[Mesa-dev] [PATCH v2 2/2] glthread/gallium: require safe_glthread to start glthread

[Emil Velikov]

On 3 May 2017 at 17:34, Gregory Hainaut <gregory.hainaut at gmail.com> wrote:
> Otherwise print a warning
>
s/print a warning/$something_bad_that_can_happen/

Print an error message for the user if the requirement is not met, or
we're not thread safe.

> v2: based on Nicolai feedback
> Check the DRI extension version
>
> Signed-off-by: Gregory Hainaut <gregory.hainaut at gmail.com>
> ---
>  src/gallium/state_trackers/dri/dri_context.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/src/gallium/state_trackers/dri/dri_context.c b/src/gallium/state_trackers/dri/dri_context.c
> index 92d79849c4..7c074be63f 100644
> --- a/src/gallium/state_trackers/dri/dri_context.c
> +++ b/src/gallium/state_trackers/dri/dri_context.c
> @@ -153,22 +153,30 @@ dri_create_context(gl_api api, const struct gl_config * visual,
>
>     if (ctx->st->cso_context) {
>        ctx->pp = pp_init(ctx->st->pipe, screen->pp_enabled, ctx->st->cso_context);
>        ctx->hud = hud_create(ctx->st->pipe, ctx->st->cso_context);
>     }
>
>     /* Do this last. */
>     if (ctx->st->start_thread &&
>         /* the driver loader must implement this */
>         screen->sPriv->dri2.backgroundCallable &&
> -       driQueryOptionb(&screen->optionCache, "mesa_glthread"))
> -      ctx->st->start_thread(ctx->st);
> +       /* v2 gives us isGlThreadSafe to ensure thread safety */
> +       screen->sPriv->dri2.backgroundCallable->base.version >= 2 &&
> +       driQueryOptionb(&screen->optionCache, "mesa_glthread")) {
> +
> +      if (ctx->sPriv->dri2.backgroundCallable->isGlThreadSafe(cPriv->loaderPrivate))
Checking screen->sPriv above to use ctx->sPriv here? Something looks a bit off.

> +         ctx->st->start_thread(ctx->st);
> +      else
> +         fprintf(stderr, "MESA warning: glthread can't be enabled because "
> +               "the application didn't call XInitThreads\n");
> +   }
>

   if (ctx->st->start_thread &&
       driQueryOptionb(&screen->optionCache, "mesa_glthread")) {

      if (screen->sPriv->dri2.backgroundCallable &&
          screen->sPriv->dri2.backgroundCallable->base.version >= 2 &&
          screen->sPriv->dri2.backgroundCallable->isGlThreadSafe) {

         if (screen->sPriv->dri2.backgroundCallable->isGlThreadSafe(cPriv->loaderPrivate))
            ctx->st->start_thread(ctx->st);
         else
            fprintf("foo not safe - missing call bar");

      } else {
         fprintf("requested X but driver is missing bar");
      }
   }


Regards,
Emil