Re: CVS commit: src/lib/libpthread

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Fri, Jun 26, 2015 at 12:07:36PM +0000, Antti Kantee wrote:
> On 26/06/15 11:53, Joerg Sonnenberger wrote:
> >That said, have
> >you verified why it doesn't happen with libstdc++ itself? I would
> >somewhat suspect that the threatment of the header as system header
> >hides the problem for libstdc++, I can't imagine that it can correctly
> >implement the constexpr constructor without performance penalties
> >otherwise...
> 
> I don't speak C++, but a grep-based guess coupled with common sense suggests
> that libstdc++ is fine because it doesn't use PTHREAD_MUTEX_INITIALIZER.

It is spelled __GTHREAD_MUTEX_INIT or something like that and goes via
another layer of indirection. Without it, the constexpr version would
need another flag bit, see above about runtime penalty.

Joerg