Stop trying to flush clients after the server shuts down

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5633 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/server/ClientManager.java

@@ -105,12 +105,13 @@ public class ClientManager
 
         // start up an interval that will check for expired clients and flush them from the bowels
         // of the server
-        new Interval(omgr) {
+        _flushClients = new Interval(omgr) {
             @Override
             public void expired () {
                 flushClients();
             }
-        }.schedule(CLIENT_FLUSH_INTERVAL, true);
+        };
+        _flushClients.schedule(CLIENT_FLUSH_INTERVAL, true);
     }
 
     /**
@@ -127,6 +128,8 @@ public class ClientManager
     {
         log.info("Client manager shutting down [ccount=" + _usermap.size() + "].");
 
+        _flushClients.cancel();
+
         // inform all of our clients that they are being shut down
         synchronized (_usermap) {
             for (PresentsSession pc : _usermap.values()) {
@@ -573,6 +576,9 @@ public class ClientManager
     /** Tracks registered {@link ClientObserver}s. */
     protected ObserverList<ClientObserver> _clobservers = ObserverList.newSafeInOrder();
 
+    /** Interval to flush expired clients. */
+    protected Interval _flushClients;
+
     // our injected dependencies
     @Inject protected PresentsDObjectMgr _omgr;