TimeoutHandler.cs

using System;
using System.Threading;
using System.Threading.Tasks;

namespace Open.Threading.Tasks;

public sealed class TimeoutHandler : IDisposable
{
	CancellationTokenSource? _tokenSource;

	TimeoutHandler(TimeSpan delay, Action<TimeSpan> onTimeout)
	{
		_tokenSource = new CancellationTokenSource();
		Task.Delay(delay, _tokenSource.Token).ContinueWith(t =>
		{
			Interlocked.Exchange(ref _tokenSource, null!)?.Dispose();
			if (!t.IsCanceled) onTimeout(delay);
		});
	}

	public static TimeoutHandler New(TimeSpan delay, Action<TimeSpan> onTimeout) => new(delay, onTimeout);

	public static bool New(TimeSpan delay, out IDisposable timeout, Action<TimeSpan> onTimeout)
	{
		timeout = New(delay, onTimeout);
		return true;
	}

	public static TimeoutHandler New(double delay, Action<double> onTimeout) => New(TimeSpan.FromMilliseconds(delay), ts => onTimeout(ts.TotalMilliseconds));

	public static bool New(double delay, out IDisposable timeout, Action<double> onTimeout)
	{
		timeout = New(delay, onTimeout);
		return true;
	}

	public void Dispose()
	{
		var ts = Interlocked.Exchange(ref _tokenSource, null);
		if (ts is null) return;
		ts.Cancel();
		ts.Dispose();
	}
}