[Squeak-VMdev] fullDisplay, ioForceDisplay etc

[Tim R. <ti...@su...>]

Whilst playing with all this VM code I noticed a bit of confusion in
the area of fullDisplay and it's cousins.

Strange Mac code - sqMacUIEvents>case: updateEvt -> fullDisplayUpdate
-> ioForceDisplayUpdate -> does nothing. Comment claims to use
ioShowDisplay...

Similar kind of oddity in comments in win32 -
sqWin32window>ioForceDisplayUpdate claims:-
  /* force an update of the squeak window if using deferred updates */
but appears to NOT update if defer is on. Oh and comment in case:
WM_PAINT claims fullDisplayUpdate will call ioShowDisplay too.

In fact there seems to be a little confusion as to which code forces a display
update right now, which can be deferred by the image and which can be
done lazily by the vm. I'd be interested to know what the design intent
is here! Who knows, it might enable me to further improve the RISC OS
performance. 

primitiveBeDisplay comment claims that the Display oop will be recorded
in the specialOopArray as well as a separate variable. Currently there
appears to be no such variable. Shall we change the comment or the
code? A loooong time ago I wanted to have that separate variable but
nobody else liked the idea and I reworked stuff to not need it. Does
anyone want it?

tim
--
Tim Rowledge, ti...@su..., http://sumeru.stanford.edu/tim
Nostalgia:  The good old days multiplied by a bad memory...