CancellationTokenSource

Context: CancellationTokenSource is used to create a CancellationToken and to request cancellation by calling Cancel().

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

public class TimeoutExample
{
    public static async Task Main()
    {
        using var cts = new CancellationTokenSource();
        cts.CancelAfter(5000); // auto‑cancel after 5 seconds

        // Request cancellation manually (e.g., user press)
        // cts.Cancel();

        try
        {
            await LongRunningOperationAsync(cts.Token);
        }
        catch (OperationCanceledException)
        {
            Console.WriteLine("Operation cancelled");
        }
    }

    static async Task LongRunningOperationAsync(CancellationToken token)
    {
        for (int i = 0; i < 100; i++)
        {
            token.ThrowIfCancellationRequested();
            await Task.Delay(100);
        }
    }
}

Obtaining a token

CancellationToken token = cts.Token;

Real-world usage example

Timeout for HTTP requests: Use CancellationTokenSource with CancelAfter to set a timeout.

Example: HttpClient with cancellation

CancellationTokenSource

Obtaining a token

Real-world usage example

Related sections