Boost C++ Libraries

boost/interprocess/sync/detail/condition_any_algorithm.hpp

//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2012-2012. 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_CONDITION_ANY_ALGORITHM_HPP
#define BOOST_INTERPROCESS_DETAIL_CONDITION_ANY_ALGORITHM_HPP

#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/detail/workaround.hpp>
#include <boost/interprocess/sync/scoped_lock.hpp>
#include <boost/interprocess/sync/detail/locks.hpp>
#include <limits>

namespace boost {
namespace interprocess {
namespace ipcdetail {

////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
//
// Condition variable 'any' (able to use any type of external mutex)
//
// The code is based on Howard E. Hinnant's ISO C++ N2406 paper.
// Many thanks to Howard for his support and comments.
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////

// Required interface for ConditionAnyMembers
// class ConditionAnyMembers
// {
//    typedef implementation_defined mutex_type;
//    typedef implementation_defined condvar_type;
//
//    condvar     &get_condvar()
//    mutex_type  &get_mutex()
// };
//
// Must be initialized as following
//
//    get_condvar()  [no threads blocked]
//    get_mutex()    [unlocked]

template<class ConditionAnyMembers>
class condition_any_algorithm
{
   private:
   condition_any_algorithm();
   ~condition_any_algorithm();
   condition_any_algorithm(const condition_any_algorithm &);
   condition_any_algorithm &operator=(const condition_any_algorithm &);

   typedef typename ConditionAnyMembers::mutex_type      mutex_type;
   typedef typename ConditionAnyMembers::condvar_type    condvar_type;

   template <class Lock>
   static void do_wait(ConditionAnyMembers &data, Lock& lock);

   template <class Lock>
   static bool do_timed_wait(ConditionAnyMembers &data, Lock& lock, const boost::posix_time::ptime &abs_time);

   public:
   template<class Lock>
   static bool wait  ( ConditionAnyMembers &data, Lock &mut
                     , bool timeout_enabled, const boost::posix_time::ptime &abs_time);
   static void signal( ConditionAnyMembers &data, bool broadcast);
};

template<class ConditionAnyMembers>
void condition_any_algorithm<ConditionAnyMembers>::signal(ConditionAnyMembers &data, bool broadcast)
{
   scoped_lock<mutex_type> internal_lock(data.get_mutex());
   if(broadcast){
      data.get_condvar().notify_all();
   }
   else{
      data.get_condvar().notify_one();
   }
}

template<class ConditionAnyMembers>
template<class Lock>
bool condition_any_algorithm<ConditionAnyMembers>::wait
   ( ConditionAnyMembers &data
   , Lock &lock
   , bool tout_enabled
   , const boost::posix_time::ptime &abs_time)
{
   if(tout_enabled){
      return condition_any_algorithm::do_timed_wait(data, lock, abs_time);
   }
   else{
      condition_any_algorithm::do_wait(data, lock);
      return true;
   }
}

template<class ConditionAnyMembers>
template <class Lock>
void condition_any_algorithm<ConditionAnyMembers>::do_wait
   (ConditionAnyMembers &data, Lock& lock)
{
   //lock internal before unlocking external to avoid race with a notifier
   scoped_lock<mutex_type> internal_lock(data.get_mutex());
   {
      lock_inverter<Lock> inverted_lock(lock);
      scoped_lock<lock_inverter<Lock> >   external_unlock(inverted_lock);
      {  //unlock internal first to avoid deadlock with near simultaneous waits
         scoped_lock<mutex_type>     internal_unlock;
         internal_lock.swap(internal_unlock);
         data.get_condvar().wait(internal_unlock);
      }
   }
}

template<class ConditionAnyMembers>
template <class Lock>
bool condition_any_algorithm<ConditionAnyMembers>::do_timed_wait
   (ConditionAnyMembers &data, Lock& lock, const boost::posix_time::ptime &abs_time)
{
   //lock internal before unlocking external to avoid race with a notifier
   scoped_lock<mutex_type> internal_lock(data.get_mutex());
   {
      //Unlock external lock and program for relock
      lock_inverter<Lock> inverted_lock(lock);
      scoped_lock<lock_inverter<Lock> >   external_unlock(inverted_lock);
      {  //unlock internal first to avoid deadlock with near simultaneous waits
         scoped_lock<mutex_type> internal_unlock;
         internal_lock.swap(internal_unlock);
         return data.get_condvar().timed_wait(internal_unlock, abs_time);
      }
   }
}


template<class ConditionAnyMembers>
class condition_any_wrapper
{
   //Non-copyable
   condition_any_wrapper(const condition_any_wrapper &);
   condition_any_wrapper &operator=(const condition_any_wrapper &);

   ConditionAnyMembers m_data;
   typedef ipcdetail::condition_any_algorithm<ConditionAnyMembers> algo_type;

   public:

   condition_any_wrapper(){}

   ~condition_any_wrapper(){}

   ConditionAnyMembers & get_members()
   {  return m_data; }

   const ConditionAnyMembers & get_members() const
   {  return m_data; }

   void notify_one()
   {  algo_type::signal(m_data, false);  }

   void notify_all()
   {  algo_type::signal(m_data, true);  }

   template <typename L>
   void wait(L& lock)
   {
      if (!lock)
         throw lock_exception();
      algo_type::wait(m_data, lock, false, boost::posix_time::ptime());
   }

   template <typename L, typename Pr>
   void wait(L& lock, Pr pred)
   {
      if (!lock)
         throw lock_exception();

      while (!pred())
         algo_type::wait(m_data, lock, false, boost::posix_time::ptime());
   }

   template <typename L>
   bool timed_wait(L& lock, const boost::posix_time::ptime &abs_time)
   {
      if(abs_time == boost::posix_time::pos_infin){
         this->wait(lock);
         return true;
      }
      if (!lock)
         throw lock_exception();
      return algo_type::wait(m_data, lock, true, abs_time);
   }

   template <typename L, typename Pr>
   bool timed_wait(L& lock, const boost::posix_time::ptime &abs_time, Pr pred)
   {
      if(abs_time == boost::posix_time::pos_infin){
         this->wait(lock, pred);
         return true;
      }
      if (!lock)
            throw lock_exception();
      while (!pred()){
         if (!algo_type::wait(m_data, lock, true, abs_time))
            return pred();
      }
      return true;
   }
};

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

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

#endif   //BOOST_INTERPROCESS_DETAIL_CONDITION_ANY_ALGORITHM_HPP