Re: Greyed Screens during GC

[reti@cambridge.apple.com (Kalman Reti)]

At 10:53 AM 7/19/94 -0400, Ray Pelletier wrote:
>Is there any way to disable or overide the graying which
>occasionally occurs during garbage collection.  I remember this
>being brought up a year or so ago but don't remember the
>responses.
>
>Thanks,
>Ray Pelletier

The best person to answer this (Bill St. Clair) is on vacation, but
as far as I can tell, the answer is maybe.

While GC is happening, you still need to process events, and in
particular update events (e.g. when a window is uncovered).  However,
since you are in the middle of GCing, you don't really have access to
the data with which to repaint the uncovered area, so the GC simply
puts up a constant grey pattern when this occurs.

My understanding is that there is no way to defer these events, that you
have to handle them in some way.  If that's true, the only possible changes
you could make would be to 1) change what constant pattern is used in the
update process or 2) do a dummy update, i.e. call _BeginUpdate/_EndUpdate
without actually updating anything, therefore leaving whatever erroneous bits
were on the screen there for the duration of the GC.

It's easy to patch the system with resedit to do 2).  Open the CODE 0 resource
OF A COPY OF MCL (never, ever patch the original in case you do something
wrong), search for hex a9222f2e0018 (it should only appear once, if it appears
more than once do not go on), change the 2f2e to 6008 and save the copy.
Be sure to give the saved copy a name indicative of the fact that it is a
patched MCL.