https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78552
Bug ID: 78552
Summary: std::locale::classic() Needless Race
Product: gcc
Version: 6.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: gccbza at bluematt dot me
Target Milestone: ---
I'm not sure whether the standard has any thread-safety requirements for
std::local::classic() (I cant seem to find any?), but it seems needlessly
race-y:
classic() constructs a new locale on top of the global c_locale using the
locale(_Impl*) constructor, which only bothers to set _M_impl to the pointer
passed in. Thus, every time you call classic() it sets c_locale._M_impl to
_S_classic and then returns a const reference to c_locale.
This isnt an issue on many (any?) platforms, but helgrind/drd gets very upset
and there is seemingly no reason to do this outside of _S_initialize?
