74 lines
2.7 KiB
C++
74 lines
2.7 KiB
C++
// boost timer.hpp header file ---------------------------------------------//
|
|
|
|
// Copyright Beman Dawes 1994-99. 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/timer for documentation.
|
|
|
|
// Revision History
|
|
// 01 Apr 01 Modified to use new <boost/limits.hpp> header. (JMaddock)
|
|
// 12 Jan 01 Change to inline implementation to allow use without library
|
|
// builds. See docs for more rationale. (Beman Dawes)
|
|
// 25 Sep 99 elapsed_max() and elapsed_min() added (John Maddock)
|
|
// 16 Jul 99 Second beta
|
|
// 6 Jul 99 Initial boost version
|
|
|
|
#ifndef BOOST_TIMER_HPP
|
|
#define BOOST_TIMER_HPP
|
|
|
|
//#include <boost/config.hpp>
|
|
#include <ctime>
|
|
#include <limits>
|
|
//#include <boost/limits.hpp>
|
|
|
|
# ifdef BOOST_NO_STDC_NAMESPACE
|
|
namespace std { using ::clock_t; using ::clock; }
|
|
# endif
|
|
|
|
|
|
namespace boost {
|
|
|
|
// timer -------------------------------------------------------------------//
|
|
|
|
// A timer object measures elapsed time.
|
|
|
|
// It is recommended that implementations measure wall clock rather than CPU
|
|
// time since the intended use is performance measurement on systems where
|
|
// total elapsed time is more important than just process or CPU time.
|
|
|
|
// Warnings: The maximum measurable elapsed time may well be only 596.5+ hours
|
|
// due to implementation limitations. The accuracy of timings depends on the
|
|
// accuracy of timing information provided by the underlying platform, and
|
|
// this varies a great deal from platform to platform.
|
|
|
|
class timer
|
|
{
|
|
public:
|
|
timer() { _start_time = std::clock(); } // postcondition: elapsed()==0
|
|
// timer( const timer& src ); // post: elapsed()==src.elapsed()
|
|
// ~timer(){}
|
|
// timer& operator=( const timer& src ); // post: elapsed()==src.elapsed()
|
|
void restart() { _start_time = std::clock(); } // post: elapsed()==0
|
|
double elapsed() const // return elapsed time in seconds
|
|
{ return double(std::clock() - _start_time) / CLOCKS_PER_SEC; }
|
|
|
|
double elapsed_max() const // return estimated maximum value for elapsed()
|
|
// Portability warning: elapsed_max() may return too high a value on systems
|
|
// where std::clock_t overflows or resets at surprising values.
|
|
{
|
|
return (double((std::numeric_limits<std::clock_t>::max)())
|
|
- double(_start_time)) / double(CLOCKS_PER_SEC);
|
|
}
|
|
|
|
double elapsed_min() const // return minimum value for elapsed()
|
|
{ return double(1)/double(CLOCKS_PER_SEC); }
|
|
|
|
private:
|
|
std::clock_t _start_time;
|
|
}; // timer
|
|
|
|
} // namespace boost
|
|
|
|
#endif // BOOST_TIMER_HPP
|