Question on using winedbg when program does not crash, just becomes unresponsive

[Eric Pouech]

Peter Urbanec a écrit :
>
> Dan Kegel wrote:
>>   start winedbg without any app
>>   say 'bt all' in winedbg
>> Voila, you now have backtraces for every process, including the hung 
>> one.
>> It's your job to get that into a text file and remove the 
>> uninteresting ones...
>
>
> I've also been trying to debug a multithreaded app. There are at least 
> two complications that winedbg throws up:
>
> 1. Is now documented in http://bugs.winehq.org/show_bug.cgi?id=20617
>
> 2. As far as I can tell, winedbg will not allow you to switch the 
> current thread context. This means that even though you can get a 
> backtrace of all threads in all processes, you actually can not 
> examine the state of a specific thread.
>
> I don't know enough about the internals of wine to go ahead and 
> implement a "thread tid" command. I could manage the code in dbg.y and 
> debug.l to implement the command line interface. When it comes to the 
> actual implementation, I can sort of guess at what may need to be done 
> there. However, I suspect that my naive attempts at an implementation 
> are unlikely to produce an acceptable patch.
>
> It can't be as simple as updating the value of dbg_curr_thread with 
> the result of dbg_get_thread(dbg_curr_process, tid) and then calling 
> GetThreadContext(dbg_curr_thread->handle, &dbg_context), can it?
>
the changes will need to be larger than that
winedbg assumes throughout the code that it's stopped in a single thread
but, if you change dbg_curr_thread, and enter the 'cont' command, you 
have to decide which thread should be resumed
therefore, the changes imply to use two different objects:
- the thread on which an exception occured
- the thread you're currently examining
and that's not a simple task
moreover it'll be hard to understand the difference between the two 
above mentionned thread objects

so, finding another solution might be preferable
what are the thread's missing information you were thinking of ?

A+

-- 
Eric Pouech
"The problem with designing something completely foolproof is to underestimate the ingenuity of a complete idiot." (Douglas Adams)