TCC 11.00.39 hangs on startup

[Patulus]

Sometimes TCC silently hangs on startup. Process Explorer shows some minor activity in some worker threads, that's all. Process Monitor shows that TCC hanged after starting a couple of threads. It hangs even with /IS option. And before actually even start to execute the command file passed as a parameter.

 

[rconn]

> Sometimes TCC silently hangs on startup. Process Explorer shows some
> minor activity in some worker threads, that's all. Process Monitor
> shows that TCC hanged after starting a couple of threads. It hangs even
> with /IS option. And before actually even start to execute the command
> file passed as a parameter.

Those are not TCC threads. I would guess that another process is injecting
a dll and/or remote threads into the TCC process. Check your system for
things like anti-virus apps and display monitors, and try disabling them to
see where the problem is coming from.

Rex Conn
JP Software

 

[Patulus]

Those are not TCC threads.

Hello Rex,

Yes, it is possible, since I see some InitUserApiHook in the stack trace. I'll try to investigate it more closely.

But... I have a question, Rex. Whatever hooks I have in my system, they do not cause any problems with other applications. The only reason of hangs connected with hooks I see is the not-so-well-known bug in the Windows x64 kernel, which limits drastically recursion depth of SendMessage in a case when there are some hooks set on message queue. So the question is: do you use SendMessage recursion extensively in TCMD?

Patulus.

 

[rconn]

> Yes, it is possible, since I see some InitUserApiHook in the stack
> trace. I'll try to investigate it more closely.
>
> But... I have a question, Rex. Whatever hooks I have in my system, they
> do not cause any problems with other applications. The only reason of
> hangs connected with hooks I see is the not-so-well-known bug in the
> Windows x64 kernel, which limits drastically recursion depth of
> SendMessage in a case when there are some hooks set on message queue.
> So the question is: do you use SendMessage recursion extensively in
> TCMD?

No.

But Take Command is an unusual combination of a GUI and console app, and
I've seen problems with poorly written injection code in the past.

Rex Conn
JP Software

 

[Patulus]

I have found the culprit. This is WindowBlinds by Stardoc.

 

[Patulus]

I created a thread in the WindowBlinds forum about the issue http://forums.stardock.com/375234 .