early-access version 2254

This commit is contained in:
pineappleEA
2021-11-29 04:02:55 +01:00
parent bd6cfd7191
commit b159b8b7aa
9 changed files with 89 additions and 146 deletions

View File

@@ -44,14 +44,12 @@ 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_} {
TimePoint new_time_point{};
_mm_mfence();
new_time_point.last_measure = __rdtsc();
new_time_point.accumulated_ticks = 0U;
time_point.store(new_time_point);
ns_rtsc_factor = GetFixedPoint64Factor(1000'000'000ULL, rtsc_frequency);
us_rtsc_factor = GetFixedPoint64Factor(1000'000ULL, rtsc_frequency);
ms_rtsc_factor = GetFixedPoint64Factor(1000ULL, rtsc_frequency);
time_point.inner.last_measure = __rdtsc();
time_point.inner.accumulated_ticks = 0U;
ns_rtsc_factor = GetFixedPoint64Factor(1000000000, rtsc_frequency);
us_rtsc_factor = GetFixedPoint64Factor(1000000, rtsc_frequency);
ms_rtsc_factor = GetFixedPoint64Factor(1000, rtsc_frequency);
clock_rtsc_factor = GetFixedPoint64Factor(emulated_clock_frequency, rtsc_frequency);
cpu_rtsc_factor = GetFixedPoint64Factor(emulated_cpu_frequency, rtsc_frequency);
}
@@ -60,19 +58,19 @@ u64 NativeClock::GetRTSC() {
TimePoint new_time_point{};
TimePoint current_time_point{};
do {
current_time_point = time_point.load(std::memory_order_acquire);
current_time_point.pack = time_point.pack;
_mm_mfence();
const u64 current_measure = __rdtsc();
u64 diff = current_measure - current_time_point.last_measure;
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.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_relaxed));
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));
/// The clock cannot be more precise than the guest timer, remove the lower bits
return new_time_point.accumulated_ticks & inaccuracy_mask;
return new_time_point.inner.accumulated_ticks & inaccuracy_mask;
}
void NativeClock::Pause(bool is_paused) {
@@ -80,13 +78,12 @@ void NativeClock::Pause(bool is_paused) {
TimePoint current_time_point{};
TimePoint new_time_point{};
do {
current_time_point = time_point.load(std::memory_order_acquire);
new_time_point = current_time_point;
current_time_point.pack = time_point.pack;
new_time_point.pack = current_time_point.pack;
_mm_mfence();
new_time_point.last_measure = __rdtsc();
} while (!time_point.compare_exchange_weak(current_time_point, new_time_point,
std::memory_order_release,
std::memory_order_relaxed));
new_time_point.inner.last_measure = __rdtsc();
} while (!Common::AtomicCompareAndSwap(time_point.pack.data(), new_time_point.pack,
current_time_point.pack));
}
}

View File

@@ -4,7 +4,6 @@
#pragma once
#include <atomic>
#include <optional>
#include "common/wall_clock.h"
@@ -32,9 +31,13 @@ public:
private:
u64 GetRTSC();
struct alignas(16) TimePoint {
u64 last_measure{};
u64 accumulated_ticks{};
union alignas(16) TimePoint {
TimePoint() : pack{} {}
u128 pack{};
struct Inner {
u64 last_measure{};
u64 accumulated_ticks{};
} inner;
};
/// value used to reduce the native clocks accuracy as some apss rely on
@@ -42,7 +45,7 @@ private:
/// be higher.
static constexpr u64 inaccuracy_mask = ~(UINT64_C(0x400) - 1);
std::atomic<TimePoint> time_point;
TimePoint time_point;
// factors
u64 clock_rtsc_factor{};
u64 cpu_rtsc_factor{};