Index: /tc6.0.x/trunk/java/org/apache/catalina/core/StandardWrapper.java
===================================================================
--- /tc6.0.x/trunk/java/org/apache/catalina/core/StandardWrapper.java	(revision 566663)
+++ /tc6.0.x/trunk/java/org/apache/catalina/core/StandardWrapper.java	(working copy)
@@ -28,6 +28,7 @@
 import java.util.HashSet;
 import java.util.Properties;
 import java.util.Stack;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.security.AccessController;
 import java.security.PrivilegedActionException;
 import java.security.PrivilegedExceptionAction;
@@ -135,7 +136,7 @@
      * The count of allocations that are currently active (even if they
      * are for the same instance, as will be true on a non-STM servlet).
      */
-    protected int countAllocated = 0;
+    protected AtomicInteger countAllocated = new AtomicInteger(0);
 
 
     /**
@@ -340,7 +341,7 @@
      */
     public int getCountAllocated() {
 
-        return (this.countAllocated);
+        return (this.countAllocated.get());
 
     }
 
@@ -817,7 +818,7 @@
             if (!singleThreadModel) {
                 if (log.isTraceEnabled())
                     log.trace("  Returning non-STM instance");
-                countAllocated++;
+                countAllocated.incrementAndGet();
                 return (instance);
             }
 
@@ -825,7 +826,7 @@
 
         synchronized (instancePool) {
 
-            while (countAllocated >= nInstances) {
+            while (countAllocated.get() >= nInstances) {
                 // Allocate a new instance if possible, or else wait
                 if (nInstances < maxInstances) {
                     try {
@@ -847,7 +848,7 @@
             }
             if (log.isTraceEnabled())
                 log.trace("  Returning allocated STM instance");
-            countAllocated++;
+            countAllocated.incrementAndGet();
             return (Servlet) instancePool.pop();
 
         }
@@ -868,13 +869,13 @@
 
         // If not SingleThreadModel, no action is required
         if (!singleThreadModel) {
-            countAllocated--;
+            countAllocated.decrementAndGet();
             return;
         }
 
         // Unlock and free this instance
         synchronized (instancePool) {
-            countAllocated--;
+            countAllocated.decrementAndGet();
             instancePool.push(servlet);
             instancePool.notify();
         }
@@ -1347,13 +1348,13 @@
 
         // Loaf a while if the current instance is allocated
         // (possibly more than once if non-STM)
-        if (countAllocated > 0) {
+        if (countAllocated.get() > 0) {
             int nRetries = 0;
             long delay = unloadDelay / 20;
-            while ((nRetries < 21) && (countAllocated > 0)) {
+            while ((nRetries < 21) && (countAllocated.get() > 0)) {
                 if ((nRetries % 10) == 0) {
                     log.info(sm.getString("standardWrapper.waiting",
-                                          new Integer(countAllocated)));
+                                          new Integer(countAllocated.get())));
                 }
                 try {
                     Thread.sleep(delay);