using System;

using System.Threading;

using System.Threading.Tasks;

​

/**

Problem Statement:

Implement the missing part of the PerformLongRunningTaskAsync method using TaskCompletionSource methods, 

in combination with the CancellationToken received in the function.

**/

​

namespace Synchronization

{

    internal class Program

    {

        static void Main(string[] args)

        {

            var cancellationTokenSource = new CancellationTokenSource();

            cancellationTokenSource.CancelAfter(TimeSpan.FromSeconds(3));

            Task<string> task = PerformLongRunningTaskAsync(cancellationTokenSource.Token);

​

            try

            {

                Console.WriteLine("Waiting for the task to complete...");

                string result = task.GetAwaiter().GetResult();

                Console.WriteLine($"Task result: {result}");

            }

            catch (TaskCanceledException)

            {

                Console.WriteLine("Task was canceled.");

            }

            finally

            {

                Console.ReadLine();

            }

        }

​

        private static async Task<string> PerformLongRunningTaskAsync(CancellationToken cancellationToken)

        {

            var taskCompletionSource = new TaskCompletionSource<string>();

​

            await Task.Delay(5000);

​

            return await taskCompletionSource.Task;

        }

    }

}

​