The Switch Event thread is the thread that processes events coming from all switches. 42/5142/1
authorAsad Ahmed <asaahmed@cisco.com>
Wed, 5 Feb 2014 23:44:31 +0000 (15:44 -0800)
committerAsad Ahmed <asaahmed@cisco.com>
Wed, 5 Feb 2014 23:44:31 +0000 (15:44 -0800)
Right now its very fragile as an unhandled exception can cause the thread to die causing
the controller to be unusable. Making the thread more tolerant of exceptions and making
the shutdown of the thread more deterministic.

Change-Id: I31c31f012229de8e124c0c13fa651513daaf6776
Signed-off-by: Asad Ahmed <asaahmed@cisco.com>
opendaylight/protocol_plugins/openflow/src/main/java/org/opendaylight/controller/protocol_plugin/openflow/core/internal/Controller.java

index 72ee7a6..63dd0bc 100644 (file)
@@ -48,6 +48,7 @@ public class Controller implements IController, CommandProvider, IPluginInConnec
             .getLogger(Controller.class);
     private ControllerIO controllerIO;
     private Thread switchEventThread;
+    private volatile boolean shutdownSwitchEventThread;// default to false
     private ConcurrentHashMap<Long, ISwitch> switches;
     private PriorityBlockingQueue<SwitchEvent> switchEvents;
     // only 1 message listener per OFType
@@ -69,6 +70,12 @@ public class Controller implements IController, CommandProvider, IPluginInConnec
 
             while (true) {
                 try {
+                    if(shutdownSwitchEventThread) {
+                        // break out of the infinite loop
+                        // if you are shutting down
+                        logger.info("Switch Event Thread is shutting down");
+                        break;
+                    }
                     SwitchEvent ev = switchEvents.take();
                     SwitchEvent.SwitchEventType eType = ev.getEventType();
                     ISwitch sw = ev.getSwitch();
@@ -104,12 +111,14 @@ public class Controller implements IController, CommandProvider, IPluginInConnec
                         logger.error("Unknown switch event {}", eType.ordinal());
                     }
                 } catch (InterruptedException e) {
-                    switchEvents.clear();
-                    return;
+                    // nothing to do except retry
+                } catch (Exception e) {
+                    // log the exception and retry
+                    logger.warn("Exception in Switch Event Thread is {}" ,e);
                 }
             }
+            switchEvents.clear();
         }
-
     }
 
     /**
@@ -167,6 +176,7 @@ public class Controller implements IController, CommandProvider, IPluginInConnec
             ((SwitchHandler) entry.getValue()).stop();
             it.remove();
         }
+        shutdownSwitchEventThread = true;
         switchEventThread.interrupt();
         try {
             controllerIO.shutDown();