| // 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 <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 |