Panda3DS/third_party/lockfree/spsc/queue.hpp
offtkp 78ac8d2c0d A kissable commit
Minor fixes
2024-07-31 02:06:04 +03:00

110 lines
3.7 KiB
C++
Executable file

/**************************************************************
* @file queue.hpp
* @brief A queue implementation written in standard c++11
* suitable for both low-end microcontrollers all the way
* to HPC machines. Lock-free for single consumer single
* producer scenarios.
**************************************************************/
/**************************************************************
* Copyright (c) 2023 Djordje Nedic
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated
* documentation files (the "Software"), to deal in the Software
* without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to
* whom the Software is furnished to do so, subject to the
* following conditions:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
* KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
* WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* This file is part of lockfree
*
* Author: Djordje Nedic <nedic.djordje2@gmail.com>
* Version: v2.0.8
**************************************************************/
/************************** INCLUDE ***************************/
#ifndef LOCKFREE_QUEUE_HPP
#define LOCKFREE_QUEUE_HPP
#include <atomic>
#include <cstddef>
#include <type_traits>
#if __cplusplus >= 201703L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
#include <optional>
#endif
namespace lockfree {
namespace spsc {
/*************************** TYPES ****************************/
template <typename T, size_t size> class Queue {
static_assert(std::is_trivial<T>::value, "The type T must be trivial");
static_assert(size > 2, "Buffer size must be bigger than 2");
/********************** PUBLIC METHODS ************************/
public:
Queue();
/**
* @brief Adds an element into the queue.
* Should only be called from the producer thread.
* @param[in] element
* @retval Operation success
*/
bool Push(const T &element);
/**
* @brief Removes an element from the queue.
* Should only be called from the consumer thread.
* @param[out] element
* @retval Operation success
*/
bool Pop(T &element);
#if __cplusplus >= 201703L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
/**
* @brief Removes an element from the queue.
* Should only be called from the consumer thread.
* @retval Either the element or nothing
*/
std::optional<T> PopOptional();
#endif
/********************** PRIVATE MEMBERS ***********************/
private:
T _data[size]; /**< Data array */
#if LOCKFREE_CACHE_COHERENT
alignas(LOCKFREE_CACHELINE_LENGTH) std::atomic_size_t _r; /**< Read index */
alignas(
LOCKFREE_CACHELINE_LENGTH) std::atomic_size_t _w; /**< Write index */
#else
std::atomic_size_t _r; /**< Read index */
std::atomic_size_t _w; /**< Write index */
#endif
};
} /* namespace spsc */
} /* namespace lockfree */
/************************** INCLUDE ***************************/
/* Include the implementation */
#include "queue_impl.hpp"
#endif /* LOCKFREE_QUEUE_HPP */