suyu/src/core/core_timing.cpp
Lioncash f0bfb24c61 threadsafe_queue: Remove NeedSize template parameter
The necessity of this parameter is dubious at best, and in 2019 probably
offers completely negligible savings as opposed to just leaving this
enabled. This removes it and simplifies the overall interface.
2019-02-12 22:09:51 -05:00

245 lines
7.9 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 <unordered_map>
#include <vector>
#include "common/assert.h"
#include "common/thread.h"
#include "common/threadsafe_queue.h"
#include "core/core_timing_util.h"
namespace Core::Timing {
static s64 global_timer;
static int slice_length;
static int downcount;
struct EventType {
TimedCallback callback;
const std::string* name;
};
struct 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
static bool operator>(const Event& left, const Event& right) {
return std::tie(left.time, left.fifo_order) > std::tie(right.time, right.fifo_order);
}
static bool operator<(const Event& left, const Event& right) {
return std::tie(left.time, left.fifo_order) < std::tie(right.time, right.fifo_order);
}
// unordered_map stores each element separately as a linked list node so pointers to elements
// remain stable regardless of rehashes/resizing.
static std::unordered_map<std::string, EventType> event_types;
// 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.
static std::vector<Event> event_queue;
static u64 event_fifo_id;
// the queue for storing the events from other threads threadsafe until they will be added
// to the event_queue by the emu thread
static Common::MPSCQueue<Event> ts_queue;
// the queue for unscheduling the events from other threads threadsafe
static Common::MPSCQueue<std::pair<const EventType*, u64>> unschedule_queue;
constexpr int MAX_SLICE_LENGTH = 20000;
static s64 idled_cycles;
// Are we in a function that has been called from Advance()
// If events are sheduled from a function that gets called from Advance(),
// don't change slice_length and downcount.
static bool is_global_timer_sane;
static EventType* ev_lost = nullptr;
static void EmptyTimedCallback(u64 userdata, s64 cyclesLate) {}
EventType* 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 UnregisterAllEvents() {
ASSERT_MSG(event_queue.empty(), "Cannot unregister events with events pending");
event_types.clear();
}
void Init() {
downcount = MAX_SLICE_LENGTH;
slice_length = MAX_SLICE_LENGTH;
global_timer = 0;
idled_cycles = 0;
// The time between CoreTiming being intialized 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;
ev_lost = RegisterEvent("_lost_event", &EmptyTimedCallback);
}
void Shutdown() {
MoveEvents();
ClearPendingEvents();
UnregisterAllEvents();
}
// This should only be called from the CPU thread. If you are calling
// it from any other thread, you are doing something evil
u64 GetTicks() {
u64 ticks = static_cast<u64>(global_timer);
if (!is_global_timer_sane) {
ticks += slice_length - downcount;
}
return ticks;
}
void AddTicks(u64 ticks) {
downcount -= static_cast<int>(ticks);
}
u64 GetIdleTicks() {
return static_cast<u64>(idled_cycles);
}
void ClearPendingEvents() {
event_queue.clear();
}
void ScheduleEvent(s64 cycles_into_future, const EventType* event_type, u64 userdata) {
ASSERT(event_type != nullptr);
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 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 UnscheduleEvent(const EventType* event_type, u64 userdata) {
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 UnscheduleEventThreadsafe(const EventType* event_type, u64 userdata) {
unschedule_queue.Push(std::make_pair(event_type, userdata));
}
void RemoveEvent(const EventType* event_type) {
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 RemoveNormalAndThreadsafeEvent(const EventType* event_type) {
MoveEvents();
RemoveEvent(event_type);
}
void ForceExceptionCheck(s64 cycles) {
cycles = std::max<s64>(0, cycles);
if (downcount > cycles) {
// 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 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 Advance() {
MoveEvents();
for (std::pair<const EventType*, u64> ev; unschedule_queue.Pop(ev);) {
UnscheduleEvent(ev.first, ev.second);
}
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 Idle() {
idled_cycles += downcount;
downcount = 0;
}
std::chrono::microseconds GetGlobalTimeUs() {
return std::chrono::microseconds{GetTicks() * 1000000 / BASE_CLOCK_RATE};
}
int GetDowncount() {
return downcount;
}
} // namespace Core::Timing