[PATCH] revised fix for nanosleep check in GLIBCXX_ENABLE_LIBSTDCXX_TIME for darwin

[Jack Howarth]

On Thu, Oct 11, 2012 at 06:46:47PM +0100, Jonathan Wakely wrote:
> On 11 October 2012 17:05, Jack Howarth wrote:
> >
> > Jonathan,
> >     The committed patch results in the expected this_thread::yield() and this_thread::sleep_for()
> > support. I did run into a regression at -m32/-m64 on darwin10 (but not darwin11/12).
> >
> > WARNING: program timed out.
> > FAIL: 30_threads/condition_variable/54185.cc execution test
> 
> That's PR 54407, so not a regression.

Jonathan,
   Thanks, I missed that. The pthreads support is definitely improved in darwin11 and later.
           Jack

> 
> > This actually isn't that surprising because the pthread support is buggy on darwin10. We always randomly
> > fail the execution test for 20_util/shared_ptr/thread/default_weaktoshared.cc on darwin10. I filed that
> > as radr://7905357, "testcase 20_util/shared_ptr/thread/default_weaktoshared.cc thread handling bug" back
> > in 2010 and it was fixed in darwin11. Either we tolerate this regression on darwin10 or we can
> > add something like...
> >
> > Index: libstdc++-v3/config/os/bsd/darwin/os_defines.h
> > ===================================================================
> > --- libstdc++-v3/config/os/bsd/darwin/os_defines.h      (revision 192370)
> > +++ libstdc++-v3/config/os/bsd/darwin/os_defines.h      (working copy)
> > @@ -43,8 +43,10 @@
> >  #define _GTHREAD_USE_RECURSIVE_MUTEX_INIT_FUNC
> >
> >  // Configure checks for nanosleep fail on Darwin, but nanosleep and
> > -// sched_yield are always available, so use them.
> > +// sched_yield are always available, so use them 10.6 or later.
> > +#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1060
> >  #define _GLIBCXX_USE_NANOSLEEP 1
> >  #define _GLIBCXX_USE_SCHED_YIELD 1
> > +#endif
> >
> >  #endif
> >
> > Hopefully Mike can chime in with an opinion here. I'll test this workaround later today on darwin10.
> 
> I don't think that will make any difference, because that test was
> already failing anyway.