diff --git a/src/common/steady_clock.cpp b/src/common/steady_clock.cpp
index 7828591960..9415eed29b 100644
--- a/src/common/steady_clock.cpp
+++ b/src/common/steady_clock.cpp
@@ -28,13 +28,12 @@ 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;
+ static constexpr s64 WindowsEpochToUnixEpoch = 0x19DB1DED53E8000LL;
FILETIME filetime;
GetSystemTimePreciseAsFileTime(&filetime);
return Multiplier * ((static_cast<s64>(filetime.dwHighDateTime) << 32) +
- static_cast<s64>(filetime.dwLowDateTime)) -
- WindowsEpochToUnixEpochNS;
+ static_cast<s64>(filetime.dwLowDateTime) - WindowsEpochToUnixEpoch);
}
#endif
diff --git a/src/common/wall_clock.cpp b/src/common/wall_clock.cpp
index 817e71d52f..ad8db06b08 100644
--- a/src/common/wall_clock.cpp
+++ b/src/common/wall_clock.cpp
@@ -2,88 +2,71 @@
// SPDX-License-Identifier: GPL-2.0-or-later
#include "common/steady_clock.h"
-#include "common/uint128.h"
#include "common/wall_clock.h"
#ifdef ARCHITECTURE_x86_64
#include "common/x64/cpu_detect.h"
#include "common/x64/native_clock.h"
+#include "common/x64/rdtsc.h"
#endif
namespace Common {
class StandardWallClock final : public WallClock {
public:
- explicit StandardWallClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequency_)
- : WallClock{emulated_cpu_frequency_, emulated_clock_frequency_, false},
- start_time{SteadyClock::Now()} {}
+ explicit StandardWallClock() : start_time{SteadyClock::Now()} {}
- std::chrono::nanoseconds GetTimeNS() override {
+ std::chrono::nanoseconds GetTimeNS() const override {
return SteadyClock::Now() - start_time;
}
- std::chrono::microseconds GetTimeUS() override {
- return std::chrono::duration_cast<std::chrono::microseconds>(GetTimeNS());
+ std::chrono::microseconds GetTimeUS() const override {
+ return static_cast<std::chrono::microseconds>(GetHostTicksElapsed() / NsToUsRatio::den);
}
- std::chrono::milliseconds GetTimeMS() override {
- return std::chrono::duration_cast<std::chrono::milliseconds>(GetTimeNS());
+ std::chrono::milliseconds GetTimeMS() const override {
+ return static_cast<std::chrono::milliseconds>(GetHostTicksElapsed() / NsToMsRatio::den);
}
- u64 GetClockCycles() override {
- const u128 temp = Common::Multiply64Into128(GetTimeNS().count(), emulated_clock_frequency);
- return Common::Divide128On32(temp, NS_RATIO).first;
+ u64 GetCNTPCT() const override {
+ return GetHostTicksElapsed() * NsToCNTPCTRatio::num / NsToCNTPCTRatio::den;
}
- u64 GetCPUCycles() override {
- const u128 temp = Common::Multiply64Into128(GetTimeNS().count(), emulated_cpu_frequency);
- return Common::Divide128On32(temp, NS_RATIO).first;
+ u64 GetHostTicksNow() const override {
+ return static_cast<u64>(SteadyClock::Now().time_since_epoch().count());
}
- void Pause([[maybe_unused]] bool is_paused) override {
- // Do nothing in this clock type.
+ u64 GetHostTicksElapsed() const override {
+ return static_cast<u64>(GetTimeNS().count());
+ }
+
+ bool IsNative() const override {
+ return false;
}
private:
SteadyClock::time_point start_time;
};
+std::unique_ptr<WallClock> CreateOptimalClock() {
#ifdef ARCHITECTURE_x86_64
-
-std::unique_ptr<WallClock> CreateBestMatchingClock(u64 emulated_cpu_frequency,
- u64 emulated_clock_frequency) {
const auto& caps = GetCPUCaps();
- u64 rtsc_frequency = 0;
- if (caps.invariant_tsc) {
- rtsc_frequency = caps.tsc_frequency ? caps.tsc_frequency : EstimateRDTSCFrequency();
- }
- // Fallback to StandardWallClock if the hardware TSC does not have the precision greater than:
- // - A nanosecond
- // - The emulated CPU frequency
- // - The emulated clock counter frequency (CNTFRQ)
- if (rtsc_frequency <= WallClock::NS_RATIO || rtsc_frequency <= emulated_cpu_frequency ||
- rtsc_frequency <= emulated_clock_frequency) {
- return std::make_unique<StandardWallClock>(emulated_cpu_frequency,
- emulated_clock_frequency);
+ if (caps.invariant_tsc && caps.tsc_frequency >= WallClock::CNTFRQ) {
+ return std::make_unique<X64::NativeClock>(caps.tsc_frequency);
} else {
- return std::make_unique<X64::NativeClock>(emulated_cpu_frequency, emulated_clock_frequency,
- rtsc_frequency);
+ // Fallback to StandardWallClock if the hardware TSC
+ // - Is not invariant
+ // - Is not more precise than CNTFRQ
+ return std::make_unique<StandardWallClock>();
}
-}
-
#else
-
-std::unique_ptr<WallClock> CreateBestMatchingClock(u64 emulated_cpu_frequency,
- u64 emulated_clock_frequency) {
- return std::make_unique<StandardWallClock>(emulated_cpu_frequency, emulated_clock_frequency);
+ return std::make_unique<StandardWallClock>();
+#endif
}
-#endif
-
-std::unique_ptr<WallClock> CreateStandardWallClock(u64 emulated_cpu_frequency,
- u64 emulated_clock_frequency) {
- return std::make_unique<StandardWallClock>(emulated_cpu_frequency, emulated_clock_frequency);
+std::unique_ptr<WallClock> CreateStandardWallClock() {
+ return std::make_unique<StandardWallClock>();
}
} // namespace Common
diff --git a/src/common/wall_clock.h b/src/common/wall_clock.h
index 157ec5eaea..a73e6e6443 100644
--- a/src/common/wall_clock.h
+++ b/src/common/wall_clock.h
@@ -5,6 +5,7 @@
#include <chrono>
#include <memory>
+#include <ratio>
#include "common/common_types.h"
@@ -12,50 +13,43 @@ namespace Common {
class WallClock {
public:
- static constexpr u64 NS_RATIO = 1'000'000'000;
- static constexpr u64 US_RATIO = 1'000'000;
- static constexpr u64 MS_RATIO = 1'000;
+ static constexpr u64 CNTFRQ = 19'200'000; // CNTPCT_EL0 Frequency = 19.2 MHz
virtual ~WallClock() = default;
- /// Returns current wall time in nanoseconds
- [[nodiscard]] virtual std::chrono::nanoseconds GetTimeNS() = 0;
+ /// @returns The time in nanoseconds since the construction of this clock.
+ virtual std::chrono::nanoseconds GetTimeNS() const = 0;
- /// Returns current wall time in microseconds
- [[nodiscard]] virtual std::chrono::microseconds GetTimeUS() = 0;
+ /// @returns The time in microseconds since the construction of this clock.
+ virtual std::chrono::microseconds GetTimeUS() const = 0;
- /// Returns current wall time in milliseconds
- [[nodiscard]] virtual std::chrono::milliseconds GetTimeMS() = 0;
+ /// @returns The time in milliseconds since the construction of this clock.
+ virtual std::chrono::milliseconds GetTimeMS() const = 0;
- /// Returns current wall time in emulated clock cycles
- [[nodiscard]] virtual u64 GetClockCycles() = 0;
+ /// @returns The guest CNTPCT ticks since the construction of this clock.
+ virtual u64 GetCNTPCT() const = 0;
- /// Returns current wall time in emulated cpu cycles
- [[nodiscard]] virtual u64 GetCPUCycles() = 0;
+ /// @returns The raw host timer ticks since an indeterminate epoch.
+ virtual u64 GetHostTicksNow() const = 0;
- virtual void Pause(bool is_paused) = 0;
+ /// @returns The raw host timer ticks since the construction of this clock.
+ virtual u64 GetHostTicksElapsed() const = 0;
- /// Tells if the wall clock, uses the host CPU's hardware clock
- [[nodiscard]] bool IsNative() const {
- return is_native;
- }
+ /// @returns Whether the clock directly uses the host's hardware clock.
+ virtual bool IsNative() const = 0;
protected:
- explicit WallClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequency_, bool is_native_)
- : emulated_cpu_frequency{emulated_cpu_frequency_},
- emulated_clock_frequency{emulated_clock_frequency_}, is_native{is_native_} {}
+ using NsRatio = std::nano;
+ using UsRatio = std::micro;
+ using MsRatio = std::milli;
- u64 emulated_cpu_frequency;
- u64 emulated_clock_frequency;
-
-private:
- bool is_native;
+ using NsToUsRatio = std::ratio_divide<std::nano, std::micro>;
+ using NsToMsRatio = std::ratio_divide<std::nano, std::milli>;
+ using NsToCNTPCTRatio = std::ratio<CNTFRQ, std::nano::den>;
};
-[[nodiscard]] std::unique_ptr<WallClock> CreateBestMatchingClock(u64 emulated_cpu_frequency,
- u64 emulated_clock_frequency);
+std::unique_ptr<WallClock> CreateOptimalClock();
-[[nodiscard]] std::unique_ptr<WallClock> CreateStandardWallClock(u64 emulated_cpu_frequency,
- u64 emulated_clock_frequency);
+std::unique_ptr<WallClock> CreateStandardWallClock();
} // namespace Common
diff --git a/src/common/x64/native_clock.cpp b/src/common/x64/native_clock.cpp
index 277b006625..5d1eb05907 100644
--- a/src/common/x64/native_clock.cpp
+++ b/src/common/x64/native_clock.cpp
@@ -1,164 +1,45 @@
// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
-#include <array>
-#include <chrono>
-#include <thread>
-
-#include "common/atomic_ops.h"
-#include "common/steady_clock.h"
#include "common/uint128.h"
#include "common/x64/native_clock.h"
+#include "common/x64/rdtsc.h"
-#ifdef _MSC_VER
-#include <intrin.h>
-#endif
+namespace Common::X64 {
-namespace Common {
+NativeClock::NativeClock(u64 rdtsc_frequency_)
+ : start_ticks{FencedRDTSC()}, rdtsc_frequency{rdtsc_frequency_},
+ ns_rdtsc_factor{GetFixedPoint64Factor(NsRatio::den, rdtsc_frequency)},
+ us_rdtsc_factor{GetFixedPoint64Factor(UsRatio::den, rdtsc_frequency)},
+ ms_rdtsc_factor{GetFixedPoint64Factor(MsRatio::den, rdtsc_frequency)},
+ cntpct_rdtsc_factor{GetFixedPoint64Factor(CNTFRQ, rdtsc_frequency)} {}
-#ifdef _MSC_VER
-__forceinline static u64 FencedRDTSC() {
- _mm_lfence();
- _ReadWriteBarrier();
- const u64 result = __rdtsc();
- _mm_lfence();
- _ReadWriteBarrier();
- return result;
-}
-#else
-static u64 FencedRDTSC() {
- u64 eax;
- u64 edx;
- asm volatile("lfence\n\t"
- "rdtsc\n\t"
- "lfence\n\t"
- : "=a"(eax), "=d"(edx));
- return (edx << 32) | eax;
-}
-#endif
-
-template <u64 Nearest>
-static u64 RoundToNearest(u64 value) {
- const auto mod = value % Nearest;
- return mod >= (Nearest / 2) ? (value - mod + Nearest) : (value - mod);
+std::chrono::nanoseconds NativeClock::GetTimeNS() const {
+ return std::chrono::nanoseconds{MultiplyHigh(GetHostTicksElapsed(), ns_rdtsc_factor)};
}
-u64 EstimateRDTSCFrequency() {
- // Discard the first result measuring the rdtsc.
- FencedRDTSC();
- std::this_thread::sleep_for(std::chrono::milliseconds{1});
- FencedRDTSC();
-
- // Get the current time.
- const auto start_time = Common::RealTimeClock::Now();
- const u64 tsc_start = FencedRDTSC();
- // Wait for 250 milliseconds.
- std::this_thread::sleep_for(std::chrono::milliseconds{250});
- const auto end_time = Common::RealTimeClock::Now();
- const u64 tsc_end = FencedRDTSC();
- // Calculate differences.
- const u64 timer_diff = static_cast<u64>(
- std::chrono::duration_cast<std::chrono::nanoseconds>(end_time - start_time).count());
- const u64 tsc_diff = tsc_end - tsc_start;
- const u64 tsc_freq = MultiplyAndDivide64(tsc_diff, 1000000000ULL, timer_diff);
- return RoundToNearest<1000>(tsc_freq);
+std::chrono::microseconds NativeClock::GetTimeUS() const {
+ return std::chrono::microseconds{MultiplyHigh(GetHostTicksElapsed(), us_rdtsc_factor)};
}
-namespace X64 {
-NativeClock::NativeClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequency_,
- u64 rtsc_frequency_)
- : WallClock(emulated_cpu_frequency_, emulated_clock_frequency_, true), rtsc_frequency{
- rtsc_frequency_} {
- // Thread to re-adjust the RDTSC frequency after 10 seconds has elapsed.
- time_sync_thread = std::jthread{[this](std::stop_token token) {
- // Get the current time.
- const auto start_time = Common::RealTimeClock::Now();
- const u64 tsc_start = FencedRDTSC();
- // Wait for 10 seconds.
- if (!Common::StoppableTimedWait(token, std::chrono::seconds{10})) {
- return;
- }
- const auto end_time = Common::RealTimeClock::Now();
- const u64 tsc_end = FencedRDTSC();
- // Calculate differences.
- const u64 timer_diff = static_cast<u64>(
- std::chrono::duration_cast<std::chrono::nanoseconds>(end_time - start_time).count());
- const u64 tsc_diff = tsc_end - tsc_start;
- const u64 tsc_freq = MultiplyAndDivide64(tsc_diff, 1000000000ULL, timer_diff);
- rtsc_frequency = tsc_freq;
- CalculateAndSetFactors();
- }};
-
- time_point.inner.last_measure = FencedRDTSC();
- time_point.inner.accumulated_ticks = 0U;
- CalculateAndSetFactors();
+std::chrono::milliseconds NativeClock::GetTimeMS() const {
+ return std::chrono::milliseconds{MultiplyHigh(GetHostTicksElapsed(), ms_rdtsc_factor)};
}
-u64 NativeClock::GetRTSC() {
- TimePoint new_time_point{};
- TimePoint current_time_point{};
-
- current_time_point.pack = Common::AtomicLoad128(time_point.pack.data());
- do {
- const u64 current_measure = FencedRDTSC();
- u64 diff = current_measure - current_time_point.inner.last_measure;
- diff = diff & ~static_cast<u64>(static_cast<s64>(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));
- return new_time_point.inner.accumulated_ticks;
+u64 NativeClock::GetCNTPCT() const {
+ return MultiplyHigh(GetHostTicksElapsed(), cntpct_rdtsc_factor);
}
-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());
- 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));
- }
+u64 NativeClock::GetHostTicksNow() const {
+ return FencedRDTSC();
}
-std::chrono::nanoseconds NativeClock::GetTimeNS() {
- const u64 rtsc_value = GetRTSC();
- return std::chrono::nanoseconds{MultiplyHigh(rtsc_value, ns_rtsc_factor)};
+u64 NativeClock::GetHostTicksElapsed() const {
+ return FencedRDTSC() - start_ticks;
}
-std::chrono::microseconds NativeClock::GetTimeUS() {
- const u64 rtsc_value = GetRTSC();
- return std::chrono::microseconds{MultiplyHigh(rtsc_value, us_rtsc_factor)};
+bool NativeClock::IsNative() const {
+ return true;
}
-std::chrono::milliseconds NativeClock::GetTimeMS() {
- const u64 rtsc_value = GetRTSC();
- return std::chrono::milliseconds{MultiplyHigh(rtsc_value, ms_rtsc_factor)};
-}
-
-u64 NativeClock::GetClockCycles() {
- const u64 rtsc_value = GetRTSC();
- return MultiplyHigh(rtsc_value, clock_rtsc_factor);
-}
-
-u64 NativeClock::GetCPUCycles() {
- const u64 rtsc_value = GetRTSC();
- return MultiplyHigh(rtsc_value, cpu_rtsc_factor);
-}
-
-void NativeClock::CalculateAndSetFactors() {
- ns_rtsc_factor = GetFixedPoint64Factor(NS_RATIO, rtsc_frequency);
- us_rtsc_factor = GetFixedPoint64Factor(US_RATIO, rtsc_frequency);
- ms_rtsc_factor = GetFixedPoint64Factor(MS_RATIO, rtsc_frequency);
- clock_rtsc_factor = GetFixedPoint64Factor(emulated_clock_frequency, rtsc_frequency);
- cpu_rtsc_factor = GetFixedPoint64Factor(emulated_cpu_frequency, rtsc_frequency);
-}
-
-} // namespace X64
-
-} // namespace Common
+} // namespace Common::X64
diff --git a/src/common/x64/native_clock.h b/src/common/x64/native_clock.h
index 03ca291d80..d6f8626c1e 100644
--- a/src/common/x64/native_clock.h
+++ b/src/common/x64/native_clock.h
@@ -3,58 +3,36 @@
#pragma once
-#include "common/polyfill_thread.h"
#include "common/wall_clock.h"
-namespace Common {
+namespace Common::X64 {
-namespace X64 {
class NativeClock final : public WallClock {
public:
- explicit NativeClock(u64 emulated_cpu_frequency_, u64 emulated_clock_frequency_,
- u64 rtsc_frequency_);
+ explicit NativeClock(u64 rdtsc_frequency_);
- std::chrono::nanoseconds GetTimeNS() override;
+ std::chrono::nanoseconds GetTimeNS() const override;
- std::chrono::microseconds GetTimeUS() override;
+ std::chrono::microseconds GetTimeUS() const override;
- std::chrono::milliseconds GetTimeMS() override;
+ std::chrono::milliseconds GetTimeMS() const override;
- u64 GetClockCycles() override;
+ u64 GetCNTPCT() const override;
- u64 GetCPUCycles() override;
+ u64 GetHostTicksNow() const override;
- void Pause(bool is_paused) override;
+ u64 GetHostTicksElapsed() const override;
+
+ bool IsNative() const override;
private:
- u64 GetRTSC();
+ u64 start_ticks;
+ u64 rdtsc_frequency;
- void CalculateAndSetFactors();
-
- union alignas(16) TimePoint {
- TimePoint() : pack{} {}
- u128 pack{};
- struct Inner {
- u64 last_measure{};
- u64 accumulated_ticks{};
- } inner;
- };
-
- TimePoint time_point;
-
- // factors
- u64 clock_rtsc_factor{};
- u64 cpu_rtsc_factor{};
- u64 ns_rtsc_factor{};
- u64 us_rtsc_factor{};
- u64 ms_rtsc_factor{};
-
- u64 rtsc_frequency;
-
- std::jthread time_sync_thread;
+ u64 ns_rdtsc_factor;
+ u64 us_rdtsc_factor;
+ u64 ms_rdtsc_factor;
+ u64 cntpct_rdtsc_factor;
};
-} // namespace X64
-u64 EstimateRDTSCFrequency();
-
-} // namespace Common
+} // namespace Common::X64