From 6f9918552c6a1d56a21fa544a7776cd1e5af7bc4 Mon Sep 17 00:00:00 2001 From: Morph <39850852+Morph1984@users.noreply.github.com> Date: Sat, 4 Mar 2023 22:59:04 -0500 Subject: [PATCH] steady_clock: Introduce a real time clock --- src/common/steady_clock.cpp | 25 +++++++++++++++++++++++++ src/common/steady_clock.h | 11 +++++++++++ 2 files changed, 36 insertions(+) diff --git a/src/common/steady_clock.cpp b/src/common/steady_clock.cpp index 0d5908aa79..7828591960 100644 --- a/src/common/steady_clock.cpp +++ b/src/common/steady_clock.cpp @@ -23,6 +23,19 @@ static s64 WindowsQueryPerformanceCounter() { QueryPerformanceCounter(&counter); return counter.QuadPart; } + +static s64 GetSystemTimeNS() { + // GetSystemTimePreciseAsFileTime returns the file time in 100ns units. + static constexpr s64 Multiplier = 100; + // Convert Windows epoch to Unix epoch. + static constexpr s64 WindowsEpochToUnixEpochNS = 0x19DB1DED53E8000LL; + + FILETIME filetime; + GetSystemTimePreciseAsFileTime(&filetime); + return Multiplier * ((static_cast(filetime.dwHighDateTime) << 32) + + static_cast(filetime.dwLowDateTime)) - + WindowsEpochToUnixEpochNS; +} #endif SteadyClock::time_point SteadyClock::Now() noexcept { @@ -53,4 +66,16 @@ SteadyClock::time_point SteadyClock::Now() noexcept { #endif } +RealTimeClock::time_point RealTimeClock::Now() noexcept { +#if defined(_WIN32) + return time_point{duration{GetSystemTimeNS()}}; +#elif defined(__APPLE__) + return time_point{duration{clock_gettime_nsec_np(CLOCK_REALTIME)}}; +#else + timespec ts; + clock_gettime(CLOCK_REALTIME, &ts); + return time_point{std::chrono::seconds{ts.tv_sec} + std::chrono::nanoseconds{ts.tv_nsec}}; +#endif +} + }; // namespace Common diff --git a/src/common/steady_clock.h b/src/common/steady_clock.h index 9497cf865d..dbd0e25131 100644 --- a/src/common/steady_clock.h +++ b/src/common/steady_clock.h @@ -20,4 +20,15 @@ struct SteadyClock { [[nodiscard]] static time_point Now() noexcept; }; +struct RealTimeClock { + using rep = s64; + using period = std::nano; + using duration = std::chrono::nanoseconds; + using time_point = std::chrono::time_point; + + static constexpr bool is_steady = false; + + [[nodiscard]] static time_point Now() noexcept; +}; + } // namespace Common