1 files changed, 71 insertions, 0 deletions
diff --git a/qpid/java/broker/src/main/java/org/apache/qpid/server/flow/AbstractFlowCreditManager.java b/qpid/java/broker/src/main/java/org/apache/qpid/server/flow/AbstractFlowCreditManager.java
new file mode 100644
index 0000000000..cfe5aedd61
--- /dev/null
+++ b/qpid/java/broker/src/main/java/org/apache/qpid/server/flow/AbstractFlowCreditManager.java
@@ -0,0 +1,71 @@
+/*
+*
+* Licensed to the Apache Software Foundation (ASF) under one
+* or more contributor license agreements.  See the NOTICE file
+* distributed with this work for additional information
+* regarding copyright ownership.  The ASF licenses this file
+* to you under the Apache License, Version 2.0 (the
+* "License"); you may not use this file except in compliance
+* with the License.  You may obtain a copy of the License at
+*
+*   http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing,
+* software distributed under the License is distributed on an
+* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+* KIND, either express or implied.  See the License for the
+* specific language governing permissions and limitations
+* under the License.
+*
+*/
+package org.apache.qpid.server.flow;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.Set;
+import java.util.HashSet;
+
+public abstract class AbstractFlowCreditManager implements FlowCreditManager
+{
+    protected final AtomicBoolean _suspended = new AtomicBoolean(false);
+    private final Set<FlowCreditManagerListener> _listeners = new HashSet<FlowCreditManagerListener>();
+
+    public final void addStateListener(FlowCreditManagerListener listener)
+    {
+        synchronized(_listeners)
+        {
+            _listeners.add(listener);
+        }
+    }
+
+    public final boolean removeListener(FlowCreditManagerListener listener)
+    {
+        synchronized(_listeners)
+        {
+            return _listeners.remove(listener);
+        }
+    }
+
+    private void notifyListeners(final boolean suspended)
+    {
+        synchronized(_listeners)
+        {
+            for(FlowCreditManagerListener listener : _listeners)
+            {
+                listener.creditStateChanged(!suspended);
+            }
+        }
+    }
+
+    protected final void setSuspended(final boolean suspended)
+    {
+        if(_suspended.compareAndSet(!suspended, suspended))
+        {
+            notifyListeners(suspended);
+        }
+    }
+
+    protected final void notifyIncreaseBytesCredit()
+    {
+        notifyListeners(false);
+    }
+}