在挂起模式下创建的 Delphi 线程在 Windows 2012 服务器上自行启动

Question

过去几天我一直在为一个我无法理解的错误而苦苦挣扎。 这仅在 Windows 2012 服务器（64 位） 中发生，而（至少）在以下 Windows 版本上不会发生：Windows XP（32 位）、Windows 7（32 和 64 位）、Windows 8（64 位）、Windows 8.1（64 位）、Windows 10（64 位）、Windows 2003 Server（32 位）。

请注意，在所有情况下，应用程序都是 32 位二进制文​​件。

当应用程序启动时，它会初始化一些东西，最后它会创建一系列线程，所有线程都处于挂起模式，以便我以后可以手动启动它们。

在下面的代码中，可以预期 t 在睡眠后启动。 然而，当我尝试在线程上显式调用 Start 时，我意识到它已经（不知何故）已经启动，导致 线程已经启动异常（其中考虑到线程已经启动就可以了）。

// some initialization code is run before this, but nothing directly related
procedure foo;
var
  t : TThread; // note that there can be no reference to this thread from the outside since it's a local var
begin
  t := TMyThread.Create(true); // TMyThread

  sleep(3000); // time window of 3 seconds where the thread shouldn't have started

  t.Start; // now i want to start it manually, but the thread has already been started soon after it has been created
end;

常规（虚拟）匿名线程也会发生同样的情况，所以这不是 TMyThread 的错：

// some initialization code is run before this, but nothing directly related
procedure foo;
var
  t : TThread; // note that there can be no reference to this thread from the outside since it's a local var
begin
  t := TThread.CreateAnonymousThread( // to avoid using my possibly faulted TMyThread class, I'm now testing with a regular anonymous thread and the problem persists
    procedure begin 
      log('Hi from anon thread');
      sleep(5000); // to make it live 5 seconds for testing purposes
    end); 

  sleep(3000); // time window of 3 seconds where the thread shouldn't have started

  t.Start; // now i want to start it manually, but the thread has already been started soon after it has been created
end;

Windows 2012 服务器中是否存在一些我缺少的关于线程管理的机制？

日志摘录：

以下是健康日志文件的摘录。您可以看到 start 方法如何调用 startThreads 方法，该方法依次创建第一个线程。下一行表示从 CMP_AbstractThread 的构造函数进行的调用。 evInitialized 和 evStarted 是在 CMP_AbstractThread 的构造函数中创建的 TEvents。

12/03/2016 20:28:47.336: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMPPS_Application.start: start ...
12/03/2016 20:28:47.336: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMPPS_Application.createThreads: createThreads ...
12/03/2016 20:28:47.352: LOG_FINEST @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=0 (CMPP_EventsThread)).Create ...
12/03/2016 20:28:47.352: LOG_FINEST @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread)).Create.
12/03/2016 20:28:47.352: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread).evInitialized).Create ...
12/03/2016 20:28:47.352: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread).evInitialized).Create.
12/03/2016 20:28:47.352: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread).evInitialized).resetEvent ...
12/03/2016 20:28:47.352: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread).evInitialized).resetEvent.
12/03/2016 20:28:47.352: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread).evStarted).Create ...
12/03/2016 20:28:47.352: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread).evStarted).Create.
12/03/2016 20:28:47.352: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread).evStarted).resetEvent ...
12/03/2016 20:28:47.352: LOG_DEBUG  @ PID=5576 ThreadID=5188 (TExternalThread) @ CMP_AbstractThread.: (PID=5576 ThreadID=6084 (CMPP_EventsThread).evStarted).resetEvent.

以下是 Windows 2012 会话的摘录。您可以看到线程甚至在它自己的构造函数完成之前就开始了。来自线程 Execute 方法的日志行来自线程 5864，该线程仍在创建中。在这种特定情况下，异常甚至没有等待构造函数完成（通常是这样）。看起来好像 TThread 是用 False 而不是 True 创建的。

12/03/2016 20:29:31.813: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMPPS_Application.start: start ...
12/03/2016 20:29:31.813: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMPPS_Application.createThreads: createThreads ...
12/03/2016 20:29:31.813: LOG_FINEST @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=0 (CMPP_EventsThread)).Create ...
12/03/2016 20:29:31.813: LOG_FINEST @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread)).Create.
12/03/2016 20:29:31.813: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread).evInitialized).Create ...
12/03/2016 20:29:31.813: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread).evInitialized).Create.
12/03/2016 20:29:31.813: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread).evInitialized).resetEvent ...
12/03/2016 20:29:31.813: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread).evInitialized).resetEvent.

12/03/2016 20:29:31.813: LOG_FINEST @ PID=3796 ThreadID=5864 (CMPP_EventsThread) @ CMP_AbstractThread.Execute: (PID=3796 ThreadID=5864 (CMPP_EventsThread)) Executed.
12/03/2016 20:29:31.813: LOG_NORMAL @ PID=3796 ThreadID=5864 (CMPP_EventsThread) @ CMP_AbstractThread.Execute: (PID=3796 ThreadID=5864 (CMPP_EventsThread)) Down.

12/03/2016 20:29:31.828: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread).evStarted).Create ...
12/03/2016 20:29:31.828: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread).evStarted).Create.
12/03/2016 20:29:31.828: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread).evStarted).resetEvent ...
12/03/2016 20:29:31.828: LOG_DEBUG  @ PID=3796 ThreadID=4460 (TExternalThread) @ CMP_AbstractThread.: (PID=3796 ThreadID=5864 (CMPP_EventsThread).evStarted).resetEvent.

代码摘录：

constructor CMP_AbstractThread.Create(suspended : boolean);
begin
  inherited Create(suspended); // this one sets up threadName
  FEvInitialized := CMP_Event.Create(threadName, 'evInitialized');
  FEvInitialized.ResetEvent;
  FEvStarted := CMP_Event.Create(threadName, 'evStarted');
  FEvStarted.ResetEvent;
end;

Constructor CMP_Thread.Create(suspended : boolean);
Begin
  log(LOG_FINEST, format('(%s).Create ...', [ThreadInfo]));
  inherited Create(suspended);
  FThreadName := threadInfo;
  log(LOG_FINEST, format('(%s).Create.', [ThreadName]));
End;

procedure CMPPS_Application.createThreads;
begin
  logGuard('createThreads', procedure begin
    FEventsThread := CMPP_EventsThread(CMPP_EventsThread.Create(true)
      .setDbConnection(FDB)
      .setLogger(GEventsLogger)
      .setDelay(MP_EVENTS_THREAD_DELAY));
  end);
end;

CMPP_EventsThread = class(CMPC_EventsThread)
  // all the following methods are inherited from different layers
  // Create(boolean) is inherited directly from CMP_AbstractThread
  // setDbConnection(IMP_DBConnection)
  // setLogger(IMP_Logger)
  // setDelay(integer)
end;

Answer 1

您所描述的在正常情况下是相当不可能的。如果TThread 构造函数的ACreateSuspended 参数为True，则线程创建为挂起状态。没有如果，ands，或buts about that。暂停的线程不能自发启动。

匿名线程总是被创建为挂起的。

假设您在有效的TThread 对象上调用TThread.Start()，Start()仅在以下任一情况下引发异常：

1. FCreateSuspended 成员为 False。如果ACreateSuspended 参数为True，则此成员在TThread 构造函数中设置为True，并由Start() 设置为False。您只能拨打一次Start()。

2. FFinished 成员为 True。在调用TThread.Execute() 和TThread.DoTerminate() 后，该值设置为True，这意味着线程已经运行完成。你不能在终止的线程上调用Start()。

3. FExternalThread 成员为 True。这是为TThread.GetCurrentThread() 返回的TThread 对象设置的。你不能在你没有明确Create()的线程上调用Start()。

4. 以上条件都可以，但是底层OS线程（由TThread.Handle属性表示）没有成功从挂起状态转换到运行状态。 唯一可能发生的方式是，如果您的代码中的某些内容正在调用 TThread.Suspend() 或 TThread.Resume()（或者更糟糕的是，某些内容正在直接调用 Win32 API SuspendThread() 或 ResumeThread()）来更改在您调用 TThread.Start() 之前线程的暂停计数。

鉴于您展示的示例代码，这些条件是不可能的。所以问题必须与你没有显示的代码有关。