aboutsummaryrefslogtreecommitdiff
path: root/src/core/core_timing.h
blob: 7e4dff7f3dd50649c87fc29e662261b655c91689 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#pragma once

#include <atomic>
#include <chrono>
#include <functional>
#include <memory>
#include <mutex>
#include <optional>
#include <string>
#include <thread>

#include <boost/heap/fibonacci_heap.hpp>

#include "common/common_types.h"
#include "common/thread.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>(
    s64 time, std::chrono::nanoseconds ns_late)>;

/// Contains the characteristics of a particular event.
struct EventType {
    explicit EventType(TimedCallback&& callback_, std::string&& name_)
        : callback{std::move(callback_)}, name{std::move(name_)}, sequence_number{0} {}

    /// The event's callback function.
    TimedCallback callback;
    /// A pointer to the name of the event.
    const std::string name;
    /// A monotonic sequence number, incremented when this event is
    /// changed externally.
    size_t sequence_number;
};

enum class UnscheduleEventType {
    Wait,
    NoWait,
};

/**
 * 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_);

    /// Clear all pending events. This should ONLY be done on exit.
    void ClearPendingEvents();

    /// Sets if emulation is multicore or single core, must be set before Initialize
    void SetMulticore(bool is_multicore_) {
        is_multicore = 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, 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,
                              bool absolute_time = false);

    void UnscheduleEvent(const std::shared_ptr<EventType>& event_type,
                         UnscheduleEventType type = UnscheduleEventType::Wait);

    void AddTicks(u64 ticks_to_add);

    void ResetTicks();

    void Idle();

    s64 GetDowncount() const {
        return downcount;
    }

    /// Returns the current CNTPCT tick value.
    u64 GetClockTicks() const;

    /// Returns the current GPU tick value.
    u64 GetGPUTicks() 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();

#ifdef _WIN32
    void SetTimerResolutionNs(std::chrono::nanoseconds ns);
#endif

private:
    struct Event;

    static void ThreadEntry(CoreTiming& instance);
    void ThreadLoop();

    void Reset();

    std::unique_ptr<Common::WallClock> clock;

    s64 global_timer = 0;

#ifdef _WIN32
    s64 timer_resolution_ns;
#endif

    using heap_t =
        boost::heap::fibonacci_heap<CoreTiming::Event, boost::heap::compare<std::greater<>>>;

    heap_t event_queue;
    u64 event_fifo_id = 0;

    Common::Event event{};
    Common::Event pause_event{};
    mutable std::mutex basic_lock;
    std::mutex advance_lock;
    std::unique_ptr<std::jthread> 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::function<void()> on_thread_init{};

    bool is_multicore{};
    s64 pause_end_time{};

    /// Cycle timing
    u64 cpu_ticks{};
    s64 downcount{};
};

/// 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