Author: markt
Date: Mon Jun 24 15:33:33 2013
New Revision: 1496098

URL: http://svn.apache.org/r1496098
Log:
Changes to java.beans.Introspector#flushCaches() mean that AppContext 
protection is not required from 1.7.0_02 onwards.
Changes to AppContext meant the memory leak protection required a graphical 
environment from 1.7.0_25 onwards.

Modified:
    tomcat/tc7.0.x/trunk/   (props changed)
    
tomcat/tc7.0.x/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
    tomcat/tc7.0.x/trunk/webapps/docs/changelog.xml
    tomcat/tc7.0.x/trunk/webapps/docs/config/listeners.xml

Propchange: tomcat/tc7.0.x/trunk/
------------------------------------------------------------------------------
  Merged /tomcat/trunk:r1496061

Modified: 
tomcat/tc7.0.x/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
URL: 
http://svn.apache.org/viewvc/tomcat/tc7.0.x/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java?rev=1496098&r1=1496097&r2=1496098&view=diff
==============================================================================
--- 
tomcat/tc7.0.x/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
 (original)
+++ 
tomcat/tc7.0.x/trunk/java/org/apache/catalina/core/JreMemoryLeakPreventionListener.java
 Mon Jun 24 15:33:33 2013
@@ -59,12 +59,30 @@ public class JreMemoryLeakPreventionList
     private static final StringManager sm =
         StringManager.getManager(Constants.Package);
 
+    private static final boolean IS_JAVA_7_OR_LATER;
+
+    static {
+        boolean isJava7OrLater;
+        try {
+            Class.forName("java.util.Objects");
+            isJava7OrLater = true;
+        } catch (ClassNotFoundException e) {
+            isJava7OrLater = false;
+        }
+        IS_JAVA_7_OR_LATER = isJava7OrLater;
+    }
+
     /**
      * Protect against the memory leak caused when the first call to
      * <code>sun.awt.AppContext.getAppContext()</code> is triggered by a web
-     * application. Defaults to <code>true</code>.
+     * application. Defaults to <code>true</code> for Java 6 and earlier (since
+     * it is used by {@link java.beans.Introspector#flushCaches()}) but 
defaults
+     * to <code>false</code> for Java 7 and later since
+     * {@link java.beans.Introspector#flushCaches()} no longer uses AppContext
+     * from 1.7.0_02 onwards. Also, from 1.7.0_25 onwards, calling this method
+     * requires a graphical environment and starts an AWT thread.
      */
-    private boolean appContextProtection = true;
+    private boolean appContextProtection = !IS_JAVA_7_OR_LATER;
     public boolean isAppContextProtection() { return appContextProtection; }
     public void setAppContextProtection(boolean appContextProtection) {
         this.appContextProtection = appContextProtection;
@@ -248,8 +266,15 @@ public class JreMemoryLeakPreventionList
                  * 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
+                 *   in 1.6.0_15 to 1.7.0_01. From 1.7.0_02 onwards use of
+                 *   AppContext by Introspector.flushCaches() was replaced with
+                 *   ThreadGroupContext
                  * - others TBD
+                 *
+                 * From 1.7.0_25 onwards, a call to
+                 * sun.awt.AppContext.getAppContext() results in a thread being
+                 * started named AWT-AppKit that requires a graphic environment
+                 * to be available.
                  */
                 
                 // Trigger a call to sun.awt.AppContext.getAppContext(). This

Modified: tomcat/tc7.0.x/trunk/webapps/docs/changelog.xml
URL: 
http://svn.apache.org/viewvc/tomcat/tc7.0.x/trunk/webapps/docs/changelog.xml?rev=1496098&r1=1496097&r2=1496098&view=diff
==============================================================================
--- tomcat/tc7.0.x/trunk/webapps/docs/changelog.xml (original)
+++ tomcat/tc7.0.x/trunk/webapps/docs/changelog.xml Mon Jun 24 15:33:33 2013
@@ -92,6 +92,12 @@
         and when running as a service) since Tomcat will not be able to do any
         useful work. (markt)
       </fix>
+      <fix>
+        Update the <code>JreMemoryLeakPreventionListener</code> to take account
+        of changes in the behaviour of
+        <code>java.beans.Introspector.flushCaches()</code> and
+        <code>sun.awt.AppContext.getAppContext()</code> in Java 7. (markt)
+      </fix>
     </changelog>
   </subsection>
   <subsection name="Cluster">

Modified: tomcat/tc7.0.x/trunk/webapps/docs/config/listeners.xml
URL: 
http://svn.apache.org/viewvc/tomcat/tc7.0.x/trunk/webapps/docs/config/listeners.xml?rev=1496098&r1=1496097&r2=1496098&view=diff
==============================================================================
--- tomcat/tc7.0.x/trunk/webapps/docs/config/listeners.xml (original)
+++ tomcat/tc7.0.x/trunk/webapps/docs/config/listeners.xml Mon Jun 24 15:33:33 
2013
@@ -177,9 +177,11 @@
         <p>Enables protection so that calls to
         <code>sun.awt.AppContext.getAppContext()</code> triggered by a web
         application do not result in a memory leak. Note that a call to this
-        method will be triggered as part of the web application stop process so
-        it is strongly recommended that this protection is enabled. The default
-        is <code>true</code>.</p>
+        method will be triggered as part of the web application stop process
+        when running on Java 6 and earlier. It is therefore strongly 
recommended
+        that this protection is enabled when running on Java 6 and earlier. The
+        default is <code>true</code> for Java 6 and earlier versions. The
+        default is <code>false</code> for Java 7 and later versions.</p>
       </attribute>
 
       <attribute name="AWTThreadProtection" required="false">



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