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| author | Aidan Skinner <aidan@apache.org> | 2008-04-23 23:56:38 +0000 |
|---|---|---|
| committer | Aidan Skinner <aidan@apache.org> | 2008-04-23 23:56:38 +0000 |
| commit | 5518fd899d97459bcd8c45b850da447697a60fe8 (patch) | |
| tree | 30e500327125a70939e2ff4c9ac79f366ad7d0b1 /qpid/dotnet/Qpid.Client/Client/Util/FlowControlQueue.cs | |
| parent | 65971bf662ccc0df167b23ecb831f1ccb3d5e475 (diff) | |
| download | qpid-python-5518fd899d97459bcd8c45b850da447697a60fe8.tar.gz | |
QPID-832 sync from M2.x
git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk@651113 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'qpid/dotnet/Qpid.Client/Client/Util/FlowControlQueue.cs')
| -rw-r--r-- | qpid/dotnet/Qpid.Client/Client/Util/FlowControlQueue.cs | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/qpid/dotnet/Qpid.Client/Client/Util/FlowControlQueue.cs b/qpid/dotnet/Qpid.Client/Client/Util/FlowControlQueue.cs new file mode 100644 index 0000000000..87bb2a2859 --- /dev/null +++ b/qpid/dotnet/Qpid.Client/Client/Util/FlowControlQueue.cs @@ -0,0 +1,98 @@ +/*
+ *
+ * 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.
+ *
+ */
+using System;
+using System.Collections;
+using System.Text;
+using System.Threading;
+using Apache.Qpid.Collections;
+using Apache.Qpid.Common;
+
+namespace Apache.Qpid.Client.Util
+{
+ internal delegate void ThresholdMethod(int currentCount);
+
+ /// <summary>
+ /// Basic bounded queue used to implement prefetching.
+ /// Notice we do the callbacks here asynchronously to
+ /// avoid adding more complexity to the channel impl.
+ /// </summary>
+ internal class FlowControlQueue
+ {
+ private BlockingQueue _queue = new LinkedBlockingQueue();
+ private int _itemCount;
+ private int _lowerBound;
+ private int _upperBound;
+ private ThresholdMethod _underThreshold;
+ private ThresholdMethod _overThreshold;
+
+ public FlowControlQueue(
+ int lowerBound,
+ int upperBound,
+ ThresholdMethod underThreshold,
+ ThresholdMethod overThreshold
+ )
+ {
+ _lowerBound = lowerBound;
+ _upperBound = upperBound;
+ _underThreshold = underThreshold;
+ _overThreshold = overThreshold;
+ }
+
+ public void Enqueue(object item)
+ {
+ _queue.EnqueueBlocking(item);
+ int count = Interlocked.Increment(ref _itemCount);
+ if ( _overThreshold != null )
+ {
+ if ( count == _upperBound )
+ {
+ _overThreshold.BeginInvoke(
+ count, new AsyncCallback(OnAsyncCallEnd),
+ _overThreshold
+ );
+ }
+ }
+ }
+
+ public object Dequeue()
+ {
+ object item = _queue.DequeueBlocking();
+ int count = Interlocked.Decrement(ref _itemCount);
+ if ( _underThreshold != null )
+ {
+ if ( count == _lowerBound )
+ {
+ _underThreshold.BeginInvoke(
+ count, new AsyncCallback(OnAsyncCallEnd),
+ _underThreshold
+ );
+ }
+ }
+ return item;
+ }
+
+ private void OnAsyncCallEnd(IAsyncResult res)
+ {
+ ThresholdMethod method = (ThresholdMethod)res.AsyncState;
+ method.EndInvoke(res);
+ }
+ }
+}
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