Fixed concurrency issues. JM-470

git-svn-id: http://svn.igniterealtime.org/svn/repos/messenger/trunk@3121 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/messenger/muc/HistoryStrategy.java

@@ -18,6 +18,7 @@ import org.xmpp.packet.Message;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.ListIterator;
+import java.util.concurrent.ConcurrentLinkedQueue;
 
 /**
  * <p>Multi-User Chat rooms may cache history of the conversations in the room in order to
@@ -39,7 +40,7 @@ public class HistoryStrategy {
     /**
      * List containing the history of messages.
      */
-    private LinkedList history = new LinkedList();
+    private ConcurrentLinkedQueue<Message> history = new ConcurrentLinkedQueue<Message>();
     /**
      * Default max number.
      */
@@ -159,7 +160,7 @@ public class HistoryStrategy {
             }
         }
         else if (strategyType == Type.all) {
-            history.addLast(packet);
+            history.add(packet);
         }
         else if (strategyType == Type.number) {
             if (history.size() >= strategyMaxNumber) {
@@ -169,14 +170,14 @@ public class HistoryStrategy {
                 // last room subject
                 // message because we want to preserve the room subject if
                 // possible.
-                ListIterator historyIter = history.listIterator();
+                Iterator historyIter = history.iterator();
                 while (historyIter.hasNext() && history.size() > strategyMaxNumber) {
                     if (historyIter.next() != roomSubject) {
                         historyIter.remove();
                     }
                 }
             }
-            history.addLast(packet);
+            history.add(packet);
         }
     }
 
@@ -185,8 +186,8 @@ public class HistoryStrategy {
      * 
      * @return An iterator of Message objects to be sent to the new room member.
      */
-    public Iterator getMessageHistory(){
-        LinkedList list = (LinkedList) history.clone();
+    public Iterator<Message> getMessageHistory(){
+        LinkedList<Message> list = new LinkedList<Message>(history);
         return list.iterator();
     }
 
@@ -197,8 +198,8 @@ public class HistoryStrategy {
      * 
      * @return A list iterator of Message objects positioned at the end of the list.
      */
-    public ListIterator getReverseMessageHistory(){
-        LinkedList list = (LinkedList) history.clone();
+    public ListIterator<Message> getReverseMessageHistory(){
+        LinkedList<Message> list = new LinkedList<Message>(history);
         return list.listIterator(list.size());
     }