ENTER_GL and ActivateContext question

[Alexander Dorofeyev]

Ok, thank you and Roderick for useful info. I figure that my previous patch
wasn't ideal, unfortunately it introduced one more of such recursive ENTERGL /
ActivateContext situations. I'll try to improve that and send another patch.

Regarding moving code around - I wish I was so competent in Direct3D and OpenGL
to freely move code around in wined3d etc :). Hopefully, wine hacking may
improve my grasp on it, but at the moment that's probably over my head. If you
don't object, I'll do basic stuff, like putting additional LEAVE_GL/ENTER_GL in
my own recent change to _BltOverride and wherever else I find similar problem,
and maybe I'll look into possible redundance of glDrawBuffer call Roderick
mentioned.

Also may be worth to think if it's reasonable to put a substantial amount of
effort into eliminating a few redundant gl* calls or a LEAVE_GL/ENTER_GL block
now (then possibly also hunting regressions), when there are major problems like
crashes etc. Say, to use Aliens vs Predator 2 game as an illustration - despite
now one can at least get into the game proper (i.e. load a level), it's still
largerly unusable because of a dinput bug and terrible performance (some
fog-related software emulation fixme - I'll probably submit this to bugzilla).

Stefan Dösinger wrote:
> Am Montag, 10. Dezember 2007 18:39:49 schrieb Alexander Dorofeyev:
>> Hello.
>>
>> I was recently experimenting with a fix that involved ActivateContext and
>> needed to figure out whether it is ok if ActivateContext is called inside
>> ENTER_GL()... LEAVE_GL() (also if recursive ENTER_GL is ok). At first I
>> tried to look for example code in wined3d/surface.c, which seemed to
>> indicate this is ok, because it obviously seems to happen in one or few
>> places. Then I found this
> ActivateContext inside ENTER_GL() and LEAVE_GL() is *not* ok, but it happens 
> in quite a few places unfortunately. The problem this causes is stated in 
> this bugreport. ActivateContext can call GDI calls, and they can deadlock if 
> called between ENTER_GL and LEAVE_GL.
> 
> The example with BindTexture you gave is the main problem indeed, patches like 
> that are a way forward. However, instead of just adding a LEAVE_GL() and 
> ENTER_GL() it should be checked if this can be avoided by moving code around 
> a bit. Be warned that there are a few other troubles with ActivateContext and 
> gl calls as well, for example fbo setup vs ActivateContext