AimRT/install_x64/include/unifex/detail/intrusive_queue.hpp
2025-01-12 19:51:34 +08:00

127 lines
2.9 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* Licensed under the Apache License Version 2.0 with LLVM Exceptions
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* https://llvm.org/LICENSE.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <tuple>
#include <utility>
#include <unifex/detail/prologue.hpp>
namespace unifex {
template <typename Item, Item* Item::*Next>
class intrusive_queue {
public:
intrusive_queue() noexcept = default;
intrusive_queue(intrusive_queue&& other) noexcept
: head_(std::exchange(other.head_, nullptr)),
tail_(std::exchange(other.tail_, nullptr)) {}
intrusive_queue& operator=(intrusive_queue other) noexcept {
std::swap(head_, other.head_);
std::swap(tail_, other.tail_);
return *this;
}
~intrusive_queue() {
UNIFEX_ASSERT(empty());
}
static intrusive_queue make_reversed(Item* list) noexcept {
Item* newHead = nullptr;
Item* newTail = list;
while (list != nullptr) {
Item* next = list->*Next;
list->*Next = newHead;
newHead = list;
list = next;
}
intrusive_queue result;
result.head_ = newHead;
result.tail_ = newTail;
return result;
}
[[nodiscard]] bool empty() const noexcept {
return head_ == nullptr;
}
[[nodiscard]] Item* pop_front() noexcept {
UNIFEX_ASSERT(!empty());
Item* item = std::exchange(head_, head_->*Next);
if (head_ == nullptr) {
tail_ = nullptr;
}
return item;
}
void push_front(Item* item) noexcept {
UNIFEX_ASSERT(item != nullptr);
item->*Next = head_;
head_ = item;
if (tail_ == nullptr) {
tail_ = item;
}
}
void push_back(Item* item) noexcept {
UNIFEX_ASSERT(item != nullptr);
item->*Next = nullptr;
if (tail_ == nullptr) {
head_ = item;
} else {
tail_->*Next = item;
}
tail_ = item;
}
void append(intrusive_queue other) noexcept {
if (other.empty())
return;
auto* otherHead = std::exchange(other.head_, nullptr);
if (empty()) {
head_ = otherHead;
} else {
tail_->*Next = otherHead;
}
tail_ = std::exchange(other.tail_, nullptr);
}
void prepend(intrusive_queue other) noexcept {
if (other.empty())
return;
other.tail_->*Next = head_;
head_ = other.head_;
if (tail_ == nullptr) {
tail_ = other.tail_;
}
other.tail_ = nullptr;
other.head_ = nullptr;
}
private:
Item* head_ = nullptr;
Item* tail_ = nullptr;
};
} // namespace unifex
#include <unifex/detail/epilogue.hpp>