Observe cancellation through a token.

C#: A cancellation token is cooperative; operations must check it or accept it as an argument.

using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.Json;
using System.Text.RegularExpressions;
using System.Collections.Generic;
using System.Globalization;
using System.Security.Cryptography;
using System.Threading;
using System.Threading.Tasks;

using var source = new CancellationTokenSource();
source.Cancel();
try { source.Token.ThrowIfCancellationRequested(); }
catch (OperationCanceledException) { Console.WriteLine("Canceled"); }

Expected output EXAMPLE

Canceled

Details

Use Program.cs in a .NET 8 console project and run dotnet run. Uses only the .NET standard libraries. A cancellation token is cooperative; operations must check it or accept it as an argument.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · 2026-11-02 18:07:56 UTC · 8.0.425 · libc6 2.39-0ubuntu8.9

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel: x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale: uid=65534, gid=65534 (unprivileged) / C.UTF-8
Interpreter invocation: dotnet build --no-restore && dotnet out/csharp.dll
Container image ID: sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd
Code SHA-256: 3548b24b7c26bb62f7ff8c7aacd747b0b6a6a4369471a5800e49ad50ad52ef17
Dependencies: libc6 2.39-0ubuntu8.9

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

Canceled

Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.