#ifndef BOOST_THREAD_CONDITION_VARIABLE_STEADY_PTHREAD_HPP
#define BOOST_THREAD_CONDITION_VARIABLE_STEADY_PTHREAD_HPP

// 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)
// (C) Copyright 2007-10 Anthony Williams
// (C) Copyright 2011-2012 Vicente J. Botet Escriba
// Steady clock modifications by David Bacher

#include <pthread.h>
#include <boost/thread/pthread/condition_variable.hpp>

namespace boost
{

    class condition_variable_steady
    {
    private:
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        pthread_mutex_t internal_mutex;
#endif
        pthread_cond_t cond;

    public:
    //private: // used by boost::thread::try_join_until

        inline bool do_wait_until(
            unique_lock<mutex>& lock,
            struct timespec const &timeout);

        bool do_wait_for(
            unique_lock<mutex>& lock,
            struct timespec const &timeout)
        {
          return do_wait_until(lock, boost::detail::timespec_plus(timeout, boost::detail::timespec_now()));
        }

    public:
      BOOST_THREAD_NO_COPYABLE(condition_variable_steady)
        condition_variable_steady()
        {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
            int const res=pthread_mutex_init(&internal_mutex,NULL);
            if(res)
            {
                boost::throw_exception(thread_resource_error(res, "boost::condition_variable_steady::condition_variable_steady() constructor failed in pthread_mutex_init"));
            }
#endif

            pthread_condattr_t attr;
            int const res2 = pthread_condattr_init(&attr);
            if(res2)
            {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
                BOOST_VERIFY(!pthread_mutex_destroy(&internal_mutex));
#endif
                boost::throw_exception(thread_resource_error(res2, "boost::condition_variable_steady::condition_variable_steady() constructor failed in pthread_condattr_init"));
            }
            pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
            int const res3=pthread_cond_init(&cond,&attr);
            pthread_condattr_destroy(&attr);
            if(res3)
            {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
                BOOST_VERIFY(!pthread_mutex_destroy(&internal_mutex));
#endif
                boost::throw_exception(thread_resource_error(res3, "boost::condition_variable_steady::condition_variable_steady() constructor failed in pthread_cond_init"));
            }
            
        }
        ~condition_variable_steady()
        {
            int ret;
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
            do {
              ret = pthread_mutex_destroy(&internal_mutex);
            } while (ret == EINTR);
            BOOST_ASSERT(!ret);
#endif
            do {
              ret = pthread_cond_destroy(&cond);
            } while (ret == EINTR);
            BOOST_ASSERT(!ret);
        }

        void wait(unique_lock<mutex>& m);

        template<typename predicate_type>
        void wait(unique_lock<mutex>& m,predicate_type pred)
        {
            while(!pred()) wait(m);
        }

#ifdef BOOST_THREAD_USES_CHRONO

        template <class Duration>
        cv_status
        wait_until(
                unique_lock<mutex>& lock,
                const chrono::time_point<chrono::steady_clock, Duration>& t)
        {
          using namespace chrono;
          typedef time_point<steady_clock, nanoseconds> nano_sys_tmpt;
          wait_until(lock,
                        nano_sys_tmpt(ceil<nanoseconds>(t.time_since_epoch())));
          return steady_clock::now() < t ? cv_status::no_timeout :
                                             cv_status::timeout;
        }

        template <class Clock, class Duration>
        cv_status
        wait_until(
                unique_lock<mutex>& lock,
                const chrono::time_point<Clock, Duration>& t)
        {
          using namespace chrono;
          steady_clock::time_point     s_now = steady_clock::now();
          typename Clock::time_point  c_now = Clock::now();
          wait_until(lock, s_now + ceil<nanoseconds>(t - c_now));
          return Clock::now() < t ? cv_status::no_timeout : cv_status::timeout;
        }

        template <class Clock, class Duration, class Predicate>
        bool
        wait_until(
                unique_lock<mutex>& lock,
                const chrono::time_point<Clock, Duration>& t,
                Predicate pred)
        {
            while (!pred())
            {
                if (wait_until(lock, t) == cv_status::timeout)
                    return pred();
            }
            return true;
        }


        template <class Rep, class Period>
        cv_status
        wait_for(
                unique_lock<mutex>& lock,
                const chrono::duration<Rep, Period>& d)
        {
          using namespace chrono;
          steady_clock::time_point c_now = steady_clock::now();
          wait_until(lock, c_now + ceil<nanoseconds>(d));
          return steady_clock::now() - c_now < d ? cv_status::no_timeout :
                                                   cv_status::timeout;

        }


        template <class Rep, class Period, class Predicate>
        bool
        wait_for(
                unique_lock<mutex>& lock,
                const chrono::duration<Rep, Period>& d,
                Predicate pred)
        {
          return wait_until(lock, chrono::steady_clock::now() + d, boost::move(pred));
        }
#endif

#define BOOST_THREAD_DEFINES_CONDITION_VARIABLE_NATIVE_HANDLE
        typedef pthread_cond_t* native_handle_type;
        native_handle_type native_handle()
        {
            return &cond;
        }

        void notify_one() BOOST_NOEXCEPT;
        void notify_all() BOOST_NOEXCEPT;

#ifdef BOOST_THREAD_USES_CHRONO
        inline cv_status wait_until(
            unique_lock<mutex>& lk,
            chrono::time_point<chrono::steady_clock, chrono::nanoseconds> tp)
        {
            using namespace chrono;
            nanoseconds d = tp.time_since_epoch();
            timespec ts = boost::detail::to_timespec(d);
            if (do_wait_until(lk, ts)) return cv_status::no_timeout;
            else return cv_status::timeout;
        }
#endif
    };

    BOOST_THREAD_DECL void notify_all_at_thread_exit(condition_variable_steady& cond, unique_lock<mutex> lk);

   
    inline void condition_variable_steady::wait(unique_lock<mutex>& m)
    {
#if defined BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED
        if(! m.owns_lock())
        {
            boost::throw_exception(condition_error(-1, "boost::condition_variable_steady::wait() failed precondition mutex not owned"));
        }
#endif
        int res=0;
        {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
            thread_cv_detail::lock_on_exit<unique_lock<mutex> > guard;
            detail::interruption_checker check_for_interruption(&internal_mutex,&cond);
            guard.activate(m);
            do {
              res = pthread_cond_wait(&cond,&internal_mutex);
            } while (res == EINTR);
#else
            //boost::pthread::pthread_mutex_scoped_lock check_for_interruption(&internal_mutex);
            pthread_mutex_t* the_mutex = m.mutex()->native_handle();
            do {
              res = pthread_cond_wait(&cond,the_mutex);
            } while (res == EINTR);
#endif
        }
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        this_thread::interruption_point();
#endif
        if(res)
        {
            boost::throw_exception(condition_error(res, "boost::condition_variable_steady::wait failed in pthread_cond_wait"));
        }
    }

    inline bool condition_variable_steady::do_wait_until(
                unique_lock<mutex>& m,
                struct timespec const &timeout)
    {
#if defined BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED
        if (!m.owns_lock())
        {
            boost::throw_exception(condition_error(EPERM, "boost::condition_variable_steady::do_wait_until() failed precondition mutex not owned"));
        }
#endif
        thread_cv_detail::lock_on_exit<unique_lock<mutex> > guard;
        int cond_res;
        {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
            detail::interruption_checker check_for_interruption(&internal_mutex,&cond);
            guard.activate(m);
            cond_res=pthread_cond_timedwait(&cond,&internal_mutex,&timeout);
#else
            //boost::pthread::pthread_mutex_scoped_lock check_for_interruption(&internal_mutex);
            pthread_mutex_t* the_mutex = m.mutex()->native_handle();
            cond_res=pthread_cond_timedwait(&cond,the_mutex,&timeout);
#endif
        }
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        this_thread::interruption_point();
#endif
        if(cond_res==ETIMEDOUT)
        {
            return false;
        }
        if(cond_res)
        {
            boost::throw_exception(condition_error(cond_res, "boost::condition_variable_steady::do_wait_until failed in pthread_cond_timedwait"));
        }
        return true;
    }

    inline void condition_variable_steady::notify_one() BOOST_NOEXCEPT
    {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        boost::pthread::pthread_mutex_scoped_lock internal_lock(&internal_mutex);
#endif
        BOOST_VERIFY(!pthread_cond_signal(&cond));
    }

    inline void condition_variable_steady::notify_all() BOOST_NOEXCEPT
    {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        boost::pthread::pthread_mutex_scoped_lock internal_lock(&internal_mutex);
#endif
        BOOST_VERIFY(!pthread_cond_broadcast(&cond));
    }

}

#endif