mesa: Always do proper ref counting of shared state.

src/mesa/main/context.c

@@ -835,7 +835,7 @@ _mesa_initialize_context(GLcontext *ctx,
    _glthread_UNLOCK_MUTEX(shared->Mutex);
 
    if (!init_attrib_groups( ctx )) {
-      _mesa_free_shared_state(ctx, ctx->Shared);
+      _mesa_release_shared_state(ctx, ctx->Shared);
       return GL_FALSE;
    }
 
@@ -843,7 +843,7 @@ _mesa_initialize_context(GLcontext *ctx,
    ctx->Exec = alloc_dispatch_table();
    ctx->Save = alloc_dispatch_table();
    if (!ctx->Exec || !ctx->Save) {
-      _mesa_free_shared_state(ctx, ctx->Shared);
+      _mesa_release_shared_state(ctx, ctx->Shared);
       if (ctx->Exec)
          _mesa_free(ctx->Exec);
       return GL_FALSE;
@@ -933,8 +933,6 @@ _mesa_create_context(const GLvisual *visual,
 void
 _mesa_free_context_data( GLcontext *ctx )
 {
-   GLint RefCount;
-
    if (!_mesa_get_current_context()){
       /* No current context, but we may need one in order to delete
        * texture objs, etc.  So temporarily bind the context now.
@@ -988,14 +986,7 @@ _mesa_free_context_data( GLcontext *ctx )
    _mesa_free(ctx->Save);
 
    /* Shared context state (display lists, textures, etc) */
-   _glthread_LOCK_MUTEX(ctx->Shared->Mutex);
+   _mesa_release_shared_state( ctx, ctx->Shared );
-   RefCount = --ctx->Shared->RefCount;
-   _glthread_UNLOCK_MUTEX(ctx->Shared->Mutex);
-   assert(RefCount >= 0);
-   if (RefCount == 0) {
-      /* free shared state */
-      _mesa_free_shared_state( ctx, ctx->Shared );
-   }
 
    /* needs to be after freeing shared state */
    _mesa_free_display_list_data(ctx);
@@ -1397,7 +1388,6 @@ _mesa_share_state(GLcontext *ctx, GLcontext *ctxToShare)
 {
    if (ctx && ctxToShare && ctx->Shared && ctxToShare->Shared) {
       struct gl_shared_state *oldSharedState = ctx->Shared;
-      GLint RefCount;
 
       ctx->Shared = ctxToShare->Shared;
       
@@ -1407,13 +1397,7 @@ _mesa_share_state(GLcontext *ctx, GLcontext *ctxToShare)
 
       update_default_objects(ctx);
 
-      _glthread_LOCK_MUTEX(oldSharedState->Mutex);
+      _mesa_release_shared_state(ctx, oldSharedState);
-      RefCount = --oldSharedState->RefCount;
-      _glthread_UNLOCK_MUTEX(oldSharedState->Mutex);
-
-      if (RefCount == 0) {
-         _mesa_free_shared_state(ctx, oldSharedState);
-      }
 
       return GL_TRUE;
    }

src/mesa/main/shared.c

@@ -288,8 +288,8 @@ delete_renderbuffer_cb(GLuint id, void *data, void *userData)
  *
  * \sa alloc_shared_state().
  */
-void
+static void
-_mesa_free_shared_state(GLcontext *ctx, struct gl_shared_state *shared)
+free_shared_state(GLcontext *ctx, struct gl_shared_state *shared)
 {
    GLuint i;
 
@@ -368,3 +368,30 @@ _mesa_free_shared_state(GLcontext *ctx, struct gl_shared_state *shared)
 
    _mesa_free(shared);
 }
+
+
+/**
+ * Decrement shared state object reference count and potentially free it
+ * and all children structures.
+ *
+ * \param ctx GL context.
+ * \param shared shared state pointer.
+ *
+ * \sa free_shared_state().
+ */
+void
+_mesa_release_shared_state(GLcontext *ctx, struct gl_shared_state *shared)
+{
+   GLint RefCount;
+
+   _glthread_LOCK_MUTEX(shared->Mutex);
+   RefCount = --shared->RefCount;
+   _glthread_UNLOCK_MUTEX(shared->Mutex);
+
+   assert(RefCount >= 0);
+
+   if (RefCount == 0) {
+      /* free shared state */
+      free_shared_state( ctx, shared );
+   }
+}

src/mesa/main/shared.h

@@ -31,7 +31,7 @@ _mesa_alloc_shared_state(GLcontext *ctx);
 
 
 void
-_mesa_free_shared_state(GLcontext *ctx, struct gl_shared_state *shared);
+_mesa_release_shared_state(GLcontext *ctx, struct gl_shared_state *shared);
 
 
 #endif