commit 99fcee16b35d4b5047a60497ffde6a65eb2c7eb4
author Pankaj Berde <pankaj@onlab.us> Mon Mar 18 09:41:53 2013 -0700
committer Pankaj Berde <pankaj@onlab.us> Mon Mar 18 09:41:53 2013 -0700
tree 98a80207a65db266f8829032c53de121e5e68d02
parent 4c5a622802cd3fe364f0f92691f75edfce74c170

fixed #229: handling rapid switch flapping race conditions gracefully

src/main/java/net/floodlightcontroller/core/internal/Controller.java

diff --git a/src/main/java/net/floodlightcontroller/core/internal/Controller.java b/src/main/java/net/floodlightcontroller/core/internal/Controller.java
index 4057bc9..60dbc69 100644
--- a/src/main/java/net/floodlightcontroller/core/internal/Controller.java
+++ b/src/main/java/net/floodlightcontroller/core/internal/Controller.java
@@ -797,6 +797,7 @@
         }
         
         protected void checkSwitchReady() {
+        	Boolean controlRequested = Boolean.TRUE;
             if (state.hsState == HandshakeState.FEATURES_REPLY &&
                     state.hasDescription && state.hasGetConfigReply) {
                 
@@ -825,6 +826,7 @@
 									new RoleChangeCallback());
 						} catch (RegistryException e) {
 							log.debug("Registry error: {}", e.getMessage());
+							controlRequested = Boolean.FALSE;
 						}
                     	
                     	
@@ -858,6 +860,16 @@
                         state.firstRoleReplyReceived = true;
                     }
                 }
+                if (!controlRequested) {
+                	// yield to allow other thread(s) to release control
+                	try {
+						Thread.sleep(10);
+					} catch (InterruptedException e) {
+						// Ignore interruptions						
+					}
+                	// safer to bounce the switch to reconnect here than proceeding further
+                	sw.channel.close();
+                }
             }
         }