/* * ZeroTier One - Network Virtualization Everywhere * Copyright (C) 2011-2018 ZeroTier, Inc. https://www.zerotier.com/ * * This program 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. * * This program 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 this program. If not, see <http://www.gnu.org/licenses/>. * * -- * * You can be released from the requirements of the license by purchasing * a commercial license. Buying such a license is mandatory as soon as you * develop commercial closed-source software that incorporates or links * directly against ZeroTier software without disclosing the source code * of your own application. */ #ifndef ZT_BLOCKINGQUEUE_HPP #define ZT_BLOCKINGQUEUE_HPP #include <queue> #include <mutex> #include <condition_variable> #include <chrono> namespace ZeroTier { /** * Simple C++11 thread-safe queue * * Do not use in node/ since we have not gone C++11 there yet. */ template <class T> class BlockingQueue { public: BlockingQueue(void) : r(true) {} inline void post(T t) { std::lock_guard<std::mutex> lock(m); q.push(t); c.notify_one(); } inline void stop(void) { std::lock_guard<std::mutex> lock(m); r = false; c.notify_all(); } inline bool get(T &value) { std::unique_lock<std::mutex> lock(m); if (!r) return false; while (q.empty()) { c.wait(lock); if (!r) return false; } value = q.front(); q.pop(); return true; } enum TimedWaitResult { OK, TIMED_OUT, STOP }; inline TimedWaitResult get(T &value,const unsigned long ms) { const std::chrono::milliseconds ms2{ms}; std::unique_lock<std::mutex> lock(m); if (!r) return STOP; while (q.empty()) { if (c.wait_for(lock,ms2) == std::cv_status::timeout) return ((r) ? TIMED_OUT : STOP); else if (!r) return STOP; } value = q.front(); q.pop(); return OK; } private: volatile bool r; std::queue<T> q; std::mutex m; std::condition_variable c; }; } // namespace ZeroTier #endif