From 54417748830c84bf2a4d6eae6bb3ea0e2265f7ee Mon Sep 17 00:00:00 2001
From: Robert Davies <rajdavies@apache.org>
Date: Mon, 16 Jun 2008 06:30:25 +0000
Subject: [PATCH] Fix for https://issues.apache.org/activemq/browse/AMQ-1799

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@668061 13f79535-47bb-0310-9956-ffa450edef68
---
 .../region/cursors/StoreDurableSubscriberCursor.java     | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/activemq-core/src/main/java/org/apache/activemq/broker/region/cursors/StoreDurableSubscriberCursor.java b/activemq-core/src/main/java/org/apache/activemq/broker/region/cursors/StoreDurableSubscriberCursor.java
index 5c34affde3..b7735440f6 100755
--- a/activemq-core/src/main/java/org/apache/activemq/broker/region/cursors/StoreDurableSubscriberCursor.java
+++ b/activemq-core/src/main/java/org/apache/activemq/broker/region/cursors/StoreDurableSubscriberCursor.java
@@ -20,9 +20,9 @@ import java.io.IOException;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.CopyOnWriteArrayList;
 import org.apache.activemq.advisory.AdvisorySupport;
 import org.apache.activemq.broker.Broker;
 import org.apache.activemq.broker.ConnectionContext;
@@ -47,7 +47,7 @@ public class StoreDurableSubscriberCursor extends AbstractPendingMessageCursor {
     private String clientId;
     private String subscriberName;
     private Map<Destination, TopicStorePrefetch> topics = new HashMap<Destination, TopicStorePrefetch>();
-    private LinkedList<PendingMessageCursor> storePrefetches = new LinkedList<PendingMessageCursor>();
+    private List<PendingMessageCursor> storePrefetches = new CopyOnWriteArrayList<PendingMessageCursor>();
     private boolean started;
     private PendingMessageCursor nonPersistent;
     private PendingMessageCursor currentCursor;
@@ -322,7 +322,10 @@ public class StoreDurableSubscriberCursor extends AbstractPendingMessageCursor {
                 }
             }
             // round-robin
-            storePrefetches.addLast(storePrefetches.removeFirst());
+            if (storePrefetches.size()>1) {
+                PendingMessageCursor first = storePrefetches.remove(0);
+                storePrefetches.add(first);
+            }
         }
         return currentCursor;
     }