vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/mpi/timer.hpp

92 lines
2.0 KiB
C++

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