent(ClassLoader loader)
+    {
+        try
+        {
+            Class clazz = Class.forName("sun.misc.GC");
+            Method requestLatency = clazz.getMethod("requestLatency", new Class[] {long.class});
+            requestLatency.invoke(null, Long.valueOf(Long.MAX_VALUE-1));
+        }
+        catch (ClassNotFoundException e)
+        {
+            LOG.ignore(e);
+        }
+        catch (Exception e)
+        {
+            LOG.warn(e);
+        }
+    }
+
+}