From 096366ead51345bcd170e31b6160b14aaf73e996 Mon Sep 17 00:00:00 2001 From: Fernando Sahmkow Date: Tue, 23 Nov 2021 03:29:00 +0100 Subject: Common: improve native clock. --- src/common/x64/native_clock.cpp | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-) (limited to 'src/common/x64/native_clock.cpp') diff --git a/src/common/x64/native_clock.cpp b/src/common/x64/native_clock.cpp index 1b7194503..427a382cd 100644 --- a/src/common/x64/native_clock.cpp +++ b/src/common/x64/native_clock.cpp @@ -5,7 +5,6 @@ #include #include -#include "common/atomic_ops.h" #include "common/uint128.h" #include "common/x64/native_clock.h" @@ -65,8 +64,10 @@ NativeClock::NativeClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequen u64 rtsc_frequency_) : WallClock(emulated_cpu_frequency_, emulated_clock_frequency_, true), rtsc_frequency{ rtsc_frequency_} { - time_point.inner.last_measure = FencedRDTSC(); - time_point.inner.accumulated_ticks = 0U; + TimePoint new_time_point{}; + new_time_point.last_measure = FencedRDTSC(); + new_time_point.accumulated_ticks = 0U; + time_point.store(new_time_point); ns_rtsc_factor = GetFixedPoint64Factor(NS_RATIO, rtsc_frequency); us_rtsc_factor = GetFixedPoint64Factor(US_RATIO, rtsc_frequency); ms_rtsc_factor = GetFixedPoint64Factor(MS_RATIO, rtsc_frequency); @@ -76,34 +77,31 @@ NativeClock::NativeClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequen u64 NativeClock::GetRTSC() { TimePoint new_time_point{}; - TimePoint current_time_point{}; - - current_time_point.pack = Common::AtomicLoad128(time_point.pack.data()); + TimePoint current_time_point = time_point.load(std::memory_order_acquire); do { const u64 current_measure = FencedRDTSC(); - u64 diff = current_measure - current_time_point.inner.last_measure; + u64 diff = current_measure - current_time_point.last_measure; diff = diff & ~static_cast(static_cast(diff) >> 63); // max(diff, 0) - new_time_point.inner.last_measure = current_measure > current_time_point.inner.last_measure - ? current_measure - : current_time_point.inner.last_measure; - new_time_point.inner.accumulated_ticks = current_time_point.inner.accumulated_ticks + diff; - } while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack, - current_time_point.pack, current_time_point.pack)); + new_time_point.last_measure = current_measure > current_time_point.last_measure + ? current_measure + : current_time_point.last_measure; + new_time_point.accumulated_ticks = current_time_point.accumulated_ticks + diff; + } while (!time_point.compare_exchange_weak( + current_time_point, new_time_point, std::memory_order_release, std::memory_order_acquire)); /// The clock cannot be more precise than the guest timer, remove the lower bits - return new_time_point.inner.accumulated_ticks & inaccuracy_mask; + return new_time_point.accumulated_ticks & inaccuracy_mask; } void NativeClock::Pause(bool is_paused) { if (!is_paused) { - TimePoint current_time_point{}; TimePoint new_time_point{}; - - current_time_point.pack = Common::AtomicLoad128(time_point.pack.data()); + TimePoint current_time_point = time_point.load(std::memory_order_acquire); do { - new_time_point.pack = current_time_point.pack; - new_time_point.inner.last_measure = FencedRDTSC(); - } while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack, - current_time_point.pack, current_time_point.pack)); + new_time_point = current_time_point; + new_time_point.last_measure = FencedRDTSC(); + } while (!time_point.compare_exchange_weak(current_time_point, new_time_point, + std::memory_order_release, + std::memory_order_acquire)); } } -- cgit v1.2.3