suyu/src/common/wall_clock.h

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// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <chrono>
#include <memory>
#include <ratio>
#include "common/common_types.h"
namespace Common {
class WallClock {
public:
static constexpr u64 CNTFRQ = 19'200'000; // CNTPCT_EL0 Frequency = 19.2 MHz
virtual ~WallClock() = default;
/// @returns The time in nanoseconds since the construction of this clock.
virtual std::chrono::nanoseconds GetTimeNS() const = 0;
/// @returns The time in microseconds since the construction of this clock.
virtual std::chrono::microseconds GetTimeUS() const = 0;
/// @returns The time in milliseconds since the construction of this clock.
virtual std::chrono::milliseconds GetTimeMS() const = 0;
/// @returns The guest CNTPCT ticks since the construction of this clock.
virtual u64 GetCNTPCT() const = 0;
/// @returns The raw host timer ticks since an indeterminate epoch.
virtual u64 GetHostTicksNow() const = 0;
/// @returns The raw host timer ticks since the construction of this clock.
virtual u64 GetHostTicksElapsed() const = 0;
/// @returns Whether the clock directly uses the host's hardware clock.
virtual bool IsNative() const = 0;
static inline u64 NSToCNTPCT(u64 ns) {
return ns * NsToCNTPCTRatio::num / NsToCNTPCTRatio::den;
}
static inline u64 USToCNTPCT(u64 us) {
return us * UsToCNTPCTRatio::num / UsToCNTPCTRatio::den;
}
static inline u64 CNTPCTToNS(u64 cntpct) {
return cntpct * NsToCNTPCTRatio::den / NsToCNTPCTRatio::num;
}
static inline u64 CNTPCTToUS(u64 cntpct) {
return cntpct * UsToCNTPCTRatio::den / UsToCNTPCTRatio::num;
}
protected:
using NsRatio = std::nano;
using UsRatio = std::micro;
using MsRatio = std::milli;
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>;
using UsToCNTPCTRatio = std::ratio<CNTFRQ, std::micro::den>;
};
std::unique_ptr<WallClock> CreateOptimalClock();
std::unique_ptr<WallClock> CreateStandardWallClock();
} // namespace Common