From fb9d09744df07a4b7a7681e6cabe38af1f675190 Mon Sep 17 00:00:00 2001
From: Erich Duda <eduda@redhat.com>
Date: Wed, 25 May 2016 10:28:38 +0200
Subject: [PATCH] ARTEMIS-538 - [Artemis Testsuite]
 JMSFailoverListenerTest#testManualFailover fails

ActiveMQConnection implements FailoverEventListener which executes client's
FailoverEventListeners in separated threads in background. The old implementation
does not guarantee ordering of their executions. The commit improves the
implementation to guarantee it.
---
 .../artemis/jms/client/ActiveMQConnection.java        | 11 +++++++++--
 .../jms/cluster/JMSFailoverListenerTest.java          |  3 +--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/artemis-jms-client/src/main/java/org/apache/activemq/artemis/jms/client/ActiveMQConnection.java b/artemis-jms-client/src/main/java/org/apache/activemq/artemis/jms/client/ActiveMQConnection.java
index e8122d08f3..80597e3706 100644
--- a/artemis-jms-client/src/main/java/org/apache/activemq/artemis/jms/client/ActiveMQConnection.java
+++ b/artemis-jms-client/src/main/java/org/apache/activemq/artemis/jms/client/ActiveMQConnection.java
@@ -35,6 +35,8 @@ import javax.jms.TopicSession;
 import java.lang.ref.WeakReference;
 import java.util.HashSet;
 import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 import org.apache.activemq.artemis.api.core.ActiveMQException;
 import org.apache.activemq.artemis.api.core.ActiveMQExceptionType;
@@ -48,6 +50,7 @@ import org.apache.activemq.artemis.api.jms.ActiveMQJMSConstants;
 import org.apache.activemq.artemis.core.client.impl.ClientSessionInternal;
 import org.apache.activemq.artemis.core.version.Version;
 import org.apache.activemq.artemis.reader.MessageUtil;
+import org.apache.activemq.artemis.utils.ActiveMQThreadFactory;
 import org.apache.activemq.artemis.utils.ConcurrentHashSet;
 import org.apache.activemq.artemis.utils.UUIDGenerator;
 import org.apache.activemq.artemis.utils.VersionLoader;
@@ -113,6 +116,8 @@ public class ActiveMQConnection extends ActiveMQConnectionForContextImpl impleme
 
    private final FailoverEventListener failoverListener = new FailoverEventListenerImpl(this);
 
+   private final ExecutorService failoverListenerExecutor = Executors.newFixedThreadPool(1, ActiveMQThreadFactory.defaultThreadFactory());
+
    private final Version thisVersion;
 
    private final int dupsOKBatchSize;
@@ -353,6 +358,8 @@ public class ActiveMQConnection extends ActiveMQConnectionForContextImpl impleme
             }
          }
 
+         failoverListenerExecutor.shutdown();
+
          closed = true;
       }
       catch (ActiveMQException e) {
@@ -759,12 +766,12 @@ public class ActiveMQConnection extends ActiveMQConnectionForContextImpl impleme
 
                if (failoverListener != null) {
 
-                  new Thread(new Runnable() {
+                  conn.failoverListenerExecutor.execute(new Runnable() {
                      @Override
                      public void run() {
                         failoverListener.failoverEvent(eventType);
                      }
-                  }).start();
+                  });
                }
             }
             catch (JMSException e) {
diff --git a/tests/integration-tests/src/test/java/org/apache/activemq/artemis/tests/integration/jms/cluster/JMSFailoverListenerTest.java b/tests/integration-tests/src/test/java/org/apache/activemq/artemis/tests/integration/jms/cluster/JMSFailoverListenerTest.java
index ed5dcae095..5cb23b3ef2 100644
--- a/tests/integration-tests/src/test/java/org/apache/activemq/artemis/tests/integration/jms/cluster/JMSFailoverListenerTest.java
+++ b/tests/integration-tests/src/test/java/org/apache/activemq/artemis/tests/integration/jms/cluster/JMSFailoverListenerTest.java
@@ -56,7 +56,6 @@ import javax.jms.Queue;
 import javax.jms.Session;
 import javax.jms.TextMessage;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -312,7 +311,7 @@ public class JMSFailoverListenerTest extends ActiveMQTestBase {
 
    private static class MyFailoverListener implements FailoverEventListener {
 
-      private List<FailoverEventType> eventTypeList = Collections.synchronizedList(new ArrayList<FailoverEventType>());
+      private List<FailoverEventType> eventTypeList = new ArrayList<>();
 
       public FailoverEventType get(int element) {
          waitForElements(element + 1);