Make FlowOperationsProcessor thread-safe with synchronized modifier

Different threads could call run(), satisfy() and fail() method.
Each of the methods reads/writes multiple fields during the method call.
These method calls need to be synchronized to gurantee to see the
latest value.

Change-Id: Ic252b56e0902170d7e0fdb83f96f0fb2e55ec56b

@@ -587,7 +587,7 @@ public class FlowRuleManager
         }
 
         @Override
-        public void run() {
+        public synchronized void run() {
             if (stages.size() > 0) {
                 process(stages.remove(0));
             } else if (!hasFailed.get() && context != null) {
@@ -632,7 +632,7 @@ public class FlowRuleManager
             }
         }
 
-        void satisfy(DeviceId devId) {
+        synchronized void satisfy(DeviceId devId) {
             pendingDevices.remove(devId);
             if (pendingDevices.isEmpty()) {
                 operationsService.execute(this);
@@ -641,7 +641,7 @@ public class FlowRuleManager
 
 
 
-        void fail(DeviceId devId, Set<? extends FlowRule> failures) {
+        synchronized void fail(DeviceId devId, Set<? extends FlowRule> failures) {
             hasFailed.set(true);
             pendingDevices.remove(devId);
             if (pendingDevices.isEmpty()) {