commit ea762bb15d7c9652c5cf13f6efd13bb00ae28487
author Aled Sage <aled.sage@gmail.com> Fri Apr 01 12:32:39 2016 +0100
committer Alex Heneveld <alex.heneveld@cloudsoftcorp.com> Fri Apr 01 15:27:52 2016 +0100
tree 764b9f8399baea480aebca34dfa669aee117a0ca
parent c2c1484b1f5a1236b1bbc820faca42c426b2456f

Entity.getSubscriptionTracker synchronization

Avoid calling getSubscriptionContext() while holding lock on 
AbstractEntity.this. See discussion in https://github.com/apache/brooklyn-server/pull/96

core/src/main/java/org/apache/brooklyn/core/entity/AbstractEntity.java

diff --git a/core/src/main/java/org/apache/brooklyn/core/entity/AbstractEntity.java b/core/src/main/java/org/apache/brooklyn/core/entity/AbstractEntity.java
index 09834af..58767e4 100644
--- a/core/src/main/java/org/apache/brooklyn/core/entity/AbstractEntity.java
+++ b/core/src/main/java/org/apache/brooklyn/core/entity/AbstractEntity.java
@@ -1492,9 +1492,13 @@
         }
 
         protected SubscriptionTracker getSubscriptionTracker() {
+            // TODO Would be nice to simplify concurrent model, and not synchronize on
+            // AbstractEntity.this; perhaps could get rid of lazy-initialisation, but then
+            // would need to first ensure `managementSupport` is definitely initialised.
+            SubscriptionContext subscriptionContext = getSubscriptionContext();
             synchronized (AbstractEntity.this) {
                 if (_subscriptionTracker == null) {
-                    _subscriptionTracker = new SubscriptionTracker(getSubscriptionContext());
+                    _subscriptionTracker = new SubscriptionTracker(subscriptionContext);
                 }
                 return _subscriptionTracker;
             }