From owner-cvs-sys  Sun Jul 30 05:39:50 1995
Return-Path: cvs-sys-owner
Received: (from majordom@localhost)
          by freefall.cdrom.com (8.6.11/8.6.6) id FAA05973
          for cvs-sys-outgoing; Sun, 30 Jul 1995 05:39:50 -0700
Received: (from bde@localhost)
          by freefall.cdrom.com (8.6.11/8.6.6) id FAA05963
          ; Sun, 30 Jul 1995 05:39:44 -0700
Date: Sun, 30 Jul 1995 05:39:44 -0700
From: Bruce Evans <bde>
Message-Id: <199507301239.FAA05963@freefall.cdrom.com>
To: CVS-commiters, cvs-sys
Subject: cvs commit: src/sys/sys tty.h
Sender: cvs-sys-owner@freebsd.org
Precedence: bulk

bde         95/07/30 05:39:43

  Modified:    sys/kern  tty.c
               sys/sys   tty.h
  Log:
  Split TS_ASLEEP (sleep on output [below low water])into TS_SO_OLOWAT (sleep
  on output below low water) and TS_SO_OCOMPLETE (sleep on output complete).
  Most of the support for this has already been committed.  Drivers should
  call ttwwakeup() to handle wakeups whenever output is below low water
  (and some output event causes this condition to be checked) or TS_BUSY is
  cleared.
  
  tty.c:
  Fix the livelock in ttywait() properly by sleeping on output complete, not
  on output below low water.
  
  Use ttwwakeup() instead of separate select and output wakeups for all
  wakeups of writers.
  
  Add wakeups of writers for output flushes and carrier/clocal transitions.
  
  Don't go to sleep in ttycheckoutq() if ttstart() reduces the queue to below
  low water.
  
  Use the timeout built into tsleep() in ttycheckoutq().
  
  Optimize the select wakeup in ttwwakeup().  It seems reasonable to know
  too much about the internals of tp->t_wsel now that the knowledge is
  localised in tty.c.