Question

以下是我的代码：

static int Main(string[] args)
{
    Thread current_thread = Thread.CurrentThread;

    new Thread(() => { var i = 0; while (++i > 0) { Thread.Sleep(100); Console.WriteLine("Thread: " + current_thread.ManagedThreadId + ", State: " + current_thread.ThreadState + ", I: " + i); } }).Start();

    while(true)
    {
        Console.WriteLine("Thread: " + Thread.CurrentThread.ManagedThreadId + ", State: " + Thread.CurrentThread.ThreadState);

        // creating a http request...
        // ...
        requst.GetResponseStream(); // this is the synchronous call 
    }
}

输出显示当前线程（主线程）的状态始终为ThreadState.Running。所以，为什么，为什么不是ThreadState.WaitSleepJoin？

GetResponseStream()是同步的。在等待远程响应时，cpu时间片可以（并且应该）放弃到其他线程，对吧？（如果我错了，请纠正我）

非常感谢你。

Answer 1

是的，它是WaitSleepJoin。您的示例代码显然是不完整和错误的（例如，您没有启动新主题），因此不容易说出为什么您没有看到正确的值。您是否始终为GetResponseStream创建新请求？

此代码显示了您的预期：

Thread current_thread = Thread.CurrentThread;

new Thread(() => 
{ 
  var i = 0; while (++i > 0) 
  { 
    if ((current_thread.ThreadState & System.Threading.ThreadState.WaitSleepJoin) > 0) 
      Console.WriteLine("Thread: " + current_thread.ManagedThreadId 
       + ", State: " + current_thread.ThreadState + ", I: " + i); 
  } 
}
).Start();

while(true)
{
    Console.WriteLine("Thread: " + Thread.CurrentThread.ManagedThreadId 
      + ", State: " + Thread.CurrentThread.ThreadState);

    var request = HttpWebRequest.CreateHttp("http://www.google.com/");

    using (var response = request.GetResponse())
    {
        using (var stream = response.GetResponseStream())
        {
            stream.Read(new byte[2048], 0, 2048);
        }
    } 
}

棘手的部分是它没有花费大量时间在WaitSleepJoin州。

当发出同步I / O调用时，当前线程（C＃）的ThreadState是什么？

1 个答案: