| ////////////////////////////////////////////////////////////////////////////// |
| // |
| // (C) Copyright Ion Gaztanaga 2005-2012. 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) |
| // |
| // See http://www.boost.org/libs/interprocess for documentation. |
| // |
| ////////////////////////////////////////////////////////////////////////////// |
| |
| #ifndef BOOST_INTERPROCESS_DETAIL_SPIN_MUTEX_HPP |
| #define BOOST_INTERPROCESS_DETAIL_SPIN_MUTEX_HPP |
| |
| #ifndef BOOST_CONFIG_HPP |
| # include <boost/config.hpp> |
| #endif |
| # |
| #if defined(BOOST_HAS_PRAGMA_ONCE) |
| # pragma once |
| #endif |
| |
| #include <boost/interprocess/detail/config_begin.hpp> |
| #include <boost/interprocess/detail/workaround.hpp> |
| #include <boost/interprocess/detail/posix_time_types_wrk.hpp> |
| #include <boost/assert.hpp> |
| #include <boost/interprocess/detail/atomic.hpp> |
| #include <boost/cstdint.hpp> |
| #include <boost/interprocess/detail/os_thread_functions.hpp> |
| #include <boost/interprocess/sync/detail/common_algorithms.hpp> |
| |
| namespace boost { |
| namespace interprocess { |
| namespace ipcdetail { |
| |
| class spin_mutex |
| { |
| spin_mutex(const spin_mutex &); |
| spin_mutex &operator=(const spin_mutex &); |
| public: |
| |
| spin_mutex(); |
| ~spin_mutex(); |
| |
| void lock(); |
| bool try_lock(); |
| bool timed_lock(const boost::posix_time::ptime &abs_time); |
| void unlock(); |
| void take_ownership(){}; |
| private: |
| volatile boost::uint32_t m_s; |
| }; |
| |
| inline spin_mutex::spin_mutex() |
| : m_s(0) |
| { |
| //Note that this class is initialized to zero. |
| //So zeroed memory can be interpreted as an |
| //initialized mutex |
| } |
| |
| inline spin_mutex::~spin_mutex() |
| { |
| //Trivial destructor |
| } |
| |
| inline void spin_mutex::lock(void) |
| { return ipcdetail::try_based_lock(*this); } |
| |
| inline bool spin_mutex::try_lock(void) |
| { |
| boost::uint32_t prev_s = ipcdetail::atomic_cas32(const_cast<boost::uint32_t*>(&m_s), 1, 0); |
| return m_s == 1 && prev_s == 0; |
| } |
| |
| inline bool spin_mutex::timed_lock(const boost::posix_time::ptime &abs_time) |
| { return ipcdetail::try_based_timed_lock(*this, abs_time); } |
| |
| inline void spin_mutex::unlock(void) |
| { ipcdetail::atomic_cas32(const_cast<boost::uint32_t*>(&m_s), 0, 1); } |
| |
| } //namespace ipcdetail { |
| } //namespace interprocess { |
| } //namespace boost { |
| |
| #include <boost/interprocess/detail/config_end.hpp> |
| |
| #endif //BOOST_INTERPROCESS_DETAIL_SPIN_MUTEX_HPP |