Re: while_each_thread() under rcu_read_lock() is broken?

[Oleg Nesterov]

On 06/24, Chris Friesen wrote:
>
> On 06/24/2010 12:07 PM, Paul E. McKenney wrote:
>
> > 3.	The thread-group leader might do pthread_exit(), removing itself
> > 	from the thread group -- and might do so while the hapless reader
> > 	is referencing that thread.
> >
> > 	But isn't this prohibited?  Or is it really legal to do a
> > 	pthread_create() to create a new thread and then have the
> > 	parent thread call pthread_exit()?  Not something I would
> > 	consider trying in my own code!  Well, I might, just to
> > 	be perverse, but...  ;-)
>
> I believe SUS allows the main thread to explicitly call pthread_exit(),
> leaving the other threads to run.  If the main() routine just returns
> then it implicitly calls exit().

Correct.

But, to clarify, if the main thread does pthread_exit() (sys_exit,
actually), it won't be removed from the group. It will be zombie
until all other threads exit.

Oleg.

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