Implement a MultiLevelQueue

This commit is contained in:
Fernando Sahmkow 2019-03-15 22:50:57 -04:00 committed by FernandoS27
parent 47f2405ab1
commit 522957f9f3
3 changed files with 349 additions and 0 deletions

View file

@ -98,6 +98,7 @@ add_library(common STATIC
microprofile.h microprofile.h
microprofileui.h microprofileui.h
misc.cpp misc.cpp
multi_level_queue.h
page_table.cpp page_table.cpp
page_table.h page_table.h
param_package.cpp param_package.cpp

View file

@ -58,4 +58,23 @@ inline u64 CountLeadingZeroes64(u64 value) {
return __builtin_clzll(value); return __builtin_clzll(value);
} }
#endif #endif
inline u32 CountTrailingZeroes32(u32 value) {
u32 count = 0;
while (((value >> count) & 0xf) == 0 && count < 32)
count += 4;
while (((value >> count) & 1) == 0 && count < 32)
count++;
return count;
}
inline u64 CountTrailingZeroes64(u64 value) {
u64 count = 0;
while (((value >> count) & 0xf) == 0 && count < 64)
count += 4;
while (((value >> count) & 1) == 0 && count < 64)
count++;
return count;
}
} // namespace Common } // namespace Common

View file

@ -0,0 +1,329 @@
// Copyright 2019 TuxSH
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <array>
#include <iterator>
#include <list>
#include "common/bit_util.h"
#include "common/common_types.h"
namespace Common {
template <typename T, std::size_t Depth>
class MultiLevelQueue {
public:
using value_type = T;
using reference = value_type&;
using const_reference = const value_type&;
using pointer = value_type*;
using const_pointer = const value_type*;
using difference_type = typename std::pointer_traits<pointer>::difference_type;
using size_type = std::size_t;
template <bool is_constant>
class iterator_impl {
public:
using iterator_category = std::bidirectional_iterator_tag;
using value_type = T;
using pointer = std::conditional_t<is_constant, T*, const T*>;
using reference = std::conditional_t<is_constant, const T&, T&>;
using difference_type = typename std::pointer_traits<pointer>::difference_type;
friend bool operator==(const iterator_impl& lhs, const iterator_impl& rhs) {
return (lhs.IsEnd() && rhs.IsEnd()) || lhs.it == rhs.it;
}
friend bool operator!=(const iterator_impl& lhs, const iterator_impl& rhs) {
return !operator==(lhs, rhs);
}
reference operator*() const {
return *it;
}
pointer operator->() const {
return it.operator->();
}
iterator_impl& operator++() {
if (IsEnd()) {
return *this;
}
++it;
if (it == GetEndItForPrio()) {
u64 prios = mlq.used_priorities;
prios &= ~((1ULL << (current_priority + 1)) - 1);
if (prios == 0) {
current_priority = mlq.depth();
} else {
current_priority = CountTrailingZeroes64(prios);
it = GetBeginItForPrio();
}
}
return *this;
}
iterator_impl& operator--() {
if (IsEnd()) {
if (mlq.used_priorities != 0) {
current_priority = 63 - CountLeadingZeroes64(mlq.used_priorities);
it = GetEndItForPrio();
--it;
}
} else if (it == GetBeginItForPrio()) {
u64 prios = mlq.used_priorities;
prios &= (1ULL << current_priority) - 1;
if (prios != 0) {
current_priority = CountTrailingZeroes64(prios);
it = GetEndItForPrio();
--it;
}
} else {
--it;
}
return *this;
}
iterator_impl operator++(int) {
const iterator_impl v{*this};
++(*this);
return v;
}
iterator_impl operator--(int) {
const iterator_impl v{*this};
--(*this);
return v;
}
// allow implicit const->non-const
iterator_impl(const iterator_impl<false>& other)
: mlq(other.mlq), it(other.it), current_priority(other.current_priority) {}
iterator_impl& operator=(const iterator_impl<false>& other) {
mlq = other.mlq;
it = other.it;
current_priority = other.current_priority;
return *this;
}
friend class iterator_impl<true>;
iterator_impl() = default;
private:
friend class MultiLevelQueue;
using container_ref =
std::conditional_t<is_constant, const MultiLevelQueue&, MultiLevelQueue&>;
using list_iterator = std::conditional_t<is_constant, typename std::list<T>::const_iterator,
typename std::list<T>::iterator>;
explicit iterator_impl(container_ref mlq, list_iterator it, u32 current_priority)
: mlq(mlq), it(it), current_priority(current_priority) {}
explicit iterator_impl(container_ref mlq, u32 current_priority)
: mlq(mlq), it(), current_priority(current_priority) {}
bool IsEnd() const {
return current_priority == mlq.depth();
}
list_iterator GetBeginItForPrio() const {
return mlq.levels[current_priority].begin();
}
list_iterator GetEndItForPrio() const {
return mlq.levels[current_priority].end();
}
container_ref mlq;
list_iterator it;
u32 current_priority;
};
using iterator = iterator_impl<false>;
using const_iterator = iterator_impl<true>;
void add(T& element, u32 priority, bool send_back = true) {
if (send_back)
levels[priority].push_back(element);
else
levels[priority].push_front(element);
used_priorities |= 1ULL << priority;
}
void remove(const T& element, u32 priority) {
levels[priority].erase(ListIterateTo(levels[priority], element));
if (levels[priority].empty()) {
used_priorities &= ~(1ULL << priority);
}
}
void adjust(const T& element, u32 old_priority, u32 new_priority, bool adjust_front = false) {
const auto new_next =
adjust_front ? levels[new_priority].cbegin() : levels[new_priority].cend();
ListSplice(levels[new_priority], new_next, levels[old_priority],
ListIterateTo(levels[old_priority], element));
used_priorities |= 1ULL << new_priority;
if (levels[old_priority].empty()) {
used_priorities &= ~(1ULL << old_priority);
}
}
void adjust(const_iterator it, u32 old_priority, u32 new_priority, bool adjust_front = false) {
adjust(*it, old_priority, new_priority, adjust_front);
}
void transfer_to_front(const T& element, u32 priority, MultiLevelQueue& other) {
ListSplice(other.levels[priority], other.levels[priority].begin(), levels[priority],
ListIterateTo(levels[priority], element));
other.used_priorities |= 1ULL << priority;
if (levels[priority].empty()) {
used_priorities &= ~(1ULL << priority);
}
}
void transfer_to_front(const_iterator it, u32 priority, MultiLevelQueue& other) {
transfer_to_front(*it, priority, other);
}
void transfer_to_back(const T& element, u32 priority, MultiLevelQueue& other) {
ListSplice(other.levels[priority], other.levels[priority].end(), levels[priority],
ListIterateTo(levels[priority], element));
other.used_priorities |= 1ULL << priority;
if (levels[priority].empty()) {
used_priorities &= ~(1ULL << priority);
}
}
void transfer_to_back(const_iterator it, u32 priority, MultiLevelQueue& other) {
transfer_to_back(*it, priority, other);
}
void yield(u32 priority, std::size_t n = 1) {
ListShiftForward(levels[priority], n);
}
std::size_t depth() const {
return Depth;
}
std::size_t size(u32 priority) const {
return levels[priority].size();
}
std::size_t size() const {
u64 priorities = used_priorities;
std::size_t size = 0;
while (priorities != 0) {
const u64 current_priority = CountTrailingZeroes64(priorities);
size += levels[current_priority].size();
priorities &= ~(1ULL << current_priority);
}
return size;
}
bool empty() const {
return used_priorities == 0;
}
bool empty(u32 priority) const {
return (used_priorities & (1ULL << priority)) == 0;
}
u32 highest_priority_set(u32 max_priority = 0) const {
const u64 priorities =
max_priority == 0 ? used_priorities : (used_priorities & ~((1ULL << max_priority) - 1));
return priorities == 0 ? Depth : static_cast<u32>(CountTrailingZeroes64(priorities));
}
u32 lowest_priority_set(u32 min_priority = Depth - 1) const {
const u64 priorities = min_priority >= Depth - 1
? used_priorities
: (used_priorities & ((1ULL << (min_priority + 1)) - 1));
return priorities == 0 ? Depth : 63 - CountLeadingZeroes64(priorities);
}
const_iterator cbegin(u32 max_prio = 0) const {
const u32 priority = highest_priority_set(max_prio);
return priority == Depth ? cend()
: const_iterator{*this, levels[priority].cbegin(), priority};
}
const_iterator begin(u32 max_prio = 0) const {
return cbegin(max_prio);
}
iterator begin(u32 max_prio = 0) {
const u32 priority = highest_priority_set(max_prio);
return priority == Depth ? end() : iterator{*this, levels[priority].begin(), priority};
}
const_iterator cend(u32 min_prio = Depth - 1) const {
return min_prio == Depth - 1 ? const_iterator{*this, Depth} : cbegin(min_prio + 1);
}
const_iterator end(u32 min_prio = Depth - 1) const {
return cend(min_prio);
}
iterator end(u32 min_prio = Depth - 1) {
return min_prio == Depth - 1 ? iterator{*this, Depth} : begin(min_prio + 1);
}
T& front(u32 max_priority = 0) {
const u32 priority = highest_priority_set(max_priority);
return levels[priority == Depth ? 0 : priority].front();
}
const T& front(u32 max_priority = 0) const {
const u32 priority = highest_priority_set(max_priority);
return levels[priority == Depth ? 0 : priority].front();
}
T back(u32 min_priority = Depth - 1) {
const u32 priority = lowest_priority_set(min_priority); // intended
return levels[priority == Depth ? 63 : priority].back();
}
const T& back(u32 min_priority = Depth - 1) const {
const u32 priority = lowest_priority_set(min_priority); // intended
return levels[priority == Depth ? 63 : priority].back();
}
private:
using const_list_iterator = typename std::list<T>::const_iterator;
static void ListShiftForward(std::list<T>& list, const std::size_t shift = 1) {
// NOTE: May want to consider making this an assertion or something
if (shift >= list.size()) {
return;
}
const auto begin_range = list.begin();
const auto end_range = std::next(begin_range, shift);
list.splice(list.end(), list, begin_range, end_range);
}
static void ListSplice(std::list<T>& in_list, const_list_iterator position,
std::list<T>& out_list, const_list_iterator element) {
in_list.splice(position, out_list, element);
}
static const_list_iterator ListIterateTo(const std::list<T>& list, const T& element) {
auto it = list.cbegin();
while (it != list.cend() && *it != element) {
++it;
}
return it;
}
std::array<std::list<T>, Depth> levels;
u64 used_priorities = 0;
};
} // namespace Common