Boost C++ Libraries

boost/interprocess/sync/posix/mutex.hpp

//////////////////////////////////////////////////////////////////////////////
//
// (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.
//
//////////////////////////////////////////////////////////////////////////////
//
// Parts of the pthread code come from Boost Threads code:
//
//////////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001-2003
// William E. Kempf
//
// Permission to use, copy, modify, distribute and sell this software
// and its documentation for any purpose is hereby granted without fee,
// provided that the above copyright notice appear in all copies and
// that both that copyright notice and this permission notice appear
// in supporting documentation.  William E. Kempf makes no representations
// about the suitability of this software for any purpose.
// It is provided "as is" without express or implied warranty.
//////////////////////////////////////////////////////////////////////////////

#ifndef BOOST_INTERPROCESS_DETAIL_POSIX_MUTEX_HPP
#define BOOST_INTERPROCESS_DETAIL_POSIX_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 <pthread.h>
#include <errno.h>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/sync/posix/timepoint_to_timespec.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/sync/posix/pthread_helpers.hpp>
#include <boost/interprocess/timed_utils.hpp>


#ifndef BOOST_INTERPROCESS_POSIX_TIMEOUTS
#  include <boost/interprocess/detail/os_thread_functions.hpp>
#  include <boost/interprocess/sync/detail/common_algorithms.hpp>
#endif
#include <boost/assert.hpp>

namespace boost {
namespace interprocess {
namespace ipcdetail {

class posix_condition;

class posix_mutex
{
   posix_mutex(const posix_mutex &);
   posix_mutex &operator=(const posix_mutex &);
   public:

   posix_mutex();
   ~posix_mutex();

   void lock();
   bool try_lock();
   template<class TimePoint> bool timed_lock(const TimePoint &abs_time);

   template<class TimePoint> bool try_lock_until(const TimePoint &abs_time)
   {  return this->timed_lock(abs_time);  }

   template<class Duration>  bool try_lock_for(const Duration &dur)
   {  return this->timed_lock(duration_to_ustime(dur)); }

   void unlock();

   friend class posix_condition;

   private:
   pthread_mutex_t   m_mut;
};

inline posix_mutex::posix_mutex()
{
   mutexattr_wrapper mut_attr;
   mutex_initializer mut(m_mut, mut_attr);
   mut.release();
}

inline posix_mutex::~posix_mutex()
{
   int res = pthread_mutex_destroy(&m_mut);
   BOOST_ASSERT(res  == 0);(void)res;
}

inline void posix_mutex::lock()
{
   int res = pthread_mutex_lock(&m_mut);
   #ifdef BOOST_INTERPROCESS_POSIX_ROBUST_MUTEXES
   if (res == EOWNERDEAD)
   {
      //We can't inform the application and data might
      //corrupted, so be safe and mark the mutex as not recoverable
      //so applications can act accordingly.
      pthread_mutex_unlock(&m_mut);
      throw lock_exception(not_recoverable);
   }
   else if (res == ENOTRECOVERABLE)
      throw lock_exception(not_recoverable);
   #endif
   if (res != 0)
      throw lock_exception();
}

inline bool posix_mutex::try_lock()
{
   int res = pthread_mutex_trylock(&m_mut);
   #ifdef BOOST_INTERPROCESS_POSIX_ROBUST_MUTEXES
   if (res == EOWNERDEAD)
   {
      //We can't inform the application and data might
      //corrupted, so be safe and mark the mutex as not recoverable
      //so applications can act accordingly.
      pthread_mutex_unlock(&m_mut);
      throw lock_exception(not_recoverable);
   }
   else if (res == ENOTRECOVERABLE)
      throw lock_exception(not_recoverable);
   #endif
   if (!(res == 0 || res == EBUSY))
      throw lock_exception();
   return res == 0;
}

template<class TimePoint>
inline bool posix_mutex::timed_lock(const TimePoint &abs_time)
{
   #ifdef BOOST_INTERPROCESS_POSIX_TIMEOUTS
   //Posix does not support infinity absolute time so handle it here
   if(ipcdetail::is_pos_infinity(abs_time)){
      this->lock();
      return true;
   }
   timespec ts = timepoint_to_timespec(abs_time);
   int res = pthread_mutex_timedlock(&m_mut, &ts);
   #ifdef BOOST_INTERPROCESS_POSIX_ROBUST_MUTEXES
   if (res == EOWNERDEAD)
   {
      //We can't inform the application and data might
      //corrupted, so be safe and mark the mutex as not recoverable
      //so applications can act accordingly.
      pthread_mutex_unlock(&m_mut);
      throw lock_exception(not_recoverable);
   }
   else if (res == ENOTRECOVERABLE)
      throw lock_exception(not_recoverable);
   #endif
   if (res != 0 && res != ETIMEDOUT)
      throw lock_exception();
   return res == 0;

   #else //BOOST_INTERPROCESS_POSIX_TIMEOUTS

   return ipcdetail::try_based_timed_lock(*this, abs_time);

   #endif   //BOOST_INTERPROCESS_POSIX_TIMEOUTS
}

inline void posix_mutex::unlock()
{
   int res = pthread_mutex_unlock(&m_mut);
   (void)res;
   BOOST_ASSERT(res == 0);
}

}  //namespace ipcdetail {
}  //namespace interprocess {
}  //namespace boost {

#include <boost/interprocess/detail/config_end.hpp>

#endif   //#ifndef BOOST_INTERPROCESS_DETAIL_POSIX_MUTEX_HPP