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

parallel_for.cs

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

    var min = 0;
    var max = 100_000_000;

    var random = new Random();
    var breakIndex = random.Next(1, numberOfIterations);

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

    var result = Parallel.For(1, numberOfIterations, (i, state) =>
    {
        Console.WriteLine($"- Iteration #{i} > Begin at thread #{Thread.CurrentThread.ManagedThreadId}, task #{Task.CurrentId}");

        // Has .Break() been called by another parallel iteration?
        if (state.ShouldExitCurrentIteration)
        {
            // Is this current iteration greater then the one where .Break() was invoked?
            if (state.LowestBreakIteration < i)
            {
                Console.WriteLine($"- Iteration #{i} > Will exit now <-----------");
                return;
            }
        }

        int num;

        // A naive lock for educative purpose only
        lock (random)
        {
            num = random.Next(min, max);
        }

        // If it got to the break index, invokes .Break() to prevent further iterations
        if (i == breakIndex)
        {
            Console.WriteLine($"- Iteration #{i} > Got to break index <-----------");
            state.Break();
        }

        Console.WriteLine($"- Iteration #{i} > End: {num}");
    });

    if (result.LowestBreakIteration.HasValue)
        Console.WriteLine($"Lowest break iteration? {result.LowestBreakIteration}");
}