Index: java/org/apache/catalina/core/AsyncContextImpl.java
===================================================================
--- java/org/apache/catalina/core/AsyncContextImpl.java	(revision 1849198)
+++ java/org/apache/catalina/core/AsyncContextImpl.java	(working copy)
@@ -111,6 +111,7 @@
         } finally {
             context.fireRequestDestroyEvent(request.getRequest());
             clearServletRequestResponse();
+            this.context.decrementInProgressAsyncCount();
             context.unbind(Globals.IS_SECURITY_ENABLED, oldCL);
         }
     }
@@ -205,6 +206,7 @@
                     request, applicationDispatcher, servletRequest, servletResponse);
             this.request.getCoyoteRequest().action(ActionCode.ASYNC_DISPATCH, null);
             clearServletRequestResponse();
+            this.context.decrementInProgressAsyncCount();
         }
     }
 
@@ -311,6 +313,7 @@
                     ActionCode.ASYNC_START, this);
 
             this.context = context;
+            context.incrementInProgressAsyncCount();
             this.servletRequest = request;
             this.servletResponse = response;
             this.hasOriginalRequestAndResponse = originalRequestResponse;
@@ -377,6 +380,17 @@
     }
 
 
+
+    @Override
+    public boolean isAvailable() {
+        Context context = this.context;
+        if (context == null) {
+            return false;
+        }
+        return context.getState().isAvailable();
+    }
+
+
     public void setErrorState(Throwable t, boolean fireOnError) {
         if (t!=null) request.setAttribute(RequestDispatcher.ERROR_EXCEPTION, t);
         request.getCoyoteRequest().action(ActionCode.ASYNC_ERROR, null);
Index: java/org/apache/catalina/core/StandardContext.java
===================================================================
--- java/org/apache/catalina/core/StandardContext.java	(revision 1849198)
+++ java/org/apache/catalina/core/StandardContext.java	(working copy)
@@ -820,10 +820,24 @@
 
     private boolean allowMultipleLeadingForwardSlashInPath = false;
 
+    private final AtomicLong inProgressAsyncCount = new AtomicLong(0);
 
+
     // ----------------------------------------------------- Context Properties
 
     @Override
+    public void incrementInProgressAsyncCount() {
+        inProgressAsyncCount.incrementAndGet();
+    }
+
+
+    @Override
+    public void decrementInProgressAsyncCount() {
+        inProgressAsyncCount.decrementAndGet();
+    }
+
+
+    @Override
     public void setAllowMultipleLeadingForwardSlashInPath(
             boolean allowMultipleLeadingForwardSlashInPath) {
         this.allowMultipleLeadingForwardSlashInPath = allowMultipleLeadingForwardSlashInPath;
@@ -5325,6 +5339,22 @@
             broadcaster.sendNotification(notification);
         }
 
+        // Context has been removed from Mapper at this point (so no new
+        // requests will be mapped) but is still available.
+
+        // Give the in progress async requests a chance to complete
+        long limit = System.currentTimeMillis() + unloadDelay;
+        while (inProgressAsyncCount.get() > 0 && System.currentTimeMillis() < limit) {
+            try {
+                Thread.sleep(50);
+            } catch (InterruptedException e) {
+                // TODO
+                log.info(sm.getString(""), e);
+            }
+        }
+
+        // Once the state is set to STOPPING, the Context will report itself as
+        // not available and any in progress async requests will timeout
         setState(LifecycleState.STOPPING);
 
         // Binding thread
Index: java/org/apache/catalina/startup/FailedContext.java
===================================================================
--- java/org/apache/catalina/startup/FailedContext.java	(revision 1849198)
+++ java/org/apache/catalina/startup/FailedContext.java	(working copy)
@@ -809,4 +809,9 @@
     }
     @Override
     public boolean getAllowMultipleLeadingForwardSlashInPath() { return false; }
+
+    @Override
+    public void incrementInProgressAsyncCount() { /* NO-OP */ }
+    @Override
+    public void decrementInProgressAsyncCount() { /* NO-OP */ }
 }
\ No newline at end of file
Index: java/org/apache/catalina/Context.java
===================================================================
--- java/org/apache/catalina/Context.java	(revision 1849198)
+++ java/org/apache/catalina/Context.java	(working copy)
@@ -1863,4 +1863,10 @@
      *         otherwise <code>false</code>
      */
     public boolean getAllowMultipleLeadingForwardSlashInPath();
+
+
+    public void incrementInProgressAsyncCount();
+
+
+    public void decrementInProgressAsyncCount();
 }
Index: java/org/apache/coyote/AbstractProcessor.java
===================================================================
--- java/org/apache/coyote/AbstractProcessor.java	(revision 1849198)
+++ java/org/apache/coyote/AbstractProcessor.java	(working copy)
@@ -639,6 +639,10 @@
                 if ((now - asyncStart) > asyncTimeout) {
                     doTimeoutAsync();
                 }
+            } else if (!asyncStateMachine.isAvailable()) {
+                // Timeout the async process if the associated web application
+                // is no longer running.
+                doTimeoutAsync();
             }
         }
     }
Index: java/org/apache/coyote/AsyncContextCallback.java
===================================================================
--- java/org/apache/coyote/AsyncContextCallback.java	(revision 1849198)
+++ java/org/apache/coyote/AsyncContextCallback.java	(working copy)
@@ -17,12 +17,20 @@
 package org.apache.coyote;
 
 /**
- * Provides a mechanism for the Coyote connectors to signal to a
- * {@link javax.servlet.AsyncContext} implementation that an action, such as
- * firing event listeners needs to be taken. It is implemented in this manner
- * so that the org.apache.coyote package does not have a dependency on the
+ * Provides a mechanism for the Coyote connectors to communicate with the
+ * {@link javax.servlet.AsyncContext}. It is implemented in this manner so that
+ * the org.apache.coyote package does not have a dependency on the
  * org.apache.catalina package.
  */
 public interface AsyncContextCallback {
     public void fireOnComplete();
+
+    /**
+     * Reports if the web application associated with this async request is
+     * available.
+     *
+     * @return {@code true} if the associated web application is available,
+     *         otherwise {@code false}
+     */
+    public boolean isAvailable();
 }
Index: java/org/apache/coyote/AsyncStateMachine.java
===================================================================
--- java/org/apache/coyote/AsyncStateMachine.java	(revision 1849198)
+++ java/org/apache/coyote/AsyncStateMachine.java	(working copy)
@@ -483,6 +483,16 @@
     }
 
 
+    synchronized boolean isAvailable() {
+        if (asyncCtxt == null) {
+            // Async processing has probably been completed in another thread.
+            // Trigger a timeout to make sure the Processor is cleaned up.
+            return false;
+        }
+        return asyncCtxt.isAvailable();
+    }
+
+
     synchronized void recycle() {
         // Use lastAsyncStart to determine if this instance has been used since
         // it was last recycled. If it hasn't there is no need to recycle again
Index: test/org/apache/tomcat/unittest/TesterContext.java
===================================================================
--- test/org/apache/tomcat/unittest/TesterContext.java	(revision 1849198)
+++ test/org/apache/tomcat/unittest/TesterContext.java	(working copy)
@@ -1274,4 +1274,9 @@
     }
     @Override
     public boolean getAllowMultipleLeadingForwardSlashInPath() { return false; }
+
+    @Override
+    public void incrementInProgressAsyncCount() { /* NO-OP */ }
+    @Override
+    public void decrementInProgressAsyncCount() { /* NO-OP */ }
 }