gallium: implement the backend of threaded GL dispatch

Acked-by: Timothy Arceri <[email protected]>
Tested-by: Dieter Nützel <[email protected]>
Tested-by: Mike Lothian <[email protected]>

4 files changed, 56 insertions, 0 deletions

diff --git a/src/gallium/include/state_tracker/st_api.h b/src/gallium/include/state_tracker/st_api.h
index a9997744cde..bf9a7e95d7c 100644
--- a/src/gallium/include/state_tracker/st_api.h
+++ b/src/gallium/include/state_tracker/st_api.h
@@ -417,6 +417,19 @@ struct st_context_iface
     */
    boolean (*get_resource_for_egl_image)(struct st_context_iface *stctxi,
                                          struct st_context_resource *stres);
+
+   /**
+    * Start the thread if the API has a worker thread.
+    * Called after the context has been created and fully initialized on both
+    * sides (e.g. st/mesa and st/dri).
+    */
+   void (*start_thread)(struct st_context_iface *stctxi);
+
+   /**
+    * If the API is multithreaded, wait for all queued commands to complete.
+    * Called from the main thread.
+    */
+   void (*thread_finish)(struct st_context_iface *stctxi);
 };
 
 
@@ -454,6 +467,12 @@ struct st_manager
     */
    int (*get_param)(struct st_manager *smapi,
                     enum st_manager_param param);
+
+   /**
+    * Call the loader function setBackgroundContext. Called from the worker
+    * thread.
+    */
+   void (*set_background_context)(struct st_context_iface *stctxi);
 };
 
 /**
diff --git a/src/gallium/state_trackers/dri/dri_context.c b/src/gallium/state_trackers/dri/dri_context.c
index 3d8af65ca61..91d2d1fbbe8 100644
--- a/src/gallium/state_trackers/dri/dri_context.c
+++ b/src/gallium/state_trackers/dri/dri_context.c
@@ -156,6 +156,13 @@ dri_create_context(gl_api api, const struct gl_config * visual,
       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);
+
    *error = __DRI_CTX_ERROR_SUCCESS;
    return GL_TRUE;
 
@@ -222,6 +229,9 @@ dri_make_current(__DRIcontext * cPriv,
    struct dri_drawable *read = dri_drawable(driReadPriv);
    struct st_context_iface *old_st = ctx->stapi->get_current(ctx->stapi);
 
+   if (old_st && old_st->thread_finish)
+      old_st->thread_finish(old_st);
+
    /* Flush the old context here so we don't have to flush on unbind() */
    if (old_st && old_st != ctx->st)
       old_st->flush(old_st, ST_FLUSH_FRONT, NULL);
diff --git a/src/gallium/state_trackers/dri/dri_drawable.c b/src/gallium/state_trackers/dri/dri_drawable.c
index fd3b458de6c..3c2e3075249 100644
--- a/src/gallium/state_trackers/dri/dri_drawable.c
+++ b/src/gallium/state_trackers/dri/dri_drawable.c
@@ -217,9 +217,13 @@ dri_set_tex_buffer2(__DRIcontext *pDRICtx, GLint target,
                     GLint format, __DRIdrawable *dPriv)
 {
    struct dri_context *ctx = dri_context(pDRICtx);
+   struct st_context_iface *st = ctx->st;
    struct dri_drawable *drawable = dri_drawable(dPriv);
    struct pipe_resource *pt;
 
+   if (st->thread_finish)
+      st->thread_finish(st);
+
    dri_drawable_validate_att(ctx, drawable, ST_ATTACHMENT_FRONT_LEFT);
 
    /* Use the pipe resource associated with the X drawable */
@@ -453,6 +457,8 @@ dri_flush(__DRIcontext *cPriv,
    }
 
    st = ctx->st;
+   if (st->thread_finish)
+      st->thread_finish(st);
 
    if (drawable) {
       /* prevent recursion */
diff --git a/src/gallium/state_trackers/dri/dri_screen.c b/src/gallium/state_trackers/dri/dri_screen.c
index 9b37dff6778..799a2649b04 100644
--- a/src/gallium/state_trackers/dri/dri_screen.c
+++ b/src/gallium/state_trackers/dri/dri_screen.c
@@ -33,6 +33,7 @@
 #include "xmlpool.h"
 
 #include "dri_screen.h"
+#include "dri_context.h"
 
 #include "util/u_inlines.h"
 #include "pipe/p_screen.h"
@@ -53,6 +54,10 @@ const __DRIconfigOptionsExtension gallium_config_options = {
    .xml =
 
    DRI_CONF_BEGIN
+      DRI_CONF_SECTION_PERFORMANCE
+         DRI_CONF_MESA_GLTHREAD("false")
+      DRI_CONF_SECTION_END
+
       DRI_CONF_SECTION_QUALITY
          DRI_CONF_FORCE_S3TC_ENABLE("false")
          DRI_CONF_PP_CELSHADE(0)
@@ -432,6 +437,21 @@ dri_postprocessing_init(struct dri_screen *screen)
    }
 }
 
+static void
+dri_set_background_context(struct st_context_iface *st)
+{
+   struct dri_context *ctx = (struct dri_context *)st->st_manager_private;
+   const __DRIbackgroundCallableExtension *backgroundCallable =
+      ctx->sPriv->dri2.backgroundCallable;
+
+   /* Note: Mesa will only call this function if GL multithreading is enabled
+    * We only do that if the loader exposed the __DRI_BACKGROUND_CALLABLE
+    * extension. So we know that backgroundCallable is not NULL.
+    */
+   assert(backgroundCallable);
+   backgroundCallable->setBackgroundContext(ctx->cPriv->loaderPrivate);
+}
+
 const __DRIconfig **
 dri_init_screen_helper(struct dri_screen *screen,
                        struct pipe_screen *pscreen,
@@ -440,6 +460,7 @@ dri_init_screen_helper(struct dri_screen *screen,
    screen->base.screen = pscreen;
    screen->base.get_egl_image = dri_get_egl_image;
    screen->base.get_param = dri_get_param;
+   screen->base.set_background_context = dri_set_background_context;
 
    screen->st_api = st_gl_api_create();
    if (!screen->st_api)