相关疑难解决方法(0)

假设我有一个IO绑定任务.我使用WithDegreeOfParallelism = 10和WithExecution = ForceParallelism模式,但查询仍然只使用两个线程.为什么？

我知道PLINQ通常会选择一个与我的核心数相等的并行度,但为什么它忽略了我对更高并行性的特定要求呢？

static void Main(string[] args)
{
    TestParallel(0.UpTo(8));
}

private static void TestParallel(IEnumerable<int> input)
{
    var timer = new Stopwatch();
    timer.Start();
    var size = input.Count();

    if (input.AsParallel().
        WithDegreeOfParallelism(10).
        WithExecutionMode(ParallelExecutionMode.ForceParallelism).
        Where(IsOdd).Count() != size / 2)
        throw new Exception("Failed to count the odds");

    timer.Stop();
    Console.WriteLine("Tested " + size + " numbers in " + timer.Elapsed.TotalSeconds + " seconds");
}

private static bool IsOdd(int n)
{
    Thread.Sleep(1000);
    return n%2 == 1;
}