Re: [NEW PATCH] POSIX timers for 2.3.26

Alan Cox (alan@lxorguk.ukuu.org.uk)
Wed, 10 Nov 1999 18:07:28 +0000 (GMT)

> > > + timers = current->posix_timers = itimer_struct_new();
> >
> > What if two threads sharing timers execute this at the same time. I suspect
> > you need to guard this with the tasklist lock perhaps ?
>
> If you have two threads sharing timers the current->posix_timers is
> already initialized in fork.c when the clone_flags has the CLONE_ITIMERS
> bit set.

Good point.

> > Also consider exec and a setuid program getting started with suprise signals
> > pending. I suspect execve needs to kill these timers ?
>
> The timers are not inherited/copied across a fork, so do pending
> signals.

exec not fork. Consider executing a setuid program. I think an exec should
clear the timers ?

> Signal queues cannot be shared between threads. I recall that this is one
> of the remaining incompatibilities of LinuxThreads with POSIX threads.

If you have ideas how to sort the queue sharing btw lots of people want this.

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