Re: [Arianne-general] BUG found ( almost sure )

[Miguel A. B. L. <sa...@re...>]

> > I read this is SDL ML. One man had spent all a day trying to do a Increment
> > function with Mutex and it didn't run.
>
> Understanding problem: Increment function == recursive function ? Or a function
> that (atomically) increments some variable ?
> Is there a good signal/noise-ratio on the SDL ML ?

Yes, from time to time there is a noise post, but most  of the time are problems you
find while developing in SDL.

> > SDL-1.1.5 come with Semaphores that are the correct instrument to use.
>
> I don´t see much use for a mutex at all, semaphores are much mor useful,
> althoug possibly slower. Do we have so many concurrent accesses that the faster
> mutices make a difference ? Else we could also provide a Semaphore-class, which
> won´t bug us with those problems.
> btw: If no native semaphore-class is available, SDL does it with a mutex, an
> owner-ID, a lock-count etc...

I will try to do it Threadless at all in a begin, to see if the problem "really" comes
from there. But we should use Semaphore.

> > The problem is that Mutex only locks ( and make the caller to wait ) if it is the
> > same thread that create the Mutex.
>
> You mean, if thread A created the mutex and thread B tries to lock it, something
> terrible happens?

And B tries to lock and A has locked it before, the B simply continue, it should stop
there, but it continues.
Do you see the problem?.

If we are managing pointers on the list in thread A and B enter to the list too, it
break the whole list.

>  If so, on which system? I wrote my threadtest-example also to test mutices: If
> you remove all the TempLocks on the static m_mutex, the output of the different
> threads often appears atop of each other.
>
> > It is a pain to debug a multithread app.
> Sometimes I understand why MSVC++6 Enterprise Edition costs 3500DM ...

"Didn't it come in a CD with Windows 98 and cost 10$ ?", Just joking.
Anyway whatever you use to debug Thread it is imposible to do, the better you can do is
a formal demostration of  the correctness of the program, that is also a pain.
--
                  Miguel Angel Blanch Lardin

             -- http://www.arianne.cx -- Arianne --
The free open source massively multiplayer online role playing game

nuclear cia fbi spy password code encrypt president bomb iran irak korea cuba
Echelon must die