PERFORCE change 146845 for review

[Ed Schouten]

http://perforce.freebsd.org/chv.cgi?CH=146845

Change 146845 by ed at ed_dull on 2008/08/07 17:53:38

	Remove the now unused t_threadcnt variable from struct tty. Now
	we use the safer destroy_dev_sched_cb(), there is no harm to
	destroy TTY's when threads are still inside the TTY layer
	through the character devices.

Affected files ...

.. //depot/projects/mpsafetty/sys/kern/tty.c#16 edit
.. //depot/projects/mpsafetty/sys/sys/tty.h#5 edit

Differences ...

==== //depot/projects/mpsafetty/sys/kern/tty.c#16 (text+ko) ====

@@ -166,10 +166,9 @@
 		/* Device is already gone */
 		tty_unlock(tp);
 		return (ENXIO);
-	} else {
-		tp->t_threadcnt++;
-		return (0);
 	}
+
+	return (0);
 }
 
 static void
@@ -177,10 +176,7 @@
 {
 	tty_lock_assert(tp, MA_OWNED);
 
-	MPASS(tp->t_threadcnt > 0);
-	tp->t_threadcnt--;
-	if (tty_opened(tp) || tp->t_threadcnt > 0 ||
-	    tp->t_flags & TF_OPENCLOSE) {
+	if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
 		/* Device is still opened somewhere */
 		tty_unlock(tp);
 		return;
@@ -245,7 +241,6 @@
 		tty_unlock(tp);
 		return (EBUSY);
 	}
-	tp->t_threadcnt++;
 	tp->t_flags |= TF_OPENCLOSE;
 
 	/*
@@ -315,7 +310,6 @@
 	struct tty *tp = dev->si_drv1;
 
 	tty_lock(tp);
-	tp->t_threadcnt++;
 
 	/*
 	 * This can only be called once. The callin and the callout
@@ -930,7 +924,7 @@
 
 	tty_lock_assert(tp, MA_OWNED);
 
-	if (tp->t_sessioncnt != 0 || tp->t_threadcnt != 0 ||
+	if (tp->t_sessioncnt != 0 ||
 	    (tp->t_flags & (TF_GONE|TF_OPENED)) != TF_GONE) {
 		/* TTY is still in use */
 		tty_unlock(tp);

==== //depot/projects/mpsafetty/sys/sys/tty.h#5 (text+ko) ====

@@ -79,8 +79,6 @@
 #define	TF_EXCLUDE	0x1000	/* Exclusive access */
 #define	TF_BYPASS	0x2000	/* Optimized input path */
 #define	TF_ZOMBIE	0x4000	/* Modem disconnect received */
-
-	unsigned int	t_threadcnt;	/* (t) Threads in cdev */
 	unsigned int	t_revokecnt;	/* (t) revoke() count */
 
 	/* Buffering mechanisms */