// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <functional>
#include <memory>
#include <mutex>
#include <optional>
#include <string>
#include <thread>
#include <vector>
#include "common/common_types.h"
#include "common/wall_clock.h"
namespace Core::Timing {
/// A callback that may be scheduled for a particular core timing event.
using TimedCallback = std::function<std::optional<std::chrono::nanoseconds>(
std::uintptr_t user_data, s64 time, std::chrono::nanoseconds ns_late)>;
using PauseCallback = std::function<void(bool paused)>;
/// Contains the characteristics of a particular event.
struct EventType {
explicit 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 s64 ns_late that the callbacks get is how many ns late it was.
* So to schedule a new event on a regular basis:
* inside callback:
* ScheduleEvent(period_in_ns - ns_late, 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(std::function<void()>&& on_thread_init_);
/// Tears down all timing related functionality.
void Shutdown();
/// Sets if emulation is multicore or single core, must be set before Initialize
void SetMulticore(bool is_multicore_) {
is_multicore = is_multicore_;
}
/// Check if it's using host timing.
bool IsHostTiming() const {
return is_multicore;
}
/// 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(std::chrono::nanoseconds ns_into_future,
const std::shared_ptr<EventType>& event_type, std::uintptr_t user_data = 0,
bool absolute_time = false);
/// Schedules an event which will automatically re-schedule itself with the given time, until
/// unscheduled
void ScheduleLoopingEvent(std::chrono::nanoseconds start_time,
std::chrono::nanoseconds resched_time,
const std::shared_ptr<EventType>& event_type,
std::uintptr_t user_data = 0, bool absolute_time = false);
void UnscheduleEvent(const std::shared_ptr<EventType>& event_type, std::uintptr_t user_data);
/// 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(u64 ticks_to_add);
void ResetTicks();
void Idle();
s64 GetDowncount() const {
return downcount;
}
/// 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<s64> Advance();
/// Register a callback function to be called when coretiming pauses.
void RegisterPauseCallback(PauseCallback&& callback);
private:
struct Event;
/// Clear all pending events. This should ONLY be done on exit.
void ClearPendingEvents();
static void ThreadEntry(CoreTiming& instance, size_t id);
void ThreadLoop();
std::unique_ptr<Common::WallClock> clock;
s64 global_timer = 0;
// 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::atomic<size_t> pending_events{};
std::shared_ptr<EventType> ev_lost;
std::atomic<bool> has_started{};
std::function<void()> on_thread_init{};
std::vector<std::thread> worker_threads;
std::condition_variable event_cv;
std::condition_variable wait_pause_cv;
std::condition_variable wait_signal_cv;
mutable std::mutex event_mutex;
std::atomic<bool> paused_state{};
bool is_paused{};
bool shutting_down{};
bool is_multicore{};
size_t pause_count{};
s64 pause_end_time{};
/// Cycle timing
u64 ticks{};
s64 downcount{};
std::vector<PauseCallback> pause_callbacks{};
};
/// 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::Timing
