Re: [win32] Fix suspend count handling

[Christopher Faylor <cgf-use-the-mailinglist-please@sourceware.org>]

On Sat, Nov 24, 2007 at 06:50:39PM +0100, Lerele wrote:
> Pedro Alves escribi?:
>> Lerele wrote:
>>
>> > This paragraph
>>> makes me ask, maybe the problems you talk about were due to some other 
>>> reason, and not just about using SuspendThread only? Or are you 100% sure 
>>> it's because of that specific function?
>>>
>>
>> Its not the function per se that's the problem.  It's that when we
>> suspend a thread it may be holding some internal lock, or
>> some such.  Calling the same function or another function that accesses
>> the same internal resources from another thread may violate what
>> was expected internally.  My experience on porting gdbserver to WinCE,
>> showed me that on WinCE at least, SuspendThread will not immediatelly
>> suspend the thread -- that probably means that the OS only stops the
>> threads on safe points.  That a look here [1].  It may be that
>> earlier versions of Windows had bugs that made that unsafe.
>> (Windows CE source code is available, but I won't touch it with a
>> ten-meter [2] pole.)
>>
>>
>> [1]
>> http://sourceware.org/ml/gdb-patches/2007-11/msg00220.html
>> -- Yes not perfect, I know.
>>
>> [2]
>> I think metric.
>>
>
> It's actually hard to believe those functions do not work as expected, 
> especially because MSDN docs specifically state using SuspendThread before 
> GetThreadContext, asuming the latter should work after the former, but of 
> course anything is possible.
>
> If that is true, it's useless of course to use them functions.

It's possible that GetThreadContext may wait for pending SuspendThread's.

cgf