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| 1 | +//****************************************************************************************************** |
| 2 | +// StaticTimer.cs - Gbtc |
| 3 | +// |
| 4 | +// Copyright © 2016, Grid Protection Alliance. All Rights Reserved. |
| 5 | +// |
| 6 | +// Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See |
| 7 | +// the NOTICE file distributed with this work for additional information regarding copyright ownership. |
| 8 | +// The GPA licenses this file to you under the MIT License (MIT), the "License"; you may |
| 9 | +// not use this file except in compliance with the License. You may obtain a copy of the License at: |
| 10 | +// |
| 11 | +// http://opensource.org/licenses/MIT |
| 12 | +// |
| 13 | +// Unless agreed to in writing, the subject software distributed under the License is distributed on an |
| 14 | +// "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the |
| 15 | +// License for the specific language governing permissions and limitations. |
| 16 | +// |
| 17 | +// Code Modification History: |
| 18 | +// ---------------------------------------------------------------------------------------------------- |
| 19 | +// 11/10/2016 - Stephen C. Wills |
| 20 | +// Generated original version of source code. |
| 21 | +// |
| 22 | +//****************************************************************************************************** |
| 23 | + |
| 24 | +using System; |
| 25 | +using System.Collections.Concurrent; |
| 26 | +using System.Collections.Generic; |
| 27 | + |
| 28 | +namespace GSF.Threading |
| 29 | +{ |
| 30 | + /// <summary> |
| 31 | + /// Represents a timer manager which registers callbacks |
| 32 | + /// with existing timers to reduce thread pool queue burden. |
| 33 | + /// </summary> |
| 34 | + public class StaticTimer |
| 35 | + { |
| 36 | + #region [ Members ] |
| 37 | + |
| 38 | + // Nested Types |
| 39 | + private class TimerAction |
| 40 | + { |
| 41 | + private WeakAction m_action; |
| 42 | + private CancellationToken m_cancellationToken; |
| 43 | + |
| 44 | + public TimerAction(Action action, CancellationToken cancellationToken) |
| 45 | + { |
| 46 | + m_action = new WeakAction(action); |
| 47 | + m_cancellationToken = cancellationToken; |
| 48 | + } |
| 49 | + |
| 50 | + public bool IsCancelled |
| 51 | + { |
| 52 | + get |
| 53 | + { |
| 54 | + return m_cancellationToken.IsCancelled; |
| 55 | + } |
| 56 | + } |
| 57 | + |
| 58 | + public bool TryInvoke() |
| 59 | + { |
| 60 | + return m_action.TryInvoke(); |
| 61 | + } |
| 62 | + } |
| 63 | + |
| 64 | + // Fields |
| 65 | + private readonly ConcurrentDictionary<int, ConcurrentQueue<TimerAction>> m_dataStreamMonitorActions; |
| 66 | + |
| 67 | + #endregion |
| 68 | + |
| 69 | + #region [ Constructors ] |
| 70 | + |
| 71 | + /// <summary> |
| 72 | + /// Creates a new instance of the <see cref="StaticTimer"/> class. |
| 73 | + /// </summary> |
| 74 | + public StaticTimer() |
| 75 | + { |
| 76 | + m_dataStreamMonitorActions = new ConcurrentDictionary<int, ConcurrentQueue<TimerAction>>(); |
| 77 | + } |
| 78 | + |
| 79 | + #endregion |
| 80 | + |
| 81 | + #region [ Methods ] |
| 82 | + |
| 83 | + /// <summary> |
| 84 | + /// Registers the given callback with the timer running at the given interval. |
| 85 | + /// </summary> |
| 86 | + /// <param name="interval">The interval at which to run the timer.</param> |
| 87 | + /// <param name="monitorAction">The action to be performed when the timer is triggered.</param> |
| 88 | + public ICancellationToken RegisterDataStreamMonitor(int interval, Action monitorAction) |
| 89 | + { |
| 90 | + CancellationToken cancellationToken = new CancellationToken(); |
| 91 | + RegisterDataStreamMonitor(interval, new TimerAction(monitorAction, cancellationToken)); |
| 92 | + return cancellationToken; |
| 93 | + } |
| 94 | + |
| 95 | + private void RegisterDataStreamMonitor(int interval, TimerAction monitorAction) |
| 96 | + { |
| 97 | + ConcurrentQueue<TimerAction> newQueue = null; |
| 98 | + ConcurrentQueue<TimerAction> queue; |
| 99 | + |
| 100 | + lock (m_dataStreamMonitorActions) |
| 101 | + { |
| 102 | + queue = m_dataStreamMonitorActions.GetOrAdd(interval, i => newQueue = new ConcurrentQueue<TimerAction>()); |
| 103 | + queue.Enqueue(monitorAction); |
| 104 | + } |
| 105 | + |
| 106 | + if (queue == newQueue) |
| 107 | + StartTimer(interval, queue); |
| 108 | + } |
| 109 | + |
| 110 | + private void StartTimer(int interval, ConcurrentQueue<TimerAction> queue) |
| 111 | + { |
| 112 | + MonitorDataStream(interval, queue, new List<TimerAction>()); |
| 113 | + } |
| 114 | + |
| 115 | + private void MonitorDataStream(int interval, ConcurrentQueue<TimerAction> queue, List<TimerAction> list) |
| 116 | + { |
| 117 | + TimerAction action; |
| 118 | + |
| 119 | + for (int i = 0; i < list.Count; i++) |
| 120 | + { |
| 121 | + action = list[i]; |
| 122 | + |
| 123 | + // False here indicates that the |
| 124 | + // action has been garbage collected |
| 125 | + if (action.IsCancelled || !action.TryInvoke()) |
| 126 | + { |
| 127 | + int end = list.Count - 1; |
| 128 | + list[i] = list[end]; |
| 129 | + list.RemoveAt(end); |
| 130 | + i--; |
| 131 | + } |
| 132 | + } |
| 133 | + |
| 134 | + // The queue is only used to populate the |
| 135 | + // list from outside the async loop |
| 136 | + while (queue.TryDequeue(out action)) |
| 137 | + list.Add(action); |
| 138 | + |
| 139 | + if (list.Count > 0) |
| 140 | + { |
| 141 | + // We still have callbacks in the list so continue the async loop |
| 142 | + new Action(() => MonitorDataStream(interval, queue, list)).DelayAndExecute(interval); |
| 143 | + } |
| 144 | + else |
| 145 | + { |
| 146 | + lock (m_dataStreamMonitorActions) |
| 147 | + { |
| 148 | + // We are retiring this async loop so we need |
| 149 | + // to remove its queue from the lookup table |
| 150 | + m_dataStreamMonitorActions.TryRemove(interval, out queue); |
| 151 | + |
| 152 | + // However, actions may have been queued up in the meantime |
| 153 | + // so we need to re-register them with a new async loop |
| 154 | + while (queue.TryDequeue(out action)) |
| 155 | + RegisterDataStreamMonitor(interval, action); |
| 156 | + } |
| 157 | + } |
| 158 | + } |
| 159 | + |
| 160 | + #endregion |
| 161 | + |
| 162 | + #region [ Static ] |
| 163 | + |
| 164 | + // Static Fields |
| 165 | + |
| 166 | + /// <summary> |
| 167 | + /// Default instance of the <see cref="StaticTimer"/> class. |
| 168 | + /// </summary> |
| 169 | + public static readonly StaticTimer Default = new StaticTimer(); |
| 170 | + |
| 171 | + #endregion |
| 172 | + } |
| 173 | +} |