Date: Fri, 20 Jul 2001 08:57:23 -0700 From: Julian Elischer <julian@elischer.org> To: current@freebsd.org Subject: huh? in Selrecord(): what is this for? Message-ID: <3B5854E3.B6D9C86D@elischer.org>
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void
selrecord(selector, sip)
struct proc *selector;
struct selinfo *sip;
{
struct proc *p;
pid_t mypid;
mypid = selector->p_pid;
if (sip->si_pid == mypid)
return;
if (sip->si_pid && (p = pfind(sip->si_pid))) {
Why do we look up 'p' when we got it as an argument?
(race condition detection?)
(I'm modifying things for threads so I came up against this....)
mtx_lock_spin(&sched_lock);
if (p->p_wchan == (caddr_t)&selwait) {
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
sip->si_flags |= SI_COLL;
return;
}
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
}
sip->si_pid = mypid;
}
--
+------------------------------------+ ______ _ __
| __--_|\ Julian Elischer | \ U \/ / hard at work in
| / \ julian@elischer.org +------>x USA \ a very strange
| ( OZ ) \___ ___ | country !
+- X_.---._/ presently in San Francisco \_/ \\
v
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