citra/src/common/thread_queue_list.h
Tobias f6b543886c
Port yuzu-emu/yuzu#4528: "common: Make use of [[nodiscard]] where applicable" (#5535)
Co-authored-by: LC <712067+lioncash@users.noreply.github.com>
2020-08-31 21:06:16 +02:00

212 lines
5.7 KiB
C++

// Copyright 2014 Citra Emulator Project / PPSSPP Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <algorithm>
#include <array>
#include <deque>
#include <boost/serialization/deque.hpp>
#include <boost/serialization/split_member.hpp>
#include "common/common_types.h"
namespace Common {
template <class T, unsigned int N>
struct ThreadQueueList {
// TODO(yuriks): If performance proves to be a problem, the std::deques can be replaced with
// (dynamically resizable) circular buffers to remove their overhead when
// inserting and popping.
using Priority = unsigned int;
// Number of priority levels. (Valid levels are [0..NUM_QUEUES).)
static constexpr Priority NUM_QUEUES = N;
ThreadQueueList() {
first = nullptr;
}
// Only for debugging, returns priority level.
[[nodiscard]] Priority contains(const T& uid) const {
for (Priority i = 0; i < NUM_QUEUES; ++i) {
const Queue& cur = queues[i];
if (std::find(cur.data.cbegin(), cur.data.cend(), uid) != cur.data.cend()) {
return i;
}
}
return -1;
}
[[nodiscard]] T get_first() const {
const Queue* cur = first;
while (cur != nullptr) {
if (!cur->data.empty()) {
return cur->data.front();
}
cur = cur->next_nonempty;
}
return T();
}
T pop_first() {
Queue* cur = first;
while (cur != nullptr) {
if (!cur->data.empty()) {
auto tmp = std::move(cur->data.front());
cur->data.pop_front();
return tmp;
}
cur = cur->next_nonempty;
}
return T();
}
T pop_first_better(Priority priority) {
Queue* cur = first;
Queue* stop = &queues[priority];
while (cur < stop) {
if (!cur->data.empty()) {
auto tmp = std::move(cur->data.front());
cur->data.pop_front();
return tmp;
}
cur = cur->next_nonempty;
}
return T();
}
void push_front(Priority priority, const T& thread_id) {
Queue* cur = &queues[priority];
cur->data.push_front(thread_id);
}
void push_back(Priority priority, const T& thread_id) {
Queue* cur = &queues[priority];
cur->data.push_back(thread_id);
}
void move(const T& thread_id, Priority old_priority, Priority new_priority) {
remove(old_priority, thread_id);
prepare(new_priority);
push_back(new_priority, thread_id);
}
void remove(Priority priority, const T& thread_id) {
Queue* const cur = &queues[priority];
const auto iter = std::remove(cur->data.begin(), cur->data.end(), thread_id);
cur->data.erase(iter, cur->data.end());
}
void rotate(Priority priority) {
Queue* cur = &queues[priority];
if (cur->data.size() > 1) {
cur->data.push_back(std::move(cur->data.front()));
cur->data.pop_front();
}
}
void clear() {
queues.fill(Queue());
first = nullptr;
}
[[nodiscard]] bool empty(Priority priority) const {
const Queue* cur = &queues[priority];
return cur->data.empty();
}
void prepare(Priority priority) {
Queue* cur = &queues[priority];
if (cur->next_nonempty == UnlinkedTag())
link(priority);
}
private:
struct Queue {
// Points to the next active priority, skipping over ones that have never been used.
Queue* next_nonempty = UnlinkedTag();
// Double-ended queue of threads in this priority level
std::deque<T> data;
};
/// Special tag used to mark priority levels that have never been used.
static Queue* UnlinkedTag() {
return reinterpret_cast<Queue*>(1);
}
void link(Priority priority) {
Queue* cur = &queues[priority];
for (int i = priority - 1; i >= 0; --i) {
if (queues[i].next_nonempty != UnlinkedTag()) {
cur->next_nonempty = queues[i].next_nonempty;
queues[i].next_nonempty = cur;
return;
}
}
cur->next_nonempty = first;
first = cur;
}
// The first queue that's ever been used.
Queue* first;
// The priority level queues of thread ids.
std::array<Queue, NUM_QUEUES> queues;
s64 ToIndex(const Queue* q) const {
if (q == nullptr) {
return -2;
} else if (q == UnlinkedTag()) {
return -1;
} else {
return q - queues.data();
}
}
Queue* ToPointer(s64 idx) {
if (idx == -1) {
return UnlinkedTag();
} else if (idx < 0) {
return nullptr;
} else {
return &queues[idx];
}
}
friend class boost::serialization::access;
template <class Archive>
void save(Archive& ar, const unsigned int file_version) const {
const s64 idx = ToIndex(first);
ar << idx;
for (std::size_t i = 0; i < NUM_QUEUES; i++) {
const s64 idx1 = ToIndex(queues[i].next_nonempty);
ar << idx1;
ar << queues[i].data;
}
}
template <class Archive>
void load(Archive& ar, const unsigned int file_version) {
s64 idx;
ar >> idx;
first = ToPointer(idx);
for (std::size_t i = 0; i < NUM_QUEUES; i++) {
ar >> idx;
queues[i].next_nonempty = ToPointer(idx);
ar >> queues[i].data;
}
}
BOOST_SERIALIZATION_SPLIT_MEMBER()
};
} // namespace Common