Window Server Internals: Concepts

This section provides introductory and overview material about the internal workings of the Window Server.

Variant: ScreenPlay and non-ScreenPlay. Target audience: Device creators.

• The Window Server Rendering Loop
  This topic provides a brief introduction to the Window Server's rendering loop, which takes place in two stages, known as the upper loop and the lower loop.
• Redraw Stores
  Redraw stores store the sequence of drawing commands representing window contents. Whenever possible, the Window Server performs server-initiated redraws by repeating the sequence of stored commands, rather than by sending redraw requests to the client. This minimises the number of client-server transactions and means that redraws are done as soon as the server detects that they are needed. This topic explains some of the background to redraw stores.