2.2.2 Redirection Object Lifetime Management
The desktop composition is based on the existence of nodes in the sprite tree whose content is being rendered by the compositor in a final visual scene. Each logical surface is created at the client upon receipt of a TS_COMPDESK_LSURFACE command. After a logical surface is created, several redirection surfaces MAY be attached to it and detached from it. At any given time, it MUST be true that no more than one redirection surface is attached to a logical surface. When a logical surface is being destroyed, no redirection surface can be attached to it.