How does the death star "working" logo on the UNIXPC work?

[Gil Kloepfer Jr.]

In article <1130 at utoday.UUCP> comeau at .UUCP (Greg Comeau) writes:
>In article <591 at limbic.UUCP> gil at limbic.UUCP (Gil Kloepfer Jr.) writes:
>>The death-star "Working" icon is produced by the window driver, and is
>>on the screen whenever the "current" window (ie. the window attached to the
>>keyboard) is not blocking for input.
>
>I think if I recall correct that the "not blocking for input" is just a subset
>of the possiblities.
>
>If I recall, the logo will only come up having something to do with an
>internal/kernel sleep() call.

I don't have source to the kernel, but I don't think it has anything to do
with kernel sleep() calls.  You can do a lot of something or absolutely
nothing, if the current window is not blocking for input, the working
icon will be on.  If it is blocking for input, the working icon is not on.

If they had to deal with kernel sleeps to handle the icon, there would be
real kludgy things going on inside the kernel in order to implement this.
If you remove the window driver, there is no such thing as a "working"
icon...  I'm 99.9% sure that the code that drives the icon is in the
window driver.

I've seen some real ... let us say "interesting" ... hacks that seem to
be in this kernel, so I won't say you're wrong.  I really doubt that
very much trouble was expended to do that icon, and handling it in the
manner I described is the simplest given the conditions where it seems
to appear.

-------
| Gil Kloepfer, Jr.
| ICUS Software Systems/Bowne Management Systems (depending on where I am)
| ...ames!limbic!gil