https://issues.apache.org/jira/browse/AMQ-6164 - allow journal write batching on a single destination

activemq-broker/src/main/java/org/apache/activemq/broker/region/Queue.java

@@ -829,8 +829,6 @@ public class Queue extends BaseDestination implements Task, UsageListener, Index
         producerExchange.incrementSend();
         do {
             checkUsage(context, producerExchange, message);
-            sendLock.lockInterruptibly();
-            try {
             message.getMessageId().setBrokerSequenceId(getDestinationSequenceId());
             if (store != null && message.isPersistent()) {
                 message.getMessageId().setFutureOrSequenceLong(null);
@@ -854,9 +852,6 @@ public class Queue extends BaseDestination implements Task, UsageListener, Index
             if(tryOrderedCursorAdd(message, context)) {
                 break;
             }
-            } finally {
-                sendLock.unlock();
-            }
         } while (started.get());
 
         if (store == null || (!context.isInTransaction() && !message.isPersistent())) {

activemq-broker/src/main/java/org/apache/activemq/store/memory/MemoryMessageStore.java

@@ -59,13 +59,13 @@ public class MemoryMessageStore extends AbstractMessageStore {
         synchronized (messageTable) {
             messageTable.put(message.getMessageId(), message);
             incMessageStoreStatistics(getMessageStoreStatistics(), message);
-        }
             message.incrementReferenceCount();
             message.getMessageId().setFutureOrSequenceLong(sequenceId++);
             if (indexListener != null) {
                 indexListener.onAdd(new IndexListener.MessageContext(context, message, null));
             }
         }
+    }
 
     // public void addMessageReference(ConnectionContext context,MessageId
     // messageId,long expirationTime,String messageRef)

activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/KahaDBStore.java

@@ -326,10 +326,9 @@ public class KahaDBStore extends MessageDatabase implements PersistenceAdapter {
         return task;
     }
 
+    // with asyncTaskMap locked
     protected void addQueueTask(KahaDBMessageStore store, StoreQueueTask task) throws IOException {
-        synchronized (store.asyncTaskMap) {
         store.asyncTaskMap.put(new AsyncJobKey(task.getMessage().getMessageId(), store.getDestination()), task);
-        }
         this.queueExecutor.execute(task);
     }
 
@@ -390,10 +389,12 @@ public class KahaDBStore extends MessageDatabase implements PersistenceAdapter {
                 message.getMessageId().setFutureOrSequenceLong(future);
                 message.setRecievedByDFBridge(true); // flag message as concurrentStoreAndDispatch
                 result.aquireLocks();
+                synchronized (asyncTaskMap) {
                     addQueueTask(this, result);
                     if (indexListener != null) {
                         indexListener.onAdd(new IndexListener.MessageContext(context, message, null));
                     }
+                }
                 return future;
             } else {
                 return super.asyncAddQueueMessage(context, message);

activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/LevelDBStore.scala

@@ -758,7 +758,7 @@ class LevelDBStore extends LockableServiceSupport with BrokerServiceAware with P
       uow.addCompleteListener({
         message.decrementReferenceCount()
       })
-      val sequence = lastSeq.synchronized {
+      lastSeq.synchronized {
         val seq = lastSeq.incrementAndGet()
         message.getMessageId.setFutureOrSequenceLong(seq);
         // null context on xa recovery, we want to bypass the cursor & pending adds as it will be reset
@@ -768,9 +768,8 @@ class LevelDBStore extends LockableServiceSupport with BrokerServiceAware with P
             def run(): Unit = pendingCursorAdds.synchronized { pendingCursorAdds.remove(seq) }
           }))
         }
-        seq
+        uow.enqueue(key, seq, message, delay)
       }
-      uow.enqueue(key, sequence, message, delay)
     }
 
     override def asyncAddQueueMessage(context: ConnectionContext, message: Message) = asyncAddQueueMessage(context, message, false)