56 lines
1.4 KiB
C#
56 lines
1.4 KiB
C#
// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
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// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
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using System;
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using System.Collections.Generic;
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namespace ICSharpCode.AvalonEdit.Utils
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{
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/// <summary>
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/// This class is used to prevent stack overflows by representing a 'busy' flag
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/// that prevents reentrance when another call is running.
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/// However, using a simple 'bool busy' is not thread-safe, so we use a
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/// thread-static BusyManager.
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/// </summary>
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static class BusyManager
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{
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public struct BusyLock : IDisposable
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{
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public static readonly BusyLock Failed = new BusyLock(null);
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readonly List<object> objectList;
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public BusyLock(List<object> objectList)
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{
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this.objectList = objectList;
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}
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public bool Success {
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get { return objectList != null; }
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}
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public void Dispose()
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{
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if (objectList != null) {
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objectList.RemoveAt(objectList.Count - 1);
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}
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}
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}
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[ThreadStatic] static List<object> _activeObjects;
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public static BusyLock Enter(object obj)
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{
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List<object> activeObjects = _activeObjects;
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if (activeObjects == null)
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activeObjects = _activeObjects = new List<object>();
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for (int i = 0; i < activeObjects.Count; i++) {
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if (activeObjects[i] == obj)
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return BusyLock.Failed;
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}
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activeObjects.Add(obj);
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return new BusyLock(activeObjects);
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}
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}
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}
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