36 lines
1.4 KiB
C#
36 lines
1.4 KiB
C#
// Licensed to the .NET Foundation under one or more agreements.
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// The .NET Foundation licenses this file to you under the MIT License.
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// See the LICENSE file in the project root for more information.
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using System.IO;
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using System.Threading;
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namespace System.Reactive
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{
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/// <summary>
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/// Utility methods to handle lock-free combining of Exceptions
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/// as well as hosting a terminal-exception indicator for
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/// lock-free termination support.
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/// </summary>
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internal static class ExceptionHelper
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{
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/// <summary>
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/// The singleton instance of the exception indicating a terminal state,
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/// DO NOT LEAK or signal this via OnError!
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/// </summary>
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public static Exception Terminated { get; } = new EndOfStreamException("On[Error|Completed]");
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/// <summary>
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/// Tries to atomically set the Exception on the given field if it is
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/// still null.
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/// </summary>
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/// <param name="field">The target field to try to set atomically.</param>
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/// <param name="ex">The exception to set, not null (not verified).</param>
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/// <returns>True if the operation succeeded, false if the target was not null.</returns>
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public static bool TrySetException(ref Exception? field, Exception ex)
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{
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return Interlocked.CompareExchange(ref field, ex, null) == null;
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}
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}
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}
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