c# - 如果我没有完成ActionBlock会不会有问题

Question

我正在尝试使用操作块来执行一些任务。我的问题是什么时候CreateActionBlock()方法结束，ActionBlock仍在处理数据。由于该方法已返回并且我无法调用 actionBlock.Complete() .如果我运行这个 CreateActionBlock() 会不会引起任何问题？千次？内存中会永远有数千个 actionBlocks 还是在处理 5 个输入后会被 GC 处理？

private static async Task Dequeue(string content)
{
    Console.WriteLine("The string is " + content);
    await Task.Delay(10000);
}

public static void CreateActionBlock()
{
    var actionBlock = new ActionBlock<string>(
        (e) => Dequeue(e),
        new ExecutionDataflowBlockOptions()
        {
            BoundedCapacity = 5,
            MaxDegreeOfParallelism = 1
        });

    for (int i = 0; i < 5; i++)
    {
        actionBlock.Post(i.ToString());
    }
}

Answer 1

一旦数据流块的输入队列被清空，并且当前处于空闲状态，它就有资格进行垃圾回收。下面是一个演示此行为的示例:

var weakReference = InnerMethod();
for (int i = 1; i <= 10; i++)
{
    Thread.Sleep(100);
    GC.Collect();
    Console.WriteLine($"IsAlive: {weakReference.IsAlive}");
}

WeakReference InnerMethod()
{
    var block = new ActionBlock<int>(n =>
    {
        Thread.Sleep(200);
        Console.WriteLine($"Processed: {n}");
    });
    block.Post(1); block.Post(2); block.Post(3);
    return new WeakReference(block);
}

输出:

IsAlive: True
Processed: 1
IsAlive: True
IsAlive: True
Processed: 2
IsAlive: True
IsAlive: True
Processed: 3
IsAlive: False
IsAlive: False
IsAlive: False
IsAlive: False
IsAlive: False

( Try it on Fiddle )