QPID-1454 : Synchronize round the setting and usage of _failoverLatch, with a new lock.

git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk@718554 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 12 insertions, 3 deletions

diff --git a/qpid/java/client/src/main/java/org/apache/qpid/client/protocol/AMQProtocolHandler.java b/qpid/java/client/src/main/java/org/apache/qpid/client/protocol/AMQProtocolHandler.java
index 20beec5cc4..2389c9e2da 100644
--- a/qpid/java/client/src/main/java/org/apache/qpid/client/protocol/AMQProtocolHandler.java
+++ b/qpid/java/client/src/main/java/org/apache/qpid/client/protocol/AMQProtocolHandler.java
@@ -164,6 +164,9 @@ public class AMQProtocolHandler extends IoHandlerAdapter
     /** Defines the default timeout to use for synchronous protocol commands. */
     private final long DEFAULT_SYNC_TIMEOUT = Long.getLong("amqj.default_syncwrite_timeout", 1000 * 30);
 
+    /** Object to lock on when changing the latch */
+    private Object _failoverLatchChange = new Object();
+
     /**
      * Creates a new protocol handler, associated with the specified client connection instance.
      *
@@ -774,9 +777,12 @@ public class AMQProtocolHandler extends IoHandlerAdapter
 
     public void blockUntilNotFailingOver() throws InterruptedException
     {
-        if (_failoverLatch != null)
+        synchronized(_failoverLatchChange)
         {
-            _failoverLatch.await();
+            if (_failoverLatch != null)
+            {
+                _failoverLatch.await();
+            }
         }
     }
 
@@ -792,7 +798,10 @@ public class AMQProtocolHandler extends IoHandlerAdapter
 
     public void setFailoverLatch(CountDownLatch failoverLatch)
     {
-        _failoverLatch = failoverLatch;
+        synchronized (_failoverLatchChange)
+        {
+            _failoverLatch = failoverLatch;
+        }
     }
 
     public AMQConnection getConnection()