Chris@16: // Copyright (C) 2006 Douglas Gregor <doug.gregor -at- gmail.com>
Chris@16: 
Chris@16: // Use, modification and distribution is subject to the Boost Software
Chris@16: // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: /** @file timer.hpp
Chris@16:  *
Chris@16:  *  This header provides the @c timer class, which provides access to
Chris@16:  *  the MPI timers.
Chris@16:  */
Chris@16: #ifndef BOOST_MPI_TIMER_HPP
Chris@16: #define BOOST_MPI_TIMER_HPP
Chris@16: 
Chris@16: #include <boost/mpi/config.hpp>
Chris@16: #include <boost/limits.hpp>
Chris@16: 
Chris@16: namespace boost { namespace mpi {
Chris@16: 
Chris@16: /** @brief A simple timer that provides access to the MPI timing
Chris@16:  * facilities.
Chris@16:  *
Chris@16:  *  The @c timer class is a simple wrapper around the MPI timing
Chris@16:  *  facilities that mimics the interface of the Boost Timer library.
Chris@16:  */
Chris@16: class BOOST_MPI_DECL timer {
Chris@16: public:
Chris@16:   /** Initializes the timer
Chris@16:    *
Chris@16:    * @post @c elapsed() == 0
Chris@16:    */
Chris@16:   timer();
Chris@16: 
Chris@16:   /** Restart the timer.
Chris@16:    *
Chris@16:    * @post @c elapsed() == 0
Chris@16:    */
Chris@16:   void restart();
Chris@16: 
Chris@16:   /** Return the amount of time that has elapsed since the last
Chris@16:    *  construction or reset, in seconds.
Chris@16:    */
Chris@16:   double elapsed() const;
Chris@16: 
Chris@16:   /** Return an estimate of the maximum possible value of
Chris@16:    *  elapsed(). Note that this routine may return too high a value on
Chris@16:    *  some systems. 
Chris@16:    */
Chris@16:   double elapsed_max() const;  
Chris@16: 
Chris@16:   /** Returns the minimum non-zero value that @c elapsed() may
Chris@16:    *  return. This is the resolution of the timer.
Chris@16:    */
Chris@16:   double elapsed_min() const;
Chris@16: 
Chris@16:   /** Determines whether the elapsed time values are global times or
Chris@16:       local processor times. */
Chris@16:   static bool time_is_global();
Chris@16: 
Chris@16: private:
Chris@16:   double start_time;
Chris@16: }; // timer
Chris@16: 
Chris@16: inline timer::timer() 
Chris@16: { 
Chris@16:   restart(); 
Chris@16: }
Chris@16: 
Chris@16: inline void timer::restart()
Chris@16: {
Chris@16:   start_time = MPI_Wtime();
Chris@16: }
Chris@16: 
Chris@16: inline double timer::elapsed() const
Chris@16: {
Chris@16:   return MPI_Wtime() - start_time;
Chris@16: }
Chris@16: 
Chris@16: inline double timer::elapsed_max() const
Chris@16: {
Chris@16:   return (std::numeric_limits<double>::max)();
Chris@16: }
Chris@16: 
Chris@16: inline double timer::elapsed_min() const
Chris@16: {
Chris@16:   return MPI_Wtick();
Chris@16: }
Chris@16: 
Chris@16: } } // end namespace boost::mpi
Chris@16: 
Chris@16: #endif // BOOST_MPI_TIMER_HPP