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- // 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/header_deprecated.hpp>
- BOOST_HEADER_DEPRECATED( "the facilities in <boost/timer/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
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