From: James Simmons <jsimmons@edgeglobal.com>
  To  : ggi-develop@eskimo.com
  Date: Sun, 15 Aug 1999 19:50:15 -0400 (EDT)

Re: Ping-pong buffers on KGIcon are here!

> easiest, we'll see.  A better solution, involving no locks at all, would
> be to fault the process to sleep if it touches the framebuffer whilst
> accels are still being processed....

Thats the question. How do you tell if the framebuffer is being accessed?
Especially when mmapped. I would implement such a solution if I knew the
answer to this question.