Question

在过去的几天里，我一直在努力解决一个我无法理解的错误。这仅发生在 Windows 2012服务器（64位），而在以下Windows版本中不会发生（至少）：Windows XP（32位），Windows 7（32位和64位），Windows 8（64位），Windows 8.1（64位），Windows 10（64位），Windows 2003 Server（32位）。

请注意，所有情况下的应用程序都是32位二进制文件。

当应用程序启动时，它初始化一些东西，最后它创建了一系列线程，所有这些线程都处于挂起模式，以便我可以在以后手动启动它们。

在以下代码中，可以预期在睡眠后启动 t 。但是，当我尝试在线程上显式调用Start时，我意识到它已经启动（不知何故），导致 线程已经启动异常 （其中考虑到线程已经启动，可以。）

// 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;

对于常规（虚拟）匿名线程也会发生同样的情况，因此它不会是TMyThread的错误：

// 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线程管理机制？

日志EXCERPTS ：

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。下一行代表从CMP_AbstractThread的构造函数调用。 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。你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，即仍在创建的线程。在这种特定情况下，异常甚至不等待构造函数完成（通常是这样）。似乎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EXCERPTS ：

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

在正常情况下，你所描述的是相当不可能的。如果ACreateSuspended构造函数的TThread参数为True，则以挂起状态创建线程。没有ifs，ands或buts。悬浮的线程不能自发地开始。

始终会创建匿名线程暂停。

假设您在有效的TThread.Start()对象上呼叫TThread，Start()会引发异常，如果是：

FCreateSuspended成员为False。如果TThread参数为True，则此成员在ACreateSuspended构造函数中设置为True，并由Start()设置为False。您只能拨打Start()一次。
FFinished成员为True。在TThread.Execute()和TThread.DoTerminate()被调用后，此值设置为True，表示该线程已运行完成。您无法在已终止的主题上调用Start()。
FExternalThread成员为True。这是为TThread返回的TThread.GetCurrentThread()对象设置的。您无法在未明确Start()的帖子上调用Create()。
上述条件没问题，但底层操作系统线程（由TThread.Handle属性表示）未成功从挂起状态转换为运行状态。如果代码中的某些内容正在调用TThread.Suspend()或TThread.Resume()（或者更糟糕的是，某些内容正在调用Win32 API SuspendThread()或{{}，则可能会出现唯一方式3}}直接）在你打电话TThread.Start()之前改变线程的暂停计数。

根据您显示的示例代码，这些条件是不可能的。所以问题必须与你没有展示的代码有关。

在挂起模式下创建的Delphi线程在Windows 2012服务器

1 个答案: