[Mesa-dev] [PATCH 21/23] meta/TexSubImage: Don't pollute the buffer object namespace

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

tl;dr: For many types of GL object, we can *NEVER* use the Gen function.

In OpenGL ES (all versions!) and OpenGL compatibility profile,
applications don't have to call Gen functions.  The GL spec is very
clear about how you can mix-and-match generated names and non-generated
names: you can use any name you want for a particular object type until
you call the Gen function for that object type.

Here's the problem scenario:

 - Application calls a meta function that generates a name.  The first
   Gen will probably return 1.

 - Application decides to use the same name for an object of the same
   type without calling Gen.  Many demo programs use names 1, 2, 3,
   etc. without calling Gen.

 - Application calls the meta function again, and the meta function
   replaces the data.  The application's data is lost, and the app
   fails.  Have fun debugging that.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92363
---
 src/mesa/drivers/common/meta_tex_subimage.c | 42 ++++++++++++++++-------------
 1 file changed, 24 insertions(+), 18 deletions(-)

diff --git a/src/mesa/drivers/common/meta_tex_subimage.c b/src/mesa/drivers/common/meta_tex_subimage.c
index b0ac677..4adaad7 100644
--- a/src/mesa/drivers/common/meta_tex_subimage.c
+++ b/src/mesa/drivers/common/meta_tex_subimage.c
@@ -69,7 +69,7 @@ create_texture_for_pbo(struct gl_context *ctx,
                        int dims, int width, int height, int depth,
                        GLenum format, GLenum type, const void *pixels,
                        const struct gl_pixelstore_attrib *packing,
-                       GLuint *tmp_pbo, GLuint *tmp_tex)
+                       struct gl_buffer_object **tmp_pbo, GLuint *tmp_tex)
 {
    uint32_t pbo_format;
    GLenum internal_format;
@@ -101,7 +101,7 @@ create_texture_for_pbo(struct gl_context *ctx,
    row_stride = _mesa_image_row_stride(packing, width, format, type);
 
    if (_mesa_is_bufferobj(packing->BufferObj)) {
-      *tmp_pbo = 0;
+      *tmp_pbo = NULL;
       buffer_obj = packing->BufferObj;
       first_pixel += (intptr_t)pixels;
    } else {
@@ -109,23 +109,27 @@ create_texture_for_pbo(struct gl_context *ctx,
 
       assert(create_pbo);
 
-      _mesa_CreateBuffers(1, tmp_pbo);
+      *tmp_pbo = ctx->Driver.NewBufferObject(ctx, 0xDEADBEEF);
+      if (*tmp_pbo == NULL)
+         return NULL;
 
       /* In case of GL_PIXEL_PACK_BUFFER, pass null pointer for the pixel
-       * data to avoid unnecessary data copying in _mesa_NamedBufferData().
+       * data to avoid unnecessary data copying in _mesa_buffer_data.
        */
       if (is_pixel_pack)
-         _mesa_NamedBufferData(*tmp_pbo,
-                               last_pixel - first_pixel,
-                               NULL,
-                               GL_STREAM_READ);
+         _mesa_buffer_data(ctx, *tmp_pbo, GL_NONE,
+                           last_pixel - first_pixel,
+                           NULL,
+                           GL_STREAM_READ,
+                           __func__);
       else
-         _mesa_NamedBufferData(*tmp_pbo,
-                               last_pixel - first_pixel,
-                               (char *)pixels + first_pixel,
-                               GL_STREAM_DRAW);
+         _mesa_buffer_data(ctx, *tmp_pbo, GL_NONE,
+                           last_pixel - first_pixel,
+                           (char *)pixels + first_pixel,
+                           GL_STREAM_DRAW,
+                           __func__);
 
-      buffer_obj = _mesa_lookup_bufferobj(ctx, *tmp_pbo);
+      buffer_obj = *tmp_pbo;
       first_pixel = 0;
    }
 
@@ -157,7 +161,7 @@ create_texture_for_pbo(struct gl_context *ctx,
                                                      row_stride,
                                                      read_only)) {
       _mesa_DeleteTextures(1, tmp_tex);
-      _mesa_DeleteBuffers(1, tmp_pbo);
+      _mesa_reference_buffer_object(ctx, tmp_pbo, NULL);
       return NULL;
    }
 
@@ -173,7 +177,8 @@ _mesa_meta_pbo_TexSubImage(struct gl_context *ctx, GLuint dims,
                            bool allocate_storage, bool create_pbo,
                            const struct gl_pixelstore_attrib *packing)
 {
-   GLuint pbo = 0, pbo_tex = 0, fbos[2] = { 0, 0 };
+   struct gl_buffer_object *pbo = NULL;
+   GLuint pbo_tex = 0, fbos[2] = { 0, 0 };
    int image_height;
    struct gl_texture_image *pbo_tex_image;
    GLenum status;
@@ -276,7 +281,7 @@ _mesa_meta_pbo_TexSubImage(struct gl_context *ctx, GLuint dims,
 fail:
    _mesa_DeleteFramebuffers(2, fbos);
    _mesa_DeleteTextures(1, &pbo_tex);
-   _mesa_DeleteBuffers(1, &pbo);
+   _mesa_reference_buffer_object(ctx, &pbo, NULL);
 
    _mesa_meta_end(ctx);
 
@@ -291,7 +296,8 @@ _mesa_meta_pbo_GetTexSubImage(struct gl_context *ctx, GLuint dims,
                               GLenum format, GLenum type, const void *pixels,
                               const struct gl_pixelstore_attrib *packing)
 {
-   GLuint pbo = 0, pbo_tex = 0, fbos[2] = { 0, 0 };
+   struct gl_buffer_object *pbo = NULL;
+   GLuint pbo_tex = 0, fbos[2] = { 0, 0 };
    int image_height;
    struct gl_texture_image *pbo_tex_image;
    struct gl_renderbuffer *rb = NULL;
@@ -448,7 +454,7 @@ _mesa_meta_pbo_GetTexSubImage(struct gl_context *ctx, GLuint dims,
 fail:
    _mesa_DeleteFramebuffers(2, fbos);
    _mesa_DeleteTextures(1, &pbo_tex);
-   _mesa_DeleteBuffers(1, &pbo);
+   _mesa_reference_buffer_object(ctx, &pbo, NULL);
 
    _mesa_meta_end(ctx);
 
-- 
2.1.0