Question

我将实现一个任务池，其中最多应该有console.log(characters);个在paralell中运行的任务。

新作业可以从任何线程进入，并使用下一个免费任务。如果没有可用的任务，则应等待一个任务释放。完成所有工作后，任务应“休眠”以不占用CPU时间。

在C＃/ .NET中是否已经有类似的东西？

谢谢！

Answer 1

我将看一下TPL Dataflow Library中的Action块，这些块将为您提供所需的功能。在您指定的甚至更复杂的需求的生产环境中，我一直使用它。

Answer 2

您可以轻松使用ConcurrentExclusiveSchedulerPair。这是示例代码：

// max 3 parallel tasks
var schedulerPair = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 3);
var factory = new TaskFactory(schedulerPair.ConcurrentScheduler);

应使用following code开始新的Task：

factory.StartNew(() => create task here).Unwrap()

完整示例：

static async Task Main(string[] args)
{
    var schedulerPair = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, 3);
    var factory = new TaskFactory(schedulerPair.ConcurrentScheduler);
    var tasks = new List<Task>();
    Random r = new Random();
    for (int i = 0; i < 5; i++)
    {
        var localI = i;
        var ts = TimeSpan.FromMilliseconds(1000 + r.Next(0, 10) * 100);
        var task = factory.StartNew(() => RunTask(localI, ts)).Unwrap();
        tasks.Add(task);
    }
    await Task.WhenAll(tasks);
}

static object mutex = new object();
static int numberOfParallelWorkers;

static async Task RunTask(int n, TimeSpan delay)
{
    for (int i = 0; i < 2; i++)
    {
        int nw;
        lock (mutex) { nw = numberOfParallelWorkers = numberOfParallelWorkers + 1; }
        var start = DateTime.Now;
        Console.WriteLine($"Started task #{n} part {i} at {start:ss.ff}, tasks: {nw}");
        Thread.Sleep(delay); // simulate CPU-bound work
        lock (mutex) { nw = numberOfParallelWorkers = numberOfParallelWorkers - 1; }
        var end = DateTime.Now;
        Console.WriteLine($"Finished task #{n} part {i} at {end:ss.ff}, parallel: {nw}");
    }
    await Task.Yield();
}

产生以下输出：

Started task #1 part 0 at 43.98, parallel: 2
Started task #0 part 0 at 43.98, parallel: 1
Started task #2 part 0 at 43.98, parallel: 3
Finished task #0 part 0 at 45.09, parallel: 2
Started task #0 part 1 at 45.09, parallel: 3
Finished task #1 part 0 at 45.29, parallel: 2
Started task #1 part 1 at 45.29, parallel: 3
Finished task #2 part 0 at 45.59, parallel: 2
Started task #2 part 1 at 45.59, parallel: 3
Finished task #0 part 1 at 46.19, parallel: 2
Started task #3 part 0 at 46.19, parallel: 3
Finished task #1 part 1 at 46.59, parallel: 2
Started task #4 part 0 at 46.59, parallel: 3
Finished task #2 part 1 at 47.19, parallel: 2
Finished task #4 part 0 at 47.59, parallel: 1
Started task #4 part 1 at 47.59, parallel: 2
Finished task #3 part 0 at 47.69, parallel: 1
Started task #3 part 1 at 47.69, parallel: 2
Finished task #4 part 1 at 48.59, parallel: 1
Finished task #3 part 1 at 49.19, parallel: 0

是否存在TaskPool参考实现？

2 个答案: