在ActionBlock中收集结果时阻止收集

时间:2018-01-19 09:21:51

标签: c# task-parallel-library tpl-dataflow

我认为在测试方法中,“results”集合变量必须是BlockingCollection<int>类型而不是List<int>。如果我错了,请向我证明。我从https://blog.stephencleary.com/2012/11/async-producerconsumer-queue-using.html

中采用了这个例子
private static async Task Produce(BufferBlock<int> queue, IEnumerable<int> values)
{
    foreach (var value in values)
    {
        await queue.SendAsync(value);
    }
}

public async Task ProduceAll(BufferBlock<int> queue)
{
    var producer1 = Produce(queue, Enumerable.Range(0, 10));
    var producer2 = Produce(queue, Enumerable.Range(10, 10));
    var producer3 = Produce(queue, Enumerable.Range(20, 10));
    await Task.WhenAll(producer1, producer2, producer3);
    queue.Complete();
}

[TestMethod]
public async Task ConsumerReceivesCorrectValues()
{
    var results = new List<int>();

    // Define the mesh.
    var queue = new BufferBlock<int>(new DataflowBlockOptions { BoundedCapacity = 5, });

    //var consumerOptions = new ExecutionDataflowBlockOptions { BoundedCapacity = 1, };

    var consumer = new ActionBlock<int>(x => results.Add(x), consumerOptions);
    queue.LinkTo(consumer, new DataflowLinkOptions { PropagateCompletion = true, });

    // Start the producers.
    var producers = ProduceAll(queue);

    // Wait for everything to complete.
    await Task.WhenAll(producers, consumer.Completion);

    // Ensure the consumer got what the producer sent.
    Assert.IsTrue(results.OrderBy(x => x).SequenceEqual(Enumerable.Range(0, 30)));
}

1 个答案:

答案 0 :(得分:4)

由于<div class="box-container"> <div class="box"> foo<br>foo<br>foo </div> <div class="box"> foo<br>foo </div> <div class="box"> foo </div> </div> 默认情况下将其委托限制为一次执行一次(ActionBlock<T> MaxDegreeOfParallelism),因此无需使用1代替BlockingCollection<T>

正如预期的那样,代码中的测试对我来说很合适。

如果List<T>通过了ActionBlock<T>更高的选项,那么您需要保护MaxDegreeOfParallelism或将其替换为List<T>