Source code for the article "Tudo ao mesmo tempo agora com C#" originally published at https://medium.com/pricefy-labs

parallel_foreach.cs

private static void ParallelForEach()
{
    var numberOfIterations = 1000;

    var min = 0;
    var max = 100_000_000;

    // Will cancel the operation on a random time basis; it might complete sometimes
    // depending on the host machine
    var timeInMs = 0;
    var cts = new CancellationTokenSource();
    Task.Run(async () =>
    {
        timeInMs = new Random().Next(100, 1000);
        await Task.Delay(timeInMs);

        Console.WriteLine($"- Will cancel after {timeInMs} ms <-----------");
        cts.Cancel();
    });

    Console.WriteLine($"Generating random numbers from {min} to {max} over {numberOfIterations} iterations");

    try
    {
        Parallel.ForEach(
            GenerateRandomNumbers(numberOfIterations, min, max),
            new ParallelOptions
            {
                CancellationToken = cts.Token,
                //MaxDegreeOfParallelism = 100 // <-- you can play with this number to get a grasp of how this works;
                //                             //     essentially, the max viable degree of parallelism is the number
                //                             //     of cores available; try a few numbers and watch it for time to
                //                             //     complete the work
            },
            (num, state, i) =>
            {
                Console.WriteLine($"- Iteration #{i} > Begin at thread #{Thread.CurrentThread.ManagedThreadId}, task #{Task.CurrentId}");
                Console.WriteLine($"- Iteration #{i} > End: {num}");
            });
    }
    catch (OperationCanceledException)
    {
        Console.WriteLine($"Parallel task was canceled by a CancellationToken after {timeInMs} ms");
    }
}