On Mon, Nov 06, 2023 at 11:52:08AM +0000, Richard Biener wrote:
> The following makes the C++98 locale init path follow the way the
> C++11 performs initialization. This way we deal with pthread_once
> failing, falling back to non-threadsafe initialization which, given we
> initialize from the library, should be serialized by the dynamic
> loader already.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, OK for trunk?
> And GCC 13 branch?
>
> Thanks,
> Richard.
>
> PR libstdc++/112351
> libstdc++-v3/
> * src/c++98/locale.cc (locale::facet::_S_get_c_locale):
> Always perform non-threadsafe init when threadsafe init
> failed.
> ---
> libstdc++-v3/src/c++98/locale.cc | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/libstdc++-v3/src/c++98/locale.cc
> b/libstdc++-v3/src/c++98/locale.cc
> index d308140bab7..e9bec1db3b6 100644
> --- a/libstdc++-v3/src/c++98/locale.cc
> +++ b/libstdc++-v3/src/c++98/locale.cc
> @@ -216,12 +216,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> #ifdef __GTHREADS
> if (__gthread_active_p())
> __gthread_once(&_S_once, _S_initialize_once);
> - else
> #endif
> - {
> - if (!_S_c_locale)
> - _S_initialize_once();
> - }
> + if (__builtin_expect (!_S_c_locale, 0))
> + _S_initialize_once();
> return _S_c_locale;
Wouldn't it be better to just test __gthread_once return value
#ifdef __THREADS
if ((!__gthread_active_p()
|| __gthread_once(&_S_once, _S_initialize_once)))
#endif
if (!_S_c_locale)
_S_initialize_once();
?
Jakub
