GlExternalAction
GlExternalAction *a = (GlExternalAction *) current_data;
GlExternalAction *a =
(GlExternalAction *) _new_FreeListNode(gl->ext_act_mem);
GlExternalAction *a = (GlExternalAction *) data;
gl->ext_act_mem = _new_FreeList(sizeof(GlExternalAction),
typedef struct GlExternalAction GlExternalAction;