// // detail/scoped_lock.hpp // ~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2011 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #ifndef BOOST_ASIO_DETAIL_SCOPED_LOCK_HPP #define BOOST_ASIO_DETAIL_SCOPED_LOCK_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include <boost/asio/detail/noncopyable.hpp> #include <boost/asio/detail/push_options.hpp> namespace boost { namespace asio { namespace detail { // Helper class to lock and unlock a mutex automatically. template <typename Mutex> class scoped_lock : private noncopyable { public: // Constructor acquires the lock. scoped_lock(Mutex& m) : mutex_(m) { mutex_.lock(); locked_ = true; } // Destructor releases the lock. ~scoped_lock() { if (locked_) mutex_.unlock(); } // Explicitly acquire the lock. void lock() { if (!locked_) { mutex_.lock(); locked_ = true; } } // Explicitly release the lock. void unlock() { if (locked_) { mutex_.unlock(); locked_ = false; } } // Test whether the lock is held. bool locked() const { return locked_; } // Get the underlying mutex. Mutex& mutex() { return mutex_; } private: // The underlying mutex. Mutex& mutex_; // Whether the mutex is currently locked or unlocked. bool locked_; }; } // namespace detail } // namespace asio } // namespace boost #include <boost/asio/detail/pop_options.hpp> #endif // BOOST_ASIO_DETAIL_SCOPED_LOCK_HPP