Wrapper to run a task with a custom timeout time and a cancellation token to be triggered if the time ends.

TaskWithTimeoutWrapper.cs

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

namespace MyNamespace
{
    public class TaskWithTimeoutWrapper
	{
        protected volatile bool taskFinished = false;

        public async Task<T> RunWithCustomTimeoutAsync<T>(int millisecondsToTimeout, Func<Task<T>> taskFunc, CancellationTokenSource cancellationTokenSource = null)
		{
			this.taskFinished = false;

			var results = await Task.WhenAll<T>(new List<Task<T>>
			{
                this.RunTaskFuncWrappedAsync<T>(taskFunc),
				this.DelayToTimeoutAsync<T>(millisecondsToTimeout, cancellationTokenSource)
			});

			return results[0];
		}

        public async Task RunWithCustomTimeoutAsync(int millisecondsToTimeout, Func<Task> taskFunc, CancellationTokenSource cancellationTokenSource = null)
		{
            this.taskFinished = false;

			await Task.WhenAll(new List<Task>
			{
				this.RunTaskFuncWrappedAsync(taskFunc),
				this.DelayToTimeoutAsync(millisecondsToTimeout, cancellationTokenSource)
			});
		}

        protected async Task DelayToTimeoutAsync(int millisecondsToTimeout, CancellationTokenSource cancellationTokenSource)
		{
			await Task.Delay(millisecondsToTimeout);

            this.ActionOnTimeout(cancellationTokenSource);
		}

		protected async Task<T> DelayToTimeoutAsync<T>(int millisecondsToTimeout, CancellationTokenSource cancellationTokenSource)
		{
            await this.DelayToTimeoutAsync(millisecondsToTimeout, cancellationTokenSource);

			return default(T);
		}

        protected virtual void ActionOnTimeout(CancellationTokenSource cancellationTokenSource)
        {
			if (!this.taskFinished)
			{
				cancellationTokenSource?.Cancel();
				throw new Exception();
			}
        }

        protected async Task RunTaskFuncWrappedAsync(Func<Task> taskFunc)
		{
			await taskFunc.Invoke();

			this.taskFinished = true;
		}

        protected async Task<T> RunTaskFuncWrappedAsync<T>(Func<Task<T>> taskFunc)
		{
			var result = await taskFunc.Invoke();

			this.taskFinished = true;

			return result;
		}
	}
}