From: dvd@davidashen.net
To: 9fans@cse.psu.edu
Subject: Re: [9fans] qunlock
Date: Thu, 24 Jun 2004 02:00:43 +0500 [thread overview]
Message-ID: <b1b442067ff610597d59cd246744559b@davidashen.net> (raw)
In-Reply-To: <7359f0490406231324515faa83@mail.gmail.com>
> you can't do that. what if you do the first unlock,
> then someone else locks it in the interim. you'll
> unlock his lock. bad bad bad.
>
> -rob
It happens in a critical section guarded by another mutex.
Noone else can unlock my lock.
Should I uncomment the commented-out calls below?
void
A()
{
againA:
qlock(a);
qlock(q);
if(x) {
qunlock(q);
goto againA;
}
/* canqlock(b); */
qunlock(b);
qunlock(q);
qunlock(a);
}
void
B()
{
againB:
qlock(b);
qlock(q);
if(y){
qunlock(q);
goto againB;
}
/* canqlock(a); */
qunlock(a);
qunlock(q);
qunlock(b);
}
next prev parent reply other threads:[~2004-06-23 21:00 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-06-22 6:04 dvd
2004-06-22 8:06 ` C H Forsyth
2004-06-22 9:09 ` C H Forsyth
2004-06-22 14:19 ` ron minnich
2004-06-22 14:38 ` boyd, rounin
2004-06-22 15:13 ` Rob Pike
2004-06-23 20:11 ` dvd
2004-06-23 20:24 ` Rob Pike
2004-06-23 21:00 ` dvd [this message]
2004-06-23 21:12 ` boyd, rounin
2004-06-24 7:19 ` Fco. J. Ballesteros
2004-06-24 10:58 ` dvd
2004-06-24 7:34 ` Fco. J. Ballesteros
2004-06-24 11:02 ` dvd
2004-06-24 11:14 ` Fco. J. Ballesteros
2004-06-24 12:18 ` dvd
2004-06-24 13:09 ` Fco. J. Ballesteros
2004-06-24 13:30 ` Sape Mullender
2004-06-24 13:47 ` boyd, rounin
2004-06-24 13:42 ` boyd, rounin
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