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, 36 insertions, 11 deletions

diff --git a/src/gallium/include/pipe/p_state.h b/src/gallium/include/pipe/p_state.h
index a2e839da5c..57a7672d6c 100644
--- a/src/gallium/include/pipe/p_state.h
+++ b/src/gallium/include/pipe/p_state.h
@@ -43,6 +43,8 @@
 #include "p_compiler.h"
 #include "p_defines.h"
 #include "p_format.h"
+#include "p_refcnt.h"
+#include "p_screen.h"
 
 
 #ifdef __cplusplus
@@ -64,23 +66,20 @@ extern "C" {
 
 
 /* fwd decls */
-struct pipe_screen;
 struct pipe_surface;
 
 
-
 /**
  * The driver will certainly subclass this to include actual memory
  * management information.
  */
 struct pipe_buffer
 {
+   struct pipe_reference reference;
+   struct pipe_screen *screen;
    unsigned alignment;
    unsigned usage;
    unsigned size;
-
-   /** Reference count */
-   unsigned refcount;
 };
 
 
@@ -275,6 +274,7 @@ struct pipe_sampler_state
  */
 struct pipe_surface
 {
+   struct pipe_reference reference;
    enum pipe_format format;      /**< PIPE_FORMAT_x */
    unsigned status;              /**< PIPE_SURFACE_STATUS_x */
    unsigned clear_value;         /**< XXX may be temporary */
@@ -282,7 +282,6 @@ struct pipe_surface
    unsigned height;              /**< logical height in pixels */
    unsigned layout;              /**< PIPE_SURFACE_LAYOUT_x */
    unsigned offset;              /**< offset from start of buffer, in bytes */
-   unsigned refcount;
    unsigned usage;               /**< PIPE_BUFFER_USAGE_*  */
 
    struct pipe_texture *texture; /**< texture into which this is a view  */
@@ -306,7 +305,6 @@ struct pipe_transfer
    unsigned nblocksx;            /**< allocated width in blocks */
    unsigned nblocksy;            /**< allocated height in blocks */
    unsigned stride;              /**< stride in bytes between rows of blocks */
-   unsigned refcount;
    unsigned usage;               /**< PIPE_TRANSFER_*  */
 
    struct pipe_texture *texture; /**< texture to transfer to/from  */
@@ -321,6 +319,8 @@ struct pipe_transfer
  */
 struct pipe_texture
 { 
+   struct pipe_reference reference;
+
    enum pipe_texture_target target; /**< PIPE_TEXTURE_x */
    enum pipe_format format;         /**< PIPE_FORMAT_x */
 
@@ -339,10 +339,6 @@ struct pipe_texture
 
    unsigned tex_usage;       /* PIPE_TEXTURE_USAGE_* */
 
-   /* These are also refcounted:
-    */
-   unsigned refcount;
-
    struct pipe_screen *screen; /**< screen that this texture belongs to */
 };
 
@@ -379,6 +375,35 @@ struct pipe_vertex_element
 };
 
 
+/* Reference counting helper functions */
+static INLINE void
+pipe_buffer_reference(struct pipe_buffer **ptr, struct pipe_buffer *buf)
+{
+   struct pipe_buffer *old_buf = *ptr;
+
+   if (pipe_reference((struct pipe_reference **)ptr, &buf->reference))
+      old_buf->screen->buffer_destroy(old_buf);
+}
+
+static INLINE void
+pipe_surface_reference(struct pipe_surface **ptr, struct pipe_surface *surf)
+{
+   struct pipe_surface *old_surf = *ptr;
+
+   if (pipe_reference((struct pipe_reference **)ptr, &surf->reference))
+      old_surf->texture->screen->tex_surface_destroy(old_surf);
+}
+
+static INLINE void
+pipe_texture_reference(struct pipe_texture **ptr, struct pipe_texture *tex)
+{
+   struct pipe_texture *old_tex = *ptr;
+
+   if (pipe_reference((struct pipe_reference **)ptr, &tex->reference))
+      old_tex->screen->texture_destroy(old_tex);
+}
+
+
 #ifdef __cplusplus
 }
 #endif