On Sun, 4 Dec 2022, 11:08 Iain Sandoe via Libstdc++, <libstd...@gcc.gnu.org> wrote:
> While looking at Darwin's os_defines, I wondered whether > _GTHREAD_USE_RECURSIVE_MUTEX_INIT_FUNC was really still necessary. On > checking > the OS, it seems that it was a transient problem that only appears in > Darwin11. > Earlier versions do not have the initializer, and the operation is fixed in > Darwin12+. So, I figure we still need the workaround for Darwin8-11 but > not > later versions (patch implements this). > > Testing on both earlier and later systems does not (as one might expect) > reveal > any differences (we still have some lock-related tests that 'twinkle' so > that > there can be something still hidden by that). > > Anyway. the question is. "is there any reason not to use the system > version of > this where it works, or should I just leave the status quo?" If the > former, > then "ok for master?". > Using the initializer seems preferable when it works, so ok for master, thanks. > thanks > Iain > > -- >8 -- > > The problem described in pr 51906 was fixed in the next OS release. Limit > the > workaround to systems that need it. > > Signed-off-by: Iain Sandoe <i...@sandoe.co.uk> > > libstdc++-v3/ChangeLog: > > * config/os/bsd/darwin/os_defines.h > (_GTHREAD_USE_RECURSIVE_MUTEX_INIT_FUNC): Limit use of this macro > to OS versions that need it. > --- > libstdc++-v3/config/os/bsd/darwin/os_defines.h | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/libstdc++-v3/config/os/bsd/darwin/os_defines.h > b/libstdc++-v3/config/os/bsd/darwin/os_defines.h > index 38fdfb5f6f0..5b611d32e0d 100644 > --- a/libstdc++-v3/config/os/bsd/darwin/os_defines.h > +++ b/libstdc++-v3/config/os/bsd/darwin/os_defines.h > @@ -39,8 +39,12 @@ > // implementation is not itself a weak definition). > #define _GLIBCXX_WEAK_DEFINITION __attribute__ ((__weak__)) > > -// Static initializer macro is buggy in darwin, see libstdc++/51906 > +#if defined (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) \ > + && (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1080) > +// Static initializer macro is absent for Darwin < 11 and buggy in Darwin > 11, > +// see libstdc++/51906. Fixed in Darwin 12 (OS X 10.8). > #define _GTHREAD_USE_RECURSIVE_MUTEX_INIT_FUNC > +#endif > > // Configure checks for nanosleep fail on Darwin, but nanosleep and > // sched_yield are always available, so use them. > -- > 2.37.1 (Apple Git-137.1) > >
