suyu/src/core/core_timing.cpp
Lioncash bd983414f6 core_timing: Convert core timing into a class
Gets rid of the largest set of mutable global state within the core.
This also paves a way for eliminating usages of GetInstance() on the
System class as a follow-up.

Note that no behavioral changes have been made, and this simply extracts
the functionality into a class. This also has the benefit of making
dependencies on the core timing functionality explicit within the
relevant interfaces.
2019-02-15 21:50:25 -05:00

216 lines
6.9 KiB
C++

// Copyright 2008 Dolphin Emulator Project / 2017 Citra Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include "core/core_timing.h"
#include <algorithm>
#include <mutex>
#include <string>
#include <tuple>
#include "common/assert.h"
#include "common/thread.h"
#include "core/core_timing_util.h"
namespace Core::Timing {
constexpr int MAX_SLICE_LENGTH = 20000;
struct CoreTiming::Event {
s64 time;
u64 fifo_order;
u64 userdata;
const EventType* type;
// Sort by time, unless the times are the same, in which case sort by
// the order added to the queue
friend bool operator>(const Event& left, const Event& right) {
return std::tie(left.time, left.fifo_order) > std::tie(right.time, right.fifo_order);
}
friend bool operator<(const Event& left, const Event& right) {
return std::tie(left.time, left.fifo_order) < std::tie(right.time, right.fifo_order);
}
};
CoreTiming::CoreTiming() = default;
CoreTiming::~CoreTiming() = default;
void CoreTiming::Initialize() {
downcount = MAX_SLICE_LENGTH;
slice_length = MAX_SLICE_LENGTH;
global_timer = 0;
idled_cycles = 0;
// The time between CoreTiming being initialized and the first call to Advance() is considered
// the slice boundary between slice -1 and slice 0. Dispatcher loops must call Advance() before
// executing the first cycle of each slice to prepare the slice length and downcount for
// that slice.
is_global_timer_sane = true;
event_fifo_id = 0;
const auto empty_timed_callback = [](u64, s64) {};
ev_lost = RegisterEvent("_lost_event", empty_timed_callback);
}
void CoreTiming::Shutdown() {
MoveEvents();
ClearPendingEvents();
UnregisterAllEvents();
}
EventType* CoreTiming::RegisterEvent(const std::string& name, TimedCallback callback) {
// check for existing type with same name.
// we want event type names to remain unique so that we can use them for serialization.
ASSERT_MSG(event_types.find(name) == event_types.end(),
"CoreTiming Event \"{}\" is already registered. Events should only be registered "
"during Init to avoid breaking save states.",
name.c_str());
auto info = event_types.emplace(name, EventType{callback, nullptr});
EventType* event_type = &info.first->second;
event_type->name = &info.first->first;
return event_type;
}
void CoreTiming::UnregisterAllEvents() {
ASSERT_MSG(event_queue.empty(), "Cannot unregister events with events pending");
event_types.clear();
}
void CoreTiming::ScheduleEvent(s64 cycles_into_future, const EventType* event_type, u64 userdata) {
ASSERT(event_type != nullptr);
const s64 timeout = GetTicks() + cycles_into_future;
// If this event needs to be scheduled before the next advance(), force one early
if (!is_global_timer_sane) {
ForceExceptionCheck(cycles_into_future);
}
event_queue.emplace_back(Event{timeout, event_fifo_id++, userdata, event_type});
std::push_heap(event_queue.begin(), event_queue.end(), std::greater<>());
}
void CoreTiming::ScheduleEventThreadsafe(s64 cycles_into_future, const EventType* event_type,
u64 userdata) {
ts_queue.Push(Event{global_timer + cycles_into_future, 0, userdata, event_type});
}
void CoreTiming::UnscheduleEvent(const EventType* event_type, u64 userdata) {
const auto itr = std::remove_if(event_queue.begin(), event_queue.end(), [&](const Event& e) {
return e.type == event_type && e.userdata == userdata;
});
// Removing random items breaks the invariant so we have to re-establish it.
if (itr != event_queue.end()) {
event_queue.erase(itr, event_queue.end());
std::make_heap(event_queue.begin(), event_queue.end(), std::greater<>());
}
}
void CoreTiming::UnscheduleEventThreadsafe(const EventType* event_type, u64 userdata) {
unschedule_queue.Push(std::make_pair(event_type, userdata));
}
u64 CoreTiming::GetTicks() const {
u64 ticks = static_cast<u64>(global_timer);
if (!is_global_timer_sane) {
ticks += slice_length - downcount;
}
return ticks;
}
u64 CoreTiming::GetIdleTicks() const {
return static_cast<u64>(idled_cycles);
}
void CoreTiming::AddTicks(u64 ticks) {
downcount -= static_cast<int>(ticks);
}
void CoreTiming::ClearPendingEvents() {
event_queue.clear();
}
void CoreTiming::RemoveEvent(const EventType* event_type) {
const auto itr = std::remove_if(event_queue.begin(), event_queue.end(),
[&](const Event& e) { return e.type == event_type; });
// Removing random items breaks the invariant so we have to re-establish it.
if (itr != event_queue.end()) {
event_queue.erase(itr, event_queue.end());
std::make_heap(event_queue.begin(), event_queue.end(), std::greater<>());
}
}
void CoreTiming::RemoveNormalAndThreadsafeEvent(const EventType* event_type) {
MoveEvents();
RemoveEvent(event_type);
}
void CoreTiming::ForceExceptionCheck(s64 cycles) {
cycles = std::max<s64>(0, cycles);
if (downcount <= cycles) {
return;
}
// downcount is always (much) smaller than MAX_INT so we can safely cast cycles to an int
// here. Account for cycles already executed by adjusting the g.slice_length
slice_length -= downcount - static_cast<int>(cycles);
downcount = static_cast<int>(cycles);
}
void CoreTiming::MoveEvents() {
for (Event ev; ts_queue.Pop(ev);) {
ev.fifo_order = event_fifo_id++;
event_queue.emplace_back(std::move(ev));
std::push_heap(event_queue.begin(), event_queue.end(), std::greater<>());
}
}
void CoreTiming::Advance() {
MoveEvents();
for (std::pair<const EventType*, u64> ev; unschedule_queue.Pop(ev);) {
UnscheduleEvent(ev.first, ev.second);
}
const int cycles_executed = slice_length - downcount;
global_timer += cycles_executed;
slice_length = MAX_SLICE_LENGTH;
is_global_timer_sane = true;
while (!event_queue.empty() && event_queue.front().time <= global_timer) {
Event evt = std::move(event_queue.front());
std::pop_heap(event_queue.begin(), event_queue.end(), std::greater<>());
event_queue.pop_back();
evt.type->callback(evt.userdata, static_cast<int>(global_timer - evt.time));
}
is_global_timer_sane = false;
// Still events left (scheduled in the future)
if (!event_queue.empty()) {
slice_length = static_cast<int>(
std::min<s64>(event_queue.front().time - global_timer, MAX_SLICE_LENGTH));
}
downcount = slice_length;
}
void CoreTiming::Idle() {
idled_cycles += downcount;
downcount = 0;
}
std::chrono::microseconds CoreTiming::GetGlobalTimeUs() const {
return std::chrono::microseconds{GetTicks() * 1000000 / BASE_CLOCK_RATE};
}
int CoreTiming::GetDowncount() const {
return downcount;
}
} // namespace Core::Timing