mesa: Enable true refcounting for NullBufferObj.

This object can be shared with another context, so we cannot just
delete it when the owning context is being destroyed.

Ensuring that buffer objects are properly refcounted guarantees
NullBufferObj is destroyed when all references to it are removed.

8 files changed, 48 insertions, 10 deletions

diff --git a/src/mesa/main/arrayobj.c b/src/mesa/main/arrayobj.c
index fd35d4e..e36137d 100644
--- a/src/mesa/main/arrayobj.c
+++ b/src/mesa/main/arrayobj.c
@@ -95,6 +95,10 @@ unbind_array_object_vbos(GLcontext *ctx, struct gl_array_object *obj)
 
    for (i = 0; i < Elements(obj->VertexAttrib); i++)
       _mesa_reference_buffer_object(ctx, &obj->VertexAttrib[i].BufferObj,NULL);
+
+#if FEATURE_point_size_array
+   _mesa_reference_buffer_object(ctx, &obj->PointSize.BufferObj, NULL);
+#endif
 }
 
 
diff --git a/src/mesa/main/bufferobj.c b/src/mesa/main/bufferobj.c
index 2271550..dabb138 100644
--- a/src/mesa/main/bufferobj.c
+++ b/src/mesa/main/bufferobj.c
@@ -556,6 +556,17 @@ _mesa_init_buffer_objects( GLcontext *ctx )
 }
 
 
+void
+_mesa_free_buffer_objects( GLcontext *ctx )
+{
+   _mesa_reference_buffer_object(ctx, &ctx->Array.ArrayBufferObj, NULL);
+   _mesa_reference_buffer_object(ctx, &ctx->Array.ElementArrayBufferObj, NULL);
+
+   _mesa_reference_buffer_object(ctx, &ctx->CopyReadBuffer, NULL);
+   _mesa_reference_buffer_object(ctx, &ctx->CopyWriteBuffer, NULL);
+}
+
+
 /**
  * Bind the specified target to buffer for the specified context.
  * Called by glBindBuffer() and other functions.
diff --git a/src/mesa/main/bufferobj.h b/src/mesa/main/bufferobj.h
index 2931962..f8bca5f 100644
--- a/src/mesa/main/bufferobj.h
+++ b/src/mesa/main/bufferobj.h
@@ -60,6 +60,9 @@ extern void
 _mesa_init_buffer_objects( GLcontext *ctx );
 
 extern void
+_mesa_free_buffer_objects( GLcontext *ctx );
+
+extern void
 _mesa_update_default_objects_buffer_objects(GLcontext *ctx);
 
 
diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index fccce51..591aa11 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -955,6 +955,7 @@ _mesa_free_context_data( GLcontext *ctx )
    _mesa_reference_fragprog(ctx, &ctx->FragmentProgram._TexEnvProgram, NULL);
 
    _mesa_free_attrib_data(ctx);
+   _mesa_free_buffer_objects(ctx);
    _mesa_free_lighting_data( ctx );
    _mesa_free_eval_data( ctx );
    _mesa_free_texture_data( ctx );
@@ -974,6 +975,7 @@ _mesa_free_context_data( GLcontext *ctx )
 #if FEATURE_ARB_pixel_buffer_object
    _mesa_reference_buffer_object(ctx, &ctx->Pack.BufferObj, NULL);
    _mesa_reference_buffer_object(ctx, &ctx->Unpack.BufferObj, NULL);
+   _mesa_reference_buffer_object(ctx, &ctx->DefaultPacking.BufferObj, NULL);
 #endif
 
 #if FEATURE_ARB_vertex_buffer_object
diff --git a/src/mesa/main/pixel.c b/src/mesa/main/pixel.c
index f6f9c11..ca6ecd7 100644
--- a/src/mesa/main/pixel.c
+++ b/src/mesa/main/pixel.c
@@ -150,13 +150,17 @@ validate_pbo_access(GLcontext *ctx, struct gl_pixelstore_attrib *pack,
    GLboolean ok;
 
    /* Note, need to use DefaultPacking and Unpack's buffer object */
-   ctx->DefaultPacking.BufferObj = pack->BufferObj;
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->DefaultPacking.BufferObj,
+                                 pack->BufferObj);
 
    ok = _mesa_validate_pbo_access(1, &ctx->DefaultPacking, mapsize, 1, 1,
                                   format, type, ptr);
 
    /* restore */
-   ctx->DefaultPacking.BufferObj = ctx->Shared->NullBufferObj;
+   _mesa_reference_buffer_object(ctx,
+                                 &ctx->DefaultPacking.BufferObj,
+                                 ctx->Shared->NullBufferObj);
 
    if (!ok) {
       _mesa_error(ctx, GL_INVALID_OPERATION,
diff --git a/src/mesa/main/shared.c b/src/mesa/main/shared.c
index a7cf623..b889364 100644
--- a/src/mesa/main/shared.c
+++ b/src/mesa/main/shared.c
@@ -95,12 +95,6 @@ _mesa_alloc_shared_state(GLcontext *ctx)
 
    /* Allocate the default buffer object */
    shared->NullBufferObj = ctx->Driver.NewBufferObject(ctx, 0, 0);
-#ifndef DEBUG
-   /* Set refcount so high that it never gets deleted.
-    * XXX with recent/improved refcounting this should be no longer be needed.
-    */
-   shared->NullBufferObj->RefCount = 1000 * 1000 * 1000;
-#endif
 
    /* Create default texture objects */
    for (i = 0; i < NUM_TEXTURE_TARGETS; i++) {
diff --git a/src/mesa/vbo/vbo_context.c b/src/mesa/vbo/vbo_context.c
index 75c32e0..a5b0070 100644
--- a/src/mesa/vbo/vbo_context.c
+++ b/src/mesa/vbo/vbo_context.c
@@ -249,17 +249,25 @@ void _vbo_InvalidateState( GLcontext *ctx, GLuint new_state )
 
 void _vbo_DestroyContext( GLcontext *ctx )
 {
+   struct vbo_context *vbo = vbo_context(ctx);
+
    if (ctx->aelt_context) {
       _ae_destroy_context( ctx );
       ctx->aelt_context = NULL;
    }
 
-   if (vbo_context(ctx)) {
+   if (vbo) {
+      GLuint i;
+
+      for (i = 0; i < VBO_ATTRIB_MAX; i++) {
+         _mesa_reference_buffer_object(ctx, &vbo->currval[i].BufferObj, NULL);
+      }
+
       vbo_exec_destroy(ctx);
 #if FEATURE_dlist
       vbo_save_destroy(ctx);
 #endif
-      FREE(vbo_context(ctx));
+      FREE(vbo);
       ctx->swtnl_im = NULL;
    }
 }
diff --git a/src/mesa/vbo/vbo_exec_api.c b/src/mesa/vbo/vbo_exec_api.c
index f0a7eea..8ee14be 100644
--- a/src/mesa/vbo/vbo_exec_api.c
+++ b/src/mesa/vbo/vbo_exec_api.c
@@ -759,6 +759,7 @@ void vbo_use_buffer_objects(GLcontext *ctx)
    }
 
    /* Allocate a real buffer object now */
+   _mesa_reference_buffer_object(ctx, &exec->vtx.bufferobj, NULL);
    exec->vtx.bufferobj = ctx->Driver.NewBufferObject(ctx, bufName, target);
    ctx->Driver.BufferData(ctx, target, size, NULL, usage, exec->vtx.bufferobj);
 }
@@ -803,8 +804,19 @@ void vbo_exec_vtx_init( struct vbo_exec_context *exec )
    
    {
       struct gl_client_array *arrays = exec->vtx.arrays;
+      unsigned i;
+
       memcpy(arrays,      vbo->legacy_currval,  16 * sizeof(arrays[0]));
       memcpy(arrays + 16, vbo->generic_currval, 16 * sizeof(arrays[0]));
+
+      for (i = 0; i < 16; ++i) {
+         arrays[i     ].BufferObj = NULL;
+         arrays[i + 16].BufferObj = NULL;
+         _mesa_reference_buffer_object(ctx, &arrays[i     ].BufferObj,
+                                       vbo->legacy_currval[i].BufferObj);
+         _mesa_reference_buffer_object(ctx, &arrays[i + 16].BufferObj,
+                                       vbo->generic_currval[i].BufferObj);
+      }
    }
 
    exec->vtx.vertex_size = 0;