dolphin/Source/Core/Common/Timer.cpp
2022-08-06 22:25:30 -07:00

123 lines
3 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include "Common/Timer.h"
#include <chrono>
#ifdef _WIN32
#include <Windows.h>
#include <ctime>
#include <timeapi.h>
#else
#include <sys/time.h>
#endif
#include "Common/CommonTypes.h"
namespace Common
{
template <typename Clock, typename Duration>
static typename Clock::rep time_now()
{
return std::chrono::time_point_cast<Duration>(Clock::now()).time_since_epoch().count();
}
template <typename Duration>
static auto steady_time_now()
{
return time_now<std::chrono::steady_clock, Duration>();
}
u64 Timer::NowUs()
{
return steady_time_now<std::chrono::microseconds>();
}
u64 Timer::NowMs()
{
return steady_time_now<std::chrono::milliseconds>();
}
void Timer::Start()
{
m_start_ms = NowMs();
m_end_ms = 0;
m_running = true;
}
void Timer::StartWithOffset(u64 offset)
{
Start();
m_start_ms -= offset;
}
void Timer::Stop()
{
m_end_ms = NowMs();
m_running = false;
}
u64 Timer::ElapsedMs() const
{
const u64 end = m_running ? NowMs() : m_end_ms;
// Can handle up to 1 rollover event (underflow produces correct result)
// If Start() has never been called, will return 0
return end - m_start_ms;
}
u64 Timer::GetLocalTimeSinceJan1970()
{
// TODO Would really, really like to use std::chrono here, but Windows did not support
// std::chrono::current_zone() until 19H1, and other compilers don't even provide support for
// timezone-related parts of chrono. Someday!
// see https://bugs.dolphin-emu.org/issues/13007#note-4
time_t sysTime, tzDiff, tzDST;
time(&sysTime);
tm* gmTime = localtime(&sysTime);
// Account for DST where needed
if (gmTime->tm_isdst == 1)
tzDST = 3600;
else
tzDST = 0;
// Lazy way to get local time in sec
gmTime = gmtime(&sysTime);
tzDiff = sysTime - mktime(gmTime);
return static_cast<u64>(sysTime + tzDiff + tzDST);
}
void Timer::IncreaseResolution()
{
#ifdef _WIN32
// Disable execution speed and timer resolution throttling process-wide.
// This mainly will keep Dolphin marked as high performance if it's in the background. The OS
// should make it high performance if it's in the foreground anyway (or for some specific
// threads e.g. audio).
// This is best-effort (i.e. the call may fail on older versions of Windows, where such throttling
// doesn't exist, anyway), and we don't bother reverting once set.
// This adjusts behavior on CPUs with "performance" and "efficiency" cores
PROCESS_POWER_THROTTLING_STATE PowerThrottling{};
PowerThrottling.Version = PROCESS_POWER_THROTTLING_CURRENT_VERSION;
PowerThrottling.ControlMask =
PROCESS_POWER_THROTTLING_EXECUTION_SPEED | PROCESS_POWER_THROTTLING_IGNORE_TIMER_RESOLUTION;
PowerThrottling.StateMask = 0;
SetProcessInformation(GetCurrentProcess(), ProcessPowerThrottling, &PowerThrottling,
sizeof(PowerThrottling));
// Not actually sure how useful this is these days.. :')
timeBeginPeriod(1);
#endif
}
void Timer::RestoreResolution()
{
#ifdef _WIN32
timeEndPeriod(1);
#endif
}
} // Namespace Common