[PATCH] winex11: Don't create a temporary context each time X11DRV_wglBindTexImageARB is called.

[Matteo Bruni]

2016-02-29 3:59 GMT+01:00 Ken Thomases <ken at codeweavers.com>:
> On Feb 26, 2016, at 5:29 PM, Miklós Máté <mtmkls at gmail.com> wrote:
>
>> @@ -2320,6 +2322,7 @@ static BOOL X11DRV_wglDestroyPbufferARB( struct wgl_pbuffer *object )
>>     TRACE("(%p)\n", object);
>>
>>     pglXDestroyPbuffer(gdi_display, object->drawable);
>> +    pglXDestroyContext(gdi_display, object->tmp_context);
>
> I think you need to check if object->tmp_context is non-zero before calling glXDestroyContext() to avoid a GLXBadContext error.
>
>
>> +        if (!object->tmp_context) {
>> +            object->tmp_context = pglXCreateNewContext(gdi_display, object->fmt->fbconfig, object->fmt->render_type, prev_context, True);
>> +            object->prev_context = prev_context;
>> +        } else if (object->prev_context != prev_context) {
>> +            pglXDestroyContext(gdi_display, object->tmp_context);
>> +            object->tmp_context = pglXCreateNewContext(gdi_display, object->fmt->fbconfig, object->fmt->render_type, prev_context, True);
>> +            object->prev_context = prev_context;
>> +        }
>
> Those two branches are mostly the same.  This could be reduced to:
>
>         if (!object->tmp_context || object->prev_context != prev_context) {
>             if (object->tmp_context)
>                 pglXDestroyContext(gdi_display, object->tmp_context);
>             object->tmp_context = pglXCreateNewContext(gdi_display, object->fmt->fbconfig, object->fmt->render_type, prev_context, True);
>             object->prev_context = prev_context;
>         }
>
>
> Is it necessary, when a context is destroyed, to go through all wgl_pbuffer structs looking for any whose prev_context matches the one being destroyed and clear it?  Otherwise, you risk having a stale reference that could be reused for a different context and not realize you need to recreate tmp_context.  Of course, enumerating all of them in a thread-safe manner is going to require a lot of added infrastructure and complexity.

Good point, that's necessary in principle and it shouldn't be too hard
to do by keeping a wgl_pbuffers list (similarly to context_list for
wgl_context, you should probably reuse the same context_section
critical section for synchronization).

The other points brought up by Ken are valid too of course.