gallium: Unify reference counting.

The core reference counting code is centralized in p_refcnt.h.

This has some consequences related to struct pipe_buffer:

* The screen member of struct pipe_buffer must be initialized, or
  pipe_buffer_reference() will crash trying to destroy a buffer with reference
  count 0. u_simple_screen takes care of this, but I may have missed some of
  the drivers not using it.
* Except for rare exceptions deep in winsys code, buffers must always be
  allocated via pipe_buffer_create() or via screen->*buffer_create() rather
  than via winsys->*buffer_create().

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gallium/state_trackers/dri2/dri_drawable.c b/src/gallium/state_trackers/dri2/dri_drawable.c
index 2f6913ec5c..aa86411190 100644
--- a/src/gallium/state_trackers/dri2/dri_drawable.c
+++ b/src/gallium/state_trackers/dri2/dri_drawable.c
@@ -86,7 +86,7 @@ dri_surface_from_handle(struct pipe_screen *screen,
                                      buf);
 
    /* we don't need the buffer from this point on */
-   pipe_buffer_reference(screen, &buf, NULL);
+   pipe_buffer_reference(&buf, NULL);
 
    if (!texture)
       return NULL;