Condition.hpp

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/***************************************************************************
  tag: The SourceWorks  Tue Sep 7 00:55:18 CEST 2010  Condition.hpp

                        Condition.hpp -  description
                           -------------------
    begin                : Tue September 07 2010
    copyright            : (C) 2010 The SourceWorks
    email                : peter@thesourceworks.com

 ***************************************************************************
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU General Public                   *
 *   License as published by the Free Software Foundation;                 *
 *   version 2 of the License.                                             *
 *                                                                         *
 *   As a special exception, you may use this file as part of a free       *
 *   software library without restriction.  Specifically, if other files   *
 *   instantiate templates or use macros or inline functions from this     *
 *   file, or you compile this file and link it with other files to        *
 *   produce an executable, this file does not by itself cause the         *
 *   resulting executable to be covered by the GNU General Public          *
 *   License.  This exception does not however invalidate any other        *
 *   reasons why the executable file might be covered by the GNU General   *
 *   Public License.                                                       *
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 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
 *   Lesser General Public License for more details.                       *
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 *   Foundation, Inc., 59 Temple Place,                                    *
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 ***************************************************************************/


#ifndef OS_CONDITION_HPP
#define OS_CONDITION_HPP

#include "fosi.h"
#include "../rtt-config.h"
#include "Time.hpp"
#include "Mutex.hpp"
#ifdef ORO_OS_USE_BOOST_THREAD
// BOOST_DATE_TIME_POSIX_TIME_STD_CONFIG is defined in rtt-config.h
#include <boost/thread/condition.hpp>
#include <boost/date_time/posix_time/posix_time_types.hpp>
#endif

namespace RTT
{ namespace os {

    class RTT_API Condition
    {
#ifndef ORO_OS_USE_BOOST_THREAD
    protected:
        rt_cond_t c;
    public:
        Condition()
        {
            rtos_cond_init( &c);
        }

        ~Condition()
        {
            rtos_cond_destroy( &c );
        }

        bool wait (Mutex& m)
        {
            return rtos_cond_wait( &c, &m.m ) == 0 ? true : false;
        }

        template<class Predicate>
        bool wait (Mutex& m, Predicate& p)
        {
            while( !p() )
                if ( rtos_cond_wait( &c, &m.m ) != 0) return false;
            return true;
        }
        void broadcast()
        {
            rtos_cond_broadcast( &c );
        }

        bool wait_until(Mutex& m, nsecs abs_time)
        {
            if ( rtos_cond_timedwait( &c, &m.m, abs_time ) == 0 )
                return true;
            return false;
        }
#else
    protected:
        boost::condition_variable_any c;
    public:
        Condition()
        {
        }

        ~Condition()
        {
        }

        bool wait (Mutex& m)
        {
            c.wait(m.m);
            return true;
        }

        template<class Predicate>
        bool wait (Mutex& m, Predicate& p)
        {
            c.wait(m.m, p);
            return true;
        }
        void broadcast()
        {
            c.notify_all();
        }

        bool wait_until(Mutex& m, nsecs abs_time)
        {
            // abs_time is since epoch, so set p_time to epoch, then add our abs_time.
            boost::posix_time::ptime p_time = boost::posix_time::from_time_t(0);

            // If the line below fails to compile, #define BOOST_DATE_TIME_POSIX_TIME_STD_CONFIG globally
            // or #include <rtt/rtt-config.h> before any of your include headers.
            boost::posix_time::nanosec abs_p_time = boost::posix_time::nanoseconds(abs_time);

            // wakeup time = epoch date + time since epoch
            p_time = p_time + abs_p_time;
            return c.timed_wait(m, p_time, &Condition::retfalse );
        }
    private:
        static bool retfalse() { return false; }

#endif

    };
}}

#endif