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, 2 insertions, 2 deletions

diff --git a/src/gallium/state_trackers/python/st_softpipe_winsys.c b/src/gallium/state_trackers/python/st_softpipe_winsys.c
index 4d798df99b..426f347d18 100644
--- a/src/gallium/state_trackers/python/st_softpipe_winsys.c
+++ b/src/gallium/state_trackers/python/st_softpipe_winsys.c
@@ -124,7 +124,7 @@ st_softpipe_buffer_create(struct pipe_winsys *winsys,
 {
    struct st_softpipe_buffer *buffer = CALLOC_STRUCT(st_softpipe_buffer);
 
-   buffer->base.refcount = 1;
+   pipe_reference_init(&buffer->base.reference, 1);
    buffer->base.alignment = alignment;
    buffer->base.usage = usage;
    buffer->base.size = size;
@@ -149,7 +149,7 @@ st_softpipe_user_buffer_create(struct pipe_winsys *winsys,
    if(!buffer)
       return NULL;
    
-   buffer->base.refcount = 1;
+   pipe_reference_init(&buffer->base.reference, 1);
    buffer->base.size = bytes;
    buffer->userBuffer = TRUE;
    buffer->data = ptr;