Re: SCO: "thread creation is about a thousand times faster than on native Linux"

From: yodaiken@fsmlabs.com
Date: Thu Aug 24 2000 - 15:09:42 EST


On Thu, Aug 24, 2000 at 10:44:40PM +0200, almesber@lrc.di.epfl.ch wrote:
> yodaiken@fsmlabs.com wrote:
> > The root thread can tell Linux: I'm a pthreads root thread, I don't want
> > POSIX signals, I want raw signals.
>
> Hmm, have you just created unkillable processes any non-privileged
> user can run ?
>
> pthread_trust_me(RAW_SIGNALS_PLEASE);
> for (;;); /* hee hee */

This is not a tough one:

pthread_raw_signals
            This call shifts delivered signal numbers up so that
   "special" POSIX signals can be delivered to a process. Sending signal N to
    a thread that has executed this call causes the kernel to deliver
    signal N+SIG_RAWSHIFT. So kill(pid,SIG_KILL-SIG_RAWSHIFT) is needed
    to hammer such a process.

Or:
    Make it a root pthread daemon.

Or:
    Make SIG_KILL still work as usual, with the CLONE_PTHREAD flag
    causing all children to be killed too, but with SUSPEND etc
    coming in raw.

-- 
---------------------------------------------------------
Victor Yodaiken 
Finite State Machine Labs: The RTLinux Company.
 www.fsmlabs.com  www.rtlinux.com

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