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, 3 insertions, 3 deletions

diff --git a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_slab.c b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_slab.c
index a3259351b9..2cdb5a5e29 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_slab.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_slab.c
@@ -202,7 +202,7 @@ pb_slab_buffer_destroy(struct pb_buffer *_buf)
 
    pipe_mutex_lock(mgr->mutex);
    
-   assert(buf->base.base.refcount == 0);
+   assert(buf->base.base.reference.count == 0);
    
    buf->mapCount = 0;
 
@@ -340,7 +340,7 @@ pb_slab_create(struct pb_slab_manager *mgr)
 
    buf = slab->buffers;
    for (i=0; i < numBuffers; ++i) {
-      buf->base.base.refcount = 0;
+      pipe_reference_init(&buf->base.base.reference, 0);
       buf->base.base.size = mgr->bufSize;
       buf->base.base.alignment = 0;
       buf->base.base.usage = 0;
@@ -419,7 +419,7 @@ pb_slab_manager_create_buffer(struct pb_manager *_mgr,
    pipe_mutex_unlock(mgr->mutex);
    buf = LIST_ENTRY(struct pb_slab_buffer, list, head);
    
-   ++buf->base.base.refcount;
+   pipe_reference_init(&buf->base.base.reference, 1);
    buf->base.base.alignment = desc->alignment;
    buf->base.base.usage = desc->usage;