// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace Microsoft.CodeAnalysis.Remote;
 
internal static class CancellationTokenSourceExtensions
{
    /// <summary>
    /// Automatically cancels the <paramref name="cancellationTokenSource"/> if the input <paramref name="task"/>
    /// completes in a <see cref="TaskStatus.Canceled"/> or <see cref="TaskStatus.Faulted"/> state.
    /// </summary>
    /// <param name="cancellationTokenSource">The cancellation token source.</param>
    /// <param name="task">The task to monitor.</param>
    public static void CancelOnAbnormalCompletion(this CancellationTokenSource cancellationTokenSource, Task task)
    {
        if (cancellationTokenSource is null)
            throw new ArgumentNullException(nameof(cancellationTokenSource));
 
        _ = task.ContinueWith(
            static (_, state) =>
            {
                try
                {
                    ((CancellationTokenSource)state!).Cancel();
                }
                catch (ObjectDisposedException)
                {
                    // cancellation source is already disposed
                }
            },
            state: cancellationTokenSource,
            CancellationToken.None,
            TaskContinuationOptions.NotOnRanToCompletion | TaskContinuationOptions.ExecuteSynchronously,
            TaskScheduler.Default);
    }
}