concurrentQueue.hpp

/*
 *    Copyright (C) 2019-2021 Joshua Boudreau <jboudreau@45drives.com>
 *
 *    This file is part of autotier.
 *
 *    autotier is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    autotier is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with autotier.  If not, see <https://www.gnu.org/licenses/>.
 */
 
/* Simple concurrent queue implementation. No guard against popping from empty queue.
 * Check empty() before popping. Intended only for multiple producer, single consumer use.
 */
 
#pragma once
 
#include <mutex>
#include <queue>
 
template<class T>
class ConcurrentQueue {
public:
    ConcurrentQueue() : mt_(), queue_() {}
    ~ConcurrentQueue() = default;
    bool empty(void) const {
        return queue_.empty();
    }
    void push(const T &val) {
        std::lock_guard<std::mutex> lk(mt_);
        queue_.push(val);
    }
    template<typename... Args>
    void emplace(Args &&...args) {
        std::lock_guard<std::mutex> lk(mt_);
        queue_.emplace(args...);
    }
    T pop(void) {
        std::lock_guard<std::mutex> lk(mt_);
        T val = queue_.front();
        queue_.pop();
        return val;
    }
private:
    std::mutex mt_;       
    std::queue<T> queue_; 
};