suyu/src/core/host_timing.h
2020-06-18 16:29:23 -04:00

160 lines
5 KiB
C++

// Copyright 2020 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <atomic>
#include <chrono>
#include <functional>
#include <memory>
#include <mutex>
#include <optional>
#include <string>
#include <thread>
#include <vector>
#include "common/common_types.h"
#include "common/spin_lock.h"
#include "common/thread.h"
#include "common/threadsafe_queue.h"
#include "common/wall_clock.h"
#include "core/hardware_properties.h"
namespace Core::HostTiming {
/// A callback that may be scheduled for a particular core timing event.
using TimedCallback = std::function<void(u64 userdata, s64 cycles_late)>;
/// Contains the characteristics of a particular event.
struct EventType {
EventType(TimedCallback&& callback, std::string&& name)
: callback{std::move(callback)}, name{std::move(name)} {}
/// The event's callback function.
TimedCallback callback;
/// A pointer to the name of the event.
const std::string name;
};
/**
* This is a system to schedule events into the emulated machine's future. Time is measured
* in main CPU clock cycles.
*
* To schedule an event, you first have to register its type. This is where you pass in the
* callback. You then schedule events using the type id you get back.
*
* The int cyclesLate that the callbacks get is how many cycles late it was.
* So to schedule a new event on a regular basis:
* inside callback:
* ScheduleEvent(periodInCycles - cyclesLate, callback, "whatever")
*/
class CoreTiming {
public:
CoreTiming();
~CoreTiming();
CoreTiming(const CoreTiming&) = delete;
CoreTiming(CoreTiming&&) = delete;
CoreTiming& operator=(const CoreTiming&) = delete;
CoreTiming& operator=(CoreTiming&&) = delete;
/// CoreTiming begins at the boundary of timing slice -1. An initial call to Advance() is
/// required to end slice - 1 and start slice 0 before the first cycle of code is executed.
void Initialize();
/// Tears down all timing related functionality.
void Shutdown();
/// Pauses/Unpauses the execution of the timer thread.
void Pause(bool is_paused);
/// Pauses/Unpauses the execution of the timer thread and waits until paused.
void SyncPause(bool is_paused);
/// Checks if core timing is running.
bool IsRunning() const;
/// Checks if the timer thread has started.
bool HasStarted() const {
return has_started;
}
/// Checks if there are any pending time events.
bool HasPendingEvents() const;
/// Schedules an event in core timing
void ScheduleEvent(s64 ns_into_future, const std::shared_ptr<EventType>& event_type,
u64 userdata = 0);
void UnscheduleEvent(const std::shared_ptr<EventType>& event_type, u64 userdata);
/// We only permit one event of each type in the queue at a time.
void RemoveEvent(const std::shared_ptr<EventType>& event_type);
void AddTicks(std::size_t core_index, u64 ticks);
void ResetTicks(std::size_t core_index);
/// Returns current time in emulated CPU cycles
u64 GetCPUTicks() const;
/// Returns current time in emulated in Clock cycles
u64 GetClockTicks() const;
/// Returns current time in microseconds.
std::chrono::microseconds GetGlobalTimeUs() const;
/// Returns current time in nanoseconds.
std::chrono::nanoseconds GetGlobalTimeNs() const;
/// Checks for events manually and returns time in nanoseconds for next event, threadsafe.
std::optional<u64> Advance();
private:
struct Event;
/// Clear all pending events. This should ONLY be done on exit.
void ClearPendingEvents();
static void ThreadEntry(CoreTiming& instance);
void ThreadLoop();
std::unique_ptr<Common::WallClock> clock;
u64 global_timer = 0;
std::chrono::nanoseconds start_point;
// The queue is a min-heap using std::make_heap/push_heap/pop_heap.
// We don't use std::priority_queue because we need to be able to serialize, unserialize and
// erase arbitrary events (RemoveEvent()) regardless of the queue order. These aren't
// accomodated by the standard adaptor class.
std::vector<Event> event_queue;
u64 event_fifo_id = 0;
std::shared_ptr<EventType> ev_lost;
Common::Event event{};
Common::SpinLock basic_lock{};
Common::SpinLock advance_lock{};
std::unique_ptr<std::thread> timer_thread;
std::atomic<bool> paused{};
std::atomic<bool> paused_set{};
std::atomic<bool> wait_set{};
std::atomic<bool> shutting_down{};
std::atomic<bool> has_started{};
std::array<std::atomic<u64>, Core::Hardware::NUM_CPU_CORES> ticks_count{};
};
/// Creates a core timing event with the given name and callback.
///
/// @param name The name of the core timing event to create.
/// @param callback The callback to execute for the event.
///
/// @returns An EventType instance representing the created event.
///
std::shared_ptr<EventType> CreateEvent(std::string name, TimedCallback&& callback);
} // namespace Core::HostTiming