diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 43ae8a9e7..850ce8006 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -98,6 +98,7 @@ add_library(common STATIC
microprofile.h
microprofileui.h
misc.cpp
+ multi_level_queue.h
page_table.cpp
page_table.h
param_package.cpp
diff --git a/src/common/bit_util.h b/src/common/bit_util.h
index 1eea17ba1..14e53c273 100644
--- a/src/common/bit_util.h
+++ b/src/common/bit_util.h
@@ -58,4 +58,23 @@ inline u64 CountLeadingZeroes64(u64 value) {
return __builtin_clzll(value);
}
#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
diff --git a/src/common/multi_level_queue.h b/src/common/multi_level_queue.h
new file mode 100644
index 000000000..fc72a8238
--- /dev/null
+++ b/src/common/multi_level_queue.h
@@ -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