// 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 = 10000;
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() {
for (std::size_t core = 0; core < num_cpu_cores; core++) {
downcounts[core] = MAX_SLICE_LENGTH;
time_slice[core] = MAX_SLICE_LENGTH;
}
slice_length = MAX_SLICE_LENGTH;
global_timer = 0;
idled_cycles = 0;
current_context = 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() {
ClearPendingEvents();
UnregisterAllEvents();
}
EventType* CoreTiming::RegisterEvent(const std::string& name, TimedCallback callback) {
std::lock_guard guard{inner_mutex};
// 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);
std::lock_guard guard{inner_mutex};
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::UnscheduleEvent(const EventType* event_type, u64 userdata) {
std::lock_guard guard{inner_mutex};
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<>());
}
}
u64 CoreTiming::GetTicks() const {
u64 ticks = static_cast<u64>(global_timer);
if (!is_global_timer_sane) {
ticks += time_slice[current_context] - downcounts[current_context];
}
return ticks;
}
u64 CoreTiming::GetIdleTicks() const {
return static_cast<u64>(idled_cycles);
}
void CoreTiming::AddTicks(u64 ticks) {
downcounts[current_context] -= static_cast<s64>(ticks);
}
void CoreTiming::ClearPendingEvents() {
event_queue.clear();
}
void CoreTiming::RemoveEvent(const EventType* event_type) {
std::lock_guard guard{inner_mutex};
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::ForceExceptionCheck(s64 cycles) {
cycles = std::max<s64>(0, cycles);
if (downcounts[current_context] <= 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 -= downcounts[current_context] - static_cast<int>(cycles);
downcounts[current_context] = static_cast<int>(cycles);
}
std::optional<u64> CoreTiming::NextAvailableCore(const s64 needed_ticks) const {
const u64 original_context = current_context;
u64 next_context = (original_context + 1) % num_cpu_cores;
while (next_context != original_context) {
if (time_slice[next_context] >= needed_ticks) {
return {next_context};
} else if (time_slice[next_context] >= 0) {
return {};
}
next_context = (next_context + 1) % num_cpu_cores;
}
return {};
}
void CoreTiming::Advance() {
std::unique_lock<std::mutex> guard(inner_mutex);
const int cycles_executed = time_slice[current_context] - downcounts[current_context];
time_slice[current_context] = std::max<s64>(0, downcounts[current_context]);
global_timer += cycles_executed;
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();
inner_mutex.unlock();
evt.type->callback(evt.userdata, global_timer - evt.time);
inner_mutex.lock();
}
is_global_timer_sane = false;
// Still events left (scheduled in the future)
if (!event_queue.empty()) {
s64 needed_ticks = std::min<s64>(event_queue.front().time - global_timer, MAX_SLICE_LENGTH);
const auto next_core = NextAvailableCore(needed_ticks);
if (next_core) {
downcounts[*next_core] = needed_ticks;
}
}
downcounts[current_context] = time_slice[current_context];
}
void CoreTiming::ResetRun() {
for (std::size_t core = 0; core < num_cpu_cores; core++) {
downcounts[core] = MAX_SLICE_LENGTH;
time_slice[core] = MAX_SLICE_LENGTH;
}
current_context = 0;
// Still events left (scheduled in the future)
if (!event_queue.empty()) {
s64 needed_ticks = std::min<s64>(event_queue.front().time - global_timer, MAX_SLICE_LENGTH);
downcounts[current_context] = needed_ticks;
}
}
void CoreTiming::Idle() {
idled_cycles += downcounts[current_context];
downcounts[current_context] = 0;
}
std::chrono::microseconds CoreTiming::GetGlobalTimeUs() const {
return std::chrono::microseconds{GetTicks() * 1000000 / BASE_CLOCK_RATE};
}
s64 CoreTiming::GetDowncount() const {
return downcounts[current_context];
}
} // namespace Core::Timing