Add initial prototype.

3-mid/opengl/source/opengl-tasks.adb

@@ -0,0 +1,32 @@
+package body openGL.Tasks
+is
+
+   procedure check
+   is
+      use Ada,
+          ada.Task_Identification;
+
+      calling_Task : constant Task_Id := Task_Identification.current_Task;
+
+      --  TODO: Use the assert instead of the exception for performance.
+      --  pragma assert (Renderer_Task = calling_Task,
+      --                   "Calling task '"      & Task_Identification.Image (current_Task)  & "'"
+      --                 & " /= Renderer task '" & Task_Identification.Image (Renderer_Task) & "'");
+   begin
+      if Renderer_Task /= calling_Task
+      then
+         raise Error with   "Calling task '"      & Task_Identification.Image (current_Task)  & "'"
+                          & " /= Renderer task '" & Task_Identification.Image (Renderer_Task) & "'";
+      end if;
+   end check;
+
+
+
+   function check return Boolean
+   is
+   begin
+      check;
+      return True;
+   end check;
+
+end openGL.Tasks;