From a Darwin perspective, this LGTM (it's what we're shipping on macOS 10.12 and iOS 10).
Eric, do you have a good idea for how to test this? > On 2016-Dec-05, at 14:36, Bruno Cardoso Lopes via Phabricator > <revi...@reviews.llvm.org> wrote: > > bruno created this revision. > bruno added reviewers: mclow.lists, dexonsmith, EricWF. > bruno added a subscriber: cfe-commits. > > CLOCK_MONOTONIC is only defined on Darwin on libc versions >= 1133 and its > behaviour differs from Linux. CLOCK_UPTIME on Darwin actually matches > CLOCK_MONOTONIC on Linux, due to historical coincidence (Linux doesn't match > POSIX here but Darwin does). Use CLOCK_UPTIME_RAW on Darwin since the _RAW > version gives nanosecond precision and is lower overhead. > > > https://reviews.llvm.org/D27429 > > Files: > src/chrono.cpp > > > Index: src/chrono.cpp > =================================================================== > --- src/chrono.cpp > +++ src/chrono.cpp > @@ -75,8 +75,19 @@ > steady_clock::now() _NOEXCEPT > { > struct timespec tp; > +#if defined(__APPLE__) && defined(CLOCK_UPTIME_RAW) > + // CLOCK_MONOTONIC is only defined on Darwin on libc versions >= 1133 and > + // its behaviour differs from Linux. > + // CLOCK_UPTIME on Darwin actually matches CLOCK_MONOTONIC on Linux, due > to > + // historical coincidence (Linux doesn't match POSIX here but Darwin > does). > + // Use CLOCK_UPTIME_RAW on Darwin since the _RAW version gives nanosecond > + // precision and is lower overhead. > + if (0 != clock_gettime(CLOCK_UPTIME_RAW, &tp)) > + __throw_system_error(errno, "clock_gettime(CLOCK_UPTIME_RAW) > failed"); > +#else > if (0 != clock_gettime(CLOCK_MONOTONIC, &tp)) > __throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC) failed"); > +#endif > return time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec)); > } > > > > <D27429.80328.patch> _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
