Chris@16: /*
Chris@101:  *          Copyright Andrey Semashev 2007 - 2015.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  *    (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  *          http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  */
Chris@16: /*!
Chris@16:  * \file   spin_mutex.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   01.08.2010
Chris@16:  *
Chris@16:  * \brief  This header is the Boost.Log library implementation, see the library documentation
Chris@16:  *         at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_DETAIL_SPIN_MUTEX_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_DETAIL_SPIN_MUTEX_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #ifndef BOOST_LOG_NO_THREADS
Chris@16: 
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: #include <boost/thread/exceptions.hpp>
Chris@16: 
Chris@16: #if defined(BOOST_THREAD_POSIX) // This one can be defined by users, so it should go first
Chris@16: #define BOOST_LOG_SPIN_MUTEX_USE_PTHREAD
Chris@16: #elif defined(BOOST_WINDOWS)
Chris@16: #define BOOST_LOG_SPIN_MUTEX_USE_WINAPI
Chris@16: #elif defined(BOOST_HAS_PTHREADS)
Chris@16: #define BOOST_LOG_SPIN_MUTEX_USE_PTHREAD
Chris@16: #endif
Chris@16: 
Chris@16: #if defined(BOOST_LOG_SPIN_MUTEX_USE_WINAPI)
Chris@16: 
Chris@16: #include <boost/detail/interlocked.hpp>
Chris@16: 
Chris@16: #if defined(BOOST_USE_WINDOWS_H)
Chris@16: 
Chris@16: #ifndef _WIN32_WINNT
Chris@16: #define _WIN32_WINNT 0x0500
Chris@16: #endif
Chris@16: 
Chris@16: #include <windows.h>
Chris@16: 
Chris@16: #else // defined(BOOST_USE_WINDOWS_H)
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16: extern "C" {
Chris@16: 
Chris@16: __declspec(dllimport) int __stdcall SwitchToThread();
Chris@16: 
Chris@16: } // extern "C"
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_USE_WINDOWS_H
Chris@16: 
Chris@16: #if defined(__INTEL_COMPILER) || defined(_MSC_VER)
Chris@16: #    if defined(_M_IX86)
Chris@16: #        define BOOST_LOG_PAUSE_OP __asm { pause }
Chris@16: #    elif defined(_M_AMD64)
Chris@16: extern "C" void _mm_pause(void);
Chris@16: #pragma intrinsic(_mm_pause)
Chris@16: #        define BOOST_LOG_PAUSE_OP _mm_pause()
Chris@16: #    endif
Chris@16: #    if defined(__INTEL_COMPILER)
Chris@16: #        define BOOST_LOG_COMPILER_BARRIER __memory_barrier()
Chris@16: #    else
Chris@16: extern "C" void _ReadWriteBarrier(void);
Chris@16: #pragma intrinsic(_ReadWriteBarrier)
Chris@16: #        define BOOST_LOG_COMPILER_BARRIER _ReadWriteBarrier()
Chris@16: #    endif
Chris@16: #elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
Chris@16: #    define BOOST_LOG_PAUSE_OP __asm__ __volatile__("pause;")
Chris@16: #    define BOOST_LOG_COMPILER_BARRIER __asm__ __volatile__("" : : : "memory")
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/log/detail/header.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16: //! A simple spinning mutex
Chris@16: class spin_mutex
Chris@16: {
Chris@16: private:
Chris@16:     enum state
Chris@16:     {
Chris@16:         initial_pause = 2,
Chris@16:         max_pause = 16
Chris@16:     };
Chris@16: 
Chris@16:     long m_State;
Chris@16: 
Chris@16: public:
Chris@16:     spin_mutex() : m_State(0) {}
Chris@16: 
Chris@16:     bool try_lock()
Chris@16:     {
Chris@16:         return (BOOST_INTERLOCKED_COMPARE_EXCHANGE(&m_State, 1L, 0L) == 0L);
Chris@16:     }
Chris@16: 
Chris@16:     void lock()
Chris@16:     {
Chris@16: #if defined(BOOST_LOG_PAUSE_OP)
Chris@101:         unsigned int pause_count = initial_pause;
Chris@16: #endif
Chris@16:         while (!try_lock())
Chris@16:         {
Chris@16: #if defined(BOOST_LOG_PAUSE_OP)
Chris@16:             if (pause_count < max_pause)
Chris@16:             {
Chris@101:                 for (unsigned int i = 0; i < pause_count; ++i)
Chris@16:                 {
Chris@16:                     BOOST_LOG_PAUSE_OP;
Chris@16:                 }
Chris@16:                 pause_count += pause_count;
Chris@16:             }
Chris@16:             else
Chris@16:             {
Chris@16:                 // Restart spinning after waking up this thread
Chris@16:                 pause_count = initial_pause;
Chris@16:                 SwitchToThread();
Chris@16:             }
Chris@16: #else
Chris@16:             SwitchToThread();
Chris@16: #endif
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     void unlock()
Chris@16:     {
Chris@16: #if (defined(_M_IX86) || defined(_M_AMD64)) && defined(BOOST_LOG_COMPILER_BARRIER)
Chris@16:         BOOST_LOG_COMPILER_BARRIER;
Chris@16:         m_State = 0L;
Chris@16:         BOOST_LOG_COMPILER_BARRIER;
Chris@16: #else
Chris@16:         BOOST_INTERLOCKED_EXCHANGE(&m_State, 0L);
Chris@16: #endif
Chris@16:     }
Chris@16: 
Chris@16:     //  Non-copyable
Chris@16:     BOOST_DELETED_FUNCTION(spin_mutex(spin_mutex const&))
Chris@16:     BOOST_DELETED_FUNCTION(spin_mutex& operator= (spin_mutex const&))
Chris@16: };
Chris@16: 
Chris@16: #undef BOOST_LOG_PAUSE_OP
Chris@16: #undef BOOST_LOG_COMPILER_BARRIER
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/log/detail/footer.hpp>
Chris@16: 
Chris@16: #elif defined(BOOST_LOG_SPIN_MUTEX_USE_PTHREAD)
Chris@16: 
Chris@16: #include <pthread.h>
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/log/detail/header.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16: #if defined(_POSIX_SPIN_LOCKS) && _POSIX_SPIN_LOCKS > 0
Chris@16: 
Chris@16: //! A simple spinning mutex
Chris@16: class spin_mutex
Chris@16: {
Chris@16: private:
Chris@16:     pthread_spinlock_t m_State;
Chris@16: 
Chris@16: public:
Chris@16:     spin_mutex()
Chris@16:     {
Chris@16:         const int err = pthread_spin_init(&m_State, PTHREAD_PROCESS_PRIVATE);
Chris@16:         if (err != 0)
Chris@16:             throw_exception< thread_resource_error >(err, "failed to initialize a spin mutex", "spin_mutex::spin_mutex()", __FILE__, __LINE__);
Chris@16:     }
Chris@16: 
Chris@16:     ~spin_mutex()
Chris@16:     {
Chris@16:         BOOST_VERIFY(pthread_spin_destroy(&m_State) == 0);
Chris@16:     }
Chris@16: 
Chris@16:     bool try_lock()
Chris@16:     {
Chris@16:         const int err = pthread_spin_trylock(&m_State);
Chris@16:         if (err == 0)
Chris@16:             return true;
Chris@16:         if (err != EBUSY)
Chris@16:             throw_exception< lock_error >(err, "failed to lock a spin mutex", "spin_mutex::try_lock()", __FILE__, __LINE__);
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16:     void lock()
Chris@16:     {
Chris@16:         const int err = pthread_spin_lock(&m_State);
Chris@16:         if (err != 0)
Chris@16:             throw_exception< lock_error >(err, "failed to lock a spin mutex", "spin_mutex::lock()", __FILE__, __LINE__);
Chris@16:     }
Chris@16: 
Chris@16:     void unlock()
Chris@16:     {
Chris@16:         BOOST_VERIFY(pthread_spin_unlock(&m_State) == 0);
Chris@16:     }
Chris@16: 
Chris@16:     //  Non-copyable
Chris@16:     BOOST_DELETED_FUNCTION(spin_mutex(spin_mutex const&))
Chris@16:     BOOST_DELETED_FUNCTION(spin_mutex& operator= (spin_mutex const&))
Chris@16: 
Chris@16: private:
Chris@16:     template< typename ExceptionT >
Chris@16:     static BOOST_NOINLINE BOOST_LOG_NORETURN void throw_exception(int err, const char* descr, const char* func, const char* file, int line)
Chris@16:     {
Chris@16: #if !defined(BOOST_EXCEPTION_DISABLE)
Chris@16:         boost::exception_detail::throw_exception_(ExceptionT(err, descr), func, file, line);
Chris@16: #else
Chris@16:         boost::throw_exception(ExceptionT(err, descr));
Chris@16: #endif
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: #else // defined(_POSIX_SPIN_LOCKS)
Chris@16: 
Chris@16: //! Backup implementation in case if pthreads don't support spin locks
Chris@16: class spin_mutex
Chris@16: {
Chris@16: private:
Chris@16:     pthread_mutex_t m_State;
Chris@16: 
Chris@16: public:
Chris@16:     spin_mutex()
Chris@16:     {
Chris@16:         const int err = pthread_mutex_init(&m_State, NULL);
Chris@16:         if (err != 0)
Chris@16:             throw_exception< thread_resource_error >(err, "failed to initialize a spin mutex", "spin_mutex::spin_mutex()", __FILE__, __LINE__);
Chris@16:     }
Chris@16: 
Chris@16:     ~spin_mutex()
Chris@16:     {
Chris@16:         BOOST_VERIFY(pthread_mutex_destroy(&m_State) == 0);
Chris@16:     }
Chris@16: 
Chris@16:     bool try_lock()
Chris@16:     {
Chris@16:         const int err = pthread_mutex_trylock(&m_State);
Chris@16:         if (err == 0)
Chris@16:             return true;
Chris@16:         if (err != EBUSY)
Chris@16:             throw_exception< lock_error >(err, "failed to lock a spin mutex", "spin_mutex::try_lock()", __FILE__, __LINE__);
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16:     void lock()
Chris@16:     {
Chris@16:         const int err = pthread_mutex_lock(&m_State);
Chris@16:         if (err != 0)
Chris@16:             throw_exception< lock_error >(err, "failed to lock a spin mutex", "spin_mutex::lock()", __FILE__, __LINE__);
Chris@16:     }
Chris@16: 
Chris@16:     void unlock()
Chris@16:     {
Chris@16:         BOOST_VERIFY(pthread_mutex_unlock(&m_State) == 0);
Chris@16:     }
Chris@16: 
Chris@16:     //  Non-copyable
Chris@16:     BOOST_DELETED_FUNCTION(spin_mutex(spin_mutex const&))
Chris@16:     BOOST_DELETED_FUNCTION(spin_mutex& operator= (spin_mutex const&))
Chris@16: 
Chris@16: private:
Chris@16:     template< typename ExceptionT >
Chris@16:     static BOOST_NOINLINE BOOST_LOG_NORETURN void throw_exception(int err, const char* descr, const char* func, const char* file, int line)
Chris@16:     {
Chris@16: #if !defined(BOOST_EXCEPTION_DISABLE)
Chris@16:         boost::exception_detail::throw_exception_(ExceptionT(err, descr), func, file, line);
Chris@16: #else
Chris@16:         boost::throw_exception(ExceptionT(err, descr));
Chris@16: #endif
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: #endif // defined(_POSIX_SPIN_LOCKS)
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/log/detail/footer.hpp>
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: #endif // BOOST_LOG_NO_THREADS
Chris@16: 
Chris@16: #endif // BOOST_LOG_DETAIL_SPIN_MUTEX_HPP_INCLUDED_