keep track of the last time a client started a long polling operation so we can eventually use that to remove dead clients

src/net/socialgamer/cah/LongPollServlet.java

@@ -57,6 +57,7 @@ public class LongPollServlet extends CahServlet {
     final long end = start + TIMEOUT_BASE + (long) (Math.random() * TIMEOUT_RANDOMNESS);
     final User user = (User) hSession.getAttribute("user");
     assert (user != null);
+    user.contactedServer();
     // TODO we might have to synchronize on the user object?
     while (!(user.hasQueuedMessages()) && System.nanoTime() < end) {
       try {

src/net/socialgamer/cah/data/User.java

@@ -15,6 +15,8 @@ public class User {
 
   private final Object queuedMessageSynchronization = new Object();
 
+  private long lastHeardFrom = 0;
+
   public User(final String nickname) {
     this.nickname = nickname;
     queuedMessages = new PriorityBlockingQueue<QueuedMessage>();
@@ -63,4 +65,15 @@ public class User {
     return nickname;
   }
 
+  /**
+   * Update the timestamp that we have last heard from this user to the current time.
+   */
+  public void contactedServer() {
+    lastHeardFrom = System.nanoTime();
+  }
+
+  public long getLastHeardFrom() {
+    return lastHeardFrom;
+  }
+
 }