wtm@neoucom.UUCP (Bill Mayhew) (06/30/89)
Hi, Does anybody know what situations cause [apparently] the kernel to display the working icon on the console terminal. Casual observation seems to indicate that that the icon is displayed whenever the foreground task of the console process group has not been in keyboard wait for mote than about 500 mS. I noticed that when I run a P/D basic interpreter that I compiled on the 3b1 assuming only generic Sys V, that the working icon is off while basic is in immediate mode. The icon pops up about 1/2 second after RUN has been invoked. Basic is nothing more than a big C program -- no assembly language subroutines, etc. Looks like scanf keeps the icon turned off, while beginning RUN allows the icon to pop back up. I don't have anything special in mind for the working icon; I'd just like to know more about what it is really telling me about what is going on. I am a bit curious about the CPU overhead eaten by the icon; it would seem that the kernel must have to keep looking at the process table to see if the task is blocked waiting for input .. or is it implemented as part of the console tty driver?... Bill try wtm@neoucom.UUCP also wtm@impulse.UUCP
jbm@uncle.UUCP (John B. Milton) (06/30/89)
In article <1668@neoucom.UUCP> wtm@neoucom.UUCP (Bill Mayhew) writes:
[ how does the working icon work? ]
The working icon is generated by the window system, that is it will not come
up until the wind loadable device driver is loaded. You are correct about when
it comes up, only when the active window has been blocked on input for some
time. There are utilities on THE STORE! for modifying the bit map for the icon,
if you want to see something else besides the death star. As for CPU
consumption, don't worry, it is all aligned long word moves, ignoring what was
on the screen before.
John
--
John Bly Milton IV, jbm@uncle.UUCP, n8emr!uncle!jbm@osu-cis.cis.ohio-state.edu
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