WOPEN|ISOPEN, etc.

[chris at umcp-cs.UUCP]

*	From: ptw at vaxine.UUCP

	Is WOPEN set while you sleep for a carrier?

It's supposed to mean ``Waiting for OPEN''.  WOPEN *should*
imply !ISOPEN *for normal usage*, because no one should still be
waiting if someone else has it open.

	Should ISOPEN only be set *after* the carrier comes on?

ISOPEN should be set whenever the line is open.  Typically this
can only be true if the carrier is on (or if it's not on anymore
but some process still has a descriptor to the terminal, which
is actually fairly common... vhangup() was apparently an attempt
to rectify this, but has its own bugs).

	Is there a conventional place to sleep when waiting for
	carrier?  I have seen rawq, outq and tp all used.

Anyplace that's not used by something else... rawq, canq, and
outq aren't likely to be used if no one has the thing open yet.

	Does anybody use BUSY for anything?

Huh?  BUSY?  (I guess not ...)

	How about ASLEEP?

Means the tty is waiting for output to drain, and should be awakend
(on outq I think, too much effort to check from vi here) once the
queue has drained below ttlowat[tp->t_speed].

-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci (301) 454-7690
UUCP:	{seismo,allegra,brl-bmd}!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at maryland