--- old/src/share/classes/sun/awt/AppContext.java	2011-08-19 10:22:55.990366402 +0200
+++ new/src/share/classes/sun/awt/AppContext.java	2011-08-19 10:22:55.715369839 +0200
@@ -46,6 +46,7 @@
 import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * The AppContext is a table referenced by ThreadGroup which stores
@@ -195,6 +196,8 @@
     }
 
     static {
+        numAppContexts = new AtomicInteger(0);
+		        
         // On the main Thread, we get the ThreadGroup, make a corresponding
         // AppContext, and instantiate the Java EventQueue.  This way, legacy
         // code is unaffected by the move to multiple AppContext ability.
@@ -209,7 +212,6 @@
                     parentThreadGroup = currentThreadGroup.getParent();
                 }
                 mainAppContext = new AppContext(currentThreadGroup);
-                numAppContexts = 1;
                 return mainAppContext;
             }
         });
@@ -222,7 +224,7 @@
      * number is 1.  If so, it returns the sole AppContext without
      * checking Thread.currentThread().
      */
-    private static volatile int numAppContexts;
+    private static final AtomicInteger numAppContexts;
 
     /*
      * The context ClassLoader that was used to create this AppContext.
@@ -243,7 +245,7 @@
      * @since   1.2
      */
     AppContext(ThreadGroup threadGroup) {
-        numAppContexts++;
+        numAppContexts.incrementAndGet();
 
         this.threadGroup = threadGroup;
         threadGroup2appContext.put(threadGroup, this);
@@ -278,7 +280,7 @@
      * @since   1.2
      */
     public final static AppContext getAppContext() {
-        if (numAppContexts == 1)   // If there's only one system-wide,
+        if (numAppContexts.get() == 1)   // If there's only one system-wide,
             return mainAppContext; // return the main system AppContext.
 
         AppContext appContext = threadAppContext.get();
@@ -503,7 +505,7 @@
             this.table.clear(); // Clear out the Hashtable to ease garbage collection
         }
 
-        numAppContexts--;
+        numAppContexts.decrementAndGet();
 
         mostRecentKeyValue = null;
     }