Re: deferred cancellation of ipc

[Marcus Brinkmann]

On Thu, Oct 16, 2003 at 09:23:42AM +1000, Stefan G?tz wrote:
> On Wed, 2003-10-15 at 09:49, Marcus Brinkmann wrote:
> > > > Or does maybe stopping a thread on another CPU count as 
> > > > preemption and is also delayed?
> > > 
> > > Sorry, but I don't get what you mean.  What is "stopping"; exregs?
> > 
> > Yes.  Also called halting.  If I stop/halt a thread on another cpu, will
> > this stop/halt the thread even if it delayed preemption?  Or does preemption
> > delay prevent that?
> 
> Yes. No. DPs do not alter the effects of system calls like ThreadControl
> or ExchangeRegisters.

This means that I can not implement MP safe atomic operations using DPs, and
DP is not a solution to the problem as stated.

Thanks,
Marcus

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Marcus Brinkmann              The Hurd http://www.gnu.org/software/hurd/
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