Mercurial > hg > vamp-build-and-test
comparison DEPENDENCIES/generic/include/boost/timer.hpp @ 16:2665513ce2d3
Add boost headers
author | Chris Cannam |
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date | Tue, 05 Aug 2014 11:11:38 +0100 |
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1 // boost timer.hpp header file ---------------------------------------------// | |
2 | |
3 // Copyright Beman Dawes 1994-99. Distributed under the Boost | |
4 // Software License, Version 1.0. (See accompanying file | |
5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
6 | |
7 // See http://www.boost.org/libs/timer for documentation. | |
8 | |
9 // Revision History | |
10 // 01 Apr 01 Modified to use new <boost/limits.hpp> header. (JMaddock) | |
11 // 12 Jan 01 Change to inline implementation to allow use without library | |
12 // builds. See docs for more rationale. (Beman Dawes) | |
13 // 25 Sep 99 elapsed_max() and elapsed_min() added (John Maddock) | |
14 // 16 Jul 99 Second beta | |
15 // 6 Jul 99 Initial boost version | |
16 | |
17 #ifndef BOOST_TIMER_HPP | |
18 #define BOOST_TIMER_HPP | |
19 | |
20 #include <boost/config.hpp> | |
21 #include <ctime> | |
22 #include <boost/limits.hpp> | |
23 | |
24 # ifdef BOOST_NO_STDC_NAMESPACE | |
25 namespace std { using ::clock_t; using ::clock; } | |
26 # endif | |
27 | |
28 | |
29 namespace boost { | |
30 | |
31 // timer -------------------------------------------------------------------// | |
32 | |
33 // A timer object measures elapsed time. | |
34 | |
35 // It is recommended that implementations measure wall clock rather than CPU | |
36 // time since the intended use is performance measurement on systems where | |
37 // total elapsed time is more important than just process or CPU time. | |
38 | |
39 // Warnings: The maximum measurable elapsed time may well be only 596.5+ hours | |
40 // due to implementation limitations. The accuracy of timings depends on the | |
41 // accuracy of timing information provided by the underlying platform, and | |
42 // this varies a great deal from platform to platform. | |
43 | |
44 class timer | |
45 { | |
46 public: | |
47 timer() { _start_time = std::clock(); } // postcondition: elapsed()==0 | |
48 // timer( const timer& src ); // post: elapsed()==src.elapsed() | |
49 // ~timer(){} | |
50 // timer& operator=( const timer& src ); // post: elapsed()==src.elapsed() | |
51 void restart() { _start_time = std::clock(); } // post: elapsed()==0 | |
52 double elapsed() const // return elapsed time in seconds | |
53 { return double(std::clock() - _start_time) / CLOCKS_PER_SEC; } | |
54 | |
55 double elapsed_max() const // return estimated maximum value for elapsed() | |
56 // Portability warning: elapsed_max() may return too high a value on systems | |
57 // where std::clock_t overflows or resets at surprising values. | |
58 { | |
59 return (double((std::numeric_limits<std::clock_t>::max)()) | |
60 - double(_start_time)) / double(CLOCKS_PER_SEC); | |
61 } | |
62 | |
63 double elapsed_min() const // return minimum value for elapsed() | |
64 { return double(1)/double(CLOCKS_PER_SEC); } | |
65 | |
66 private: | |
67 std::clock_t _start_time; | |
68 }; // timer | |
69 | |
70 } // namespace boost | |
71 | |
72 #endif // BOOST_TIMER_HPP |