Re: AW: Specific Linux syscalls for glibc API

[Szabolcs Nagy <szabolcs dot nagy at arm dot com>]

On 18/11/15 16:07, Szabolcs Nagy wrote:
> On 18/11/15 12:57, Warlich, Christof wrote:
> > On 11/17/2015 05:34 PM, Joseph Myers wrote
> > > * gettid, pthread_gettid_np (bug 6399).
> >
> > I'm not sure w.r.t. the added value of a gettid wrapper though: Assuming the
> > availability of pthread_gettid_np(), pthread_gettid_np(pthread_self()) would
> > (apart from some locking to prevent thread termination in the meantime) just
> > do what gettid() is supposed to do.
>
> i don't see why would you lock there.
> (this api should be as-safe)
>
> pthread_gettid_np is problematic api because of the
> issue Florian raised (tid is lost after a thread
> exited but not yet joined and that should not be
> visible to the caller, so this api is only possible
> to implement if tid handling is redesigned).

ignore this

tid is not useful after the thread exited,
so using a tid has to be synched with thread
exit, so the user of the tid must know about
the thread exit event, pthread_gettid_np does
not expose anything it shouldn't.