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Date: Wed, 14 Aug 1996 05:55:43 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199608131955.FAA20954@godzilla.zeta.org.au>
To: freebsd-current@FreeBSD.org, j@uriah.heep.sax.de
Subject: Re: locking up
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>> In polled mode, pcrint() reduces to sgetc().  sgetc() has too many cases
>> for me to understand.  It seems to return too early in some cases, but not
>> when Debugger() is called.

>It only returns early if `noblock' is specified.  (It returns NULL in
>that case.)  Otherwise, it loops again instead.

`noblock' is always set in the calls from pcrint(), so this guarantees
that there is a problem if sgetc() is actually called from pcrint().
I think the first call (for the !PCVT_KBD_FIFO case) never occurs
(pcrint() is always blocked when kbd_polling != 0).

scgetc() also seems to return early in all cases when XSERVER != 0.

I think there is a problem iff PCVT_KBD_FIFO != 0.

Bruce