83 lines
2.4 KiB
C#
83 lines
2.4 KiB
C#
// <copyright>
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// Copyright (c) Microsoft Corporation. All rights reserved.
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// </copyright>
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namespace System.Runtime
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{
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using System;
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using System.Threading;
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class IOThreadCancellationTokenSource : IDisposable
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{
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static readonly Action<object> onCancel = Fx.ThunkCallback<object>(OnCancel);
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readonly TimeSpan timeout;
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CancellationTokenSource source;
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CancellationToken? token;
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IOThreadTimer timer;
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public IOThreadCancellationTokenSource(TimeSpan timeout)
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{
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TimeoutHelper.ThrowIfNegativeArgument(timeout);
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this.timeout = timeout;
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}
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public IOThreadCancellationTokenSource(int timeout)
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: this(TimeSpan.FromMilliseconds(timeout))
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{
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}
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// NOTE: this property is NOT threadsafe. Potential race condition could be caused if you are accessing it
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// via different threads.
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public CancellationToken Token
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{
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get
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{
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if (this.token == null)
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{
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if (this.timeout >= TimeoutHelper.MaxWait)
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{
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this.token = CancellationToken.None;
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}
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else
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{
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this.timer = new IOThreadTimer(onCancel, this, true);
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this.source = new CancellationTokenSource();
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this.timer.Set(this.timeout);
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this.token = this.source.Token;
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}
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}
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return this.token.Value;
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}
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}
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public void Dispose()
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{
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if (this.source != null)
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{
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Fx.Assert(this.timer != null, "timer should not be null.");
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if (this.timer.Cancel())
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{
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this.source.Dispose();
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this.source = null;
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}
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}
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}
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static void OnCancel(object obj)
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{
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Fx.Assert(obj != null, "obj should not be null.");
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IOThreadCancellationTokenSource thisPtr = (IOThreadCancellationTokenSource)obj;
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thisPtr.Cancel();
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}
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void Cancel()
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{
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Fx.Assert(this.source != null, "source should not be null.");
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this.source.Cancel();
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this.source.Dispose();
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this.source = null;
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}
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}
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}
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