Multithreading 在挂起模式下创建的Delphi线程在windows 2012服务器上自行启动
过去几天我一直在为一个我不理解的bug而挣扎。 这仅在Windows 2012服务器(64位)中发生,而在以下Windows版本中(至少)不会发生: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服务器(32位) 请注意,应用程序在所有情况下都是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,我们希望在睡眠后启动t。 然而,当我尝试显式地调用线程的Start时,我意识到它已经启动了(不知何故),导致了一个线程已经启动异常(考虑到线程已经启动,这是可以的) 常规(虚拟)匿名线程也会发生同样的情况,因此这不是TMyThread的错:Multithreading 在挂起模式下创建的Delphi线程在windows 2012服务器上自行启动,multithreading,delphi,delphi-xe,windows-server-2012,delphi-10-seattle,Multithreading,Delphi,Delphi Xe,Windows Server 2012,Delphi 10 Seattle,过去几天我一直在为一个我不理解的bug而挣扎。 这仅在Windows 2012服务器(64位)中发生,而在以下Windows版本中(至少)不会发生: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服务器(32位) 请注意,应用程序在所有情况下都是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
// 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 server中是否存在我所缺少的线程管理机制
日志摘录:
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;
以下是一个健康日志文件的摘录。您可以看到start方法如何调用startThreads方法,后者依次创建第一个线程。接下来的几行表示从CMP_AbstractThread的构造函数发出的调用。evInitialized和evStarted是在CMP_AbstractThread的构造函数中创建的事件
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自己的构造函数完成之前就启动了。来自threads Execute方法的日志行来自仍在创建的线程5864。在这种特定的情况下,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;
你所描述的在正常情况下是不可能的。如果
TThread
构造函数的ACreateSuspended
参数为True,则线程将在挂起状态下创建。关于那件事,没有如果,和,但是。挂起的线程无法自动启动
匿名线程的创建总是挂起的
假设您正在对有效的TThread
对象调用TThread.Start()
,Start()
仅在以下情况下引发异常:
FCreateSuspended
成员为False。如果ACreateSuspended
参数为True,则在TThread
构造函数中将此成员设置为True,并通过Start()
将其设置为False。只能调用一次Start()
FFinished
成员为True。在调用TThread.Execute()
和TThread.DoTerminate()
后,这将设置为True,这意味着线程一直在运行到完成。不能在终止的线程上调用Start()
FExternalThread
成员为True。这是为TThread.GetCurrentThread()
返回的TThread
对象设置的。不能在未显式创建()的线程上调用Start()
TThread.Handle
属性表示)未成功从挂起状态转换为运行状态。唯一可能发生的方法是,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或直接调用),以在调用TThread.Start()
之前更改线程的挂起计数根据您展示的示例代码,这些条件是不可能的。因此,问题必须与您未显示的代码有关。您所描述的内容在正常情况下是不可能的。如果
TThread
构造函数的ACreateSuspended
参数为True,则线程将在挂起状态下创建。关于那件事,没有如果,和,但是。挂起的线程无法自动启动
匿名线程的创建总是挂起的
假设您正在对有效的TThread
对象调用TThread.Start()
,Start()
仅在以下情况下引发异常:
FCreateSuspended
成员为False。如果ACreateSuspended
参数为True,则在TThread
构造函数中将此成员设置为True,并通过Start()
将其设置为False。只能调用一次Start()
FFinished
成员为True。在调用TThread.Execute()
和TThread.DoTerminate()
后,这将设置为True,这意味着线程一直在运行到完成。不能在终止的线程上调用Start()
FExternalThread
成员为True。这是为TThread.GetCurrentThread()
返回的TThread
对象设置的。不能在未显式创建()的线程上调用Start()
TThread.Handle
属性表示)未成功从挂起状态转换为运行状态。唯一可能发生的方法是,如果代码中的某些内容正在调用TThread.Suspend()
或TThread.Resume()
(或者更糟的是,某些内容正在调用Win32 API或直接调用)来更改线程的挂起计数