QPID-606: synchronize retrieval of application registry to avoid race conditions. This was

particularly affecting systests which use the in-VM broker.


git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/branches/M2.1@578058 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 20 insertions, 17 deletions

diff --git a/java/broker/src/main/java/org/apache/qpid/server/registry/ApplicationRegistry.java b/java/broker/src/main/java/org/apache/qpid/server/registry/ApplicationRegistry.java
index 89f0b7b39d..22fa0fab23 100644
--- a/java/broker/src/main/java/org/apache/qpid/server/registry/ApplicationRegistry.java
+++ b/java/broker/src/main/java/org/apache/qpid/server/registry/ApplicationRegistry.java
@@ -137,29 +137,32 @@ public abstract class ApplicationRegistry implements IApplicationRegistry
 
     public static IApplicationRegistry getInstance(int instanceID)
     {
-        IApplicationRegistry instance = _instanceMap.get(instanceID);
-
-        if (instance == null)
+        synchronized (IApplicationRegistry.class)
         {
-            try
+            IApplicationRegistry instance = _instanceMap.get(instanceID);
+
+            if (instance == null)
             {
-                _logger.info("Creating DEFAULT_APPLICATION_REGISTRY: " + _APPLICATION_REGISTRY + " : Instance:" + instanceID);
-                IApplicationRegistry registry = (IApplicationRegistry) Class.forName(_APPLICATION_REGISTRY).getConstructor((Class[]) null).newInstance((Object[]) null);
-                ApplicationRegistry.initialise(registry, instanceID);
-                _logger.info("Initialised Application Registry:" + instanceID);
-                return registry;
+                try
+                {
+                    _logger.info("Creating DEFAULT_APPLICATION_REGISTRY: " + _APPLICATION_REGISTRY + " : Instance:" + instanceID);
+                    IApplicationRegistry registry = (IApplicationRegistry) Class.forName(_APPLICATION_REGISTRY).getConstructor((Class[]) null).newInstance((Object[]) null);
+                    ApplicationRegistry.initialise(registry, instanceID);
+                    _logger.info("Initialised Application Registry:" + instanceID);
+                    return registry;
+                }
+                catch (Exception e)
+                {
+                    _logger.error("Error configuring application: " + e, e);
+                //throw new AMQBrokerCreationException(instanceID, "Unable to create Application Registry instance " + instanceID);
+                    throw new RuntimeException("Unable to create Application Registry", e);
+                }
             }
-            catch (Exception e)
+            else
             {
-                _logger.error("Error configuring application: " + e, e);
-                //throw new AMQBrokerCreationException(instanceID, "Unable to create Application Registry instance " + instanceID);
-                throw new RuntimeException("Unable to create Application Registry", e);
+                return instance;
             }
         }
-        else
-        {
-            return instance;
-        }
     }
 
     public void close() throws Exception