ceph/src/boost/libs/chrono/stopwatches/include/boost/chrono/stopwatches/strict_stopwatch.hpp

   1 //  boost/chrono/stopwatches/strict_stopwatch.hpp  ------------------------------------------------------------//
   2 //  Copyright 2011 Vicente J. Botet Escriba
   3 //  Copyright (c) Microsoft Corporation 2014
   4 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //  See http://www.boost.org/libs/libs/chrono/stopwatches for documentation.
   7
   8 #ifndef BOOST_CHRONO_STOPWATCHES_STRICT_STOPWATCH__HPP
   9 #define BOOST_CHRONO_STOPWATCHES_STRICT_STOPWATCH__HPP
  10
  11 #include <boost/chrono/config.hpp>
  12
  13 #include <boost/chrono/chrono.hpp>
  14 #include <boost/chrono/detail/system.hpp>
  15 #include <boost/chrono/thread_clock.hpp>
  16 #include <boost/chrono/process_cpu_clocks.hpp>
  17 #include <utility>
  18
  19 namespace boost
  20 {
  21   namespace chrono
  22   {
  23
  24     /**
  25      * This class provides the simpler stopwatch which is just able to give the elapsed time since its construction.
  26      */
  27     template<typename Clock=high_resolution_clock>
  28     class strict_stopwatch
  29     {
  30     public:
  31       typedef Clock clock;
  32       typedef typename Clock::duration duration;
  33       typedef typename Clock::time_point time_point;
  34       typedef typename Clock::rep rep;
  35       typedef typename Clock::period period;
  36       BOOST_STATIC_CONSTEXPR bool is_steady =             Clock::is_steady;
  37
  38
  39       strict_stopwatch() :
  40         start_(clock::now())
  41       {
  42       }
  43 #if !defined BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING
  44       explicit strict_stopwatch(system::error_code & ec) :
  45         start_(duration::zero())
  46       {
  47         time_point tmp = clock::now(ec);
  48         if (!BOOST_CHRONO_IS_THROWS(ec))
  49         {
  50           if (ec)
  51           {
  52             return;
  53           }
  54         }
  55         start_ = tmp;
  56       }
  57 #endif
  58
  59       ~strict_stopwatch() BOOST_NOEXCEPT
  60       {
  61       }
  62
  63       duration elapsed()
  64       {
  65         return clock::now() - start_;
  66       }
  67
  68 #if !defined BOOST_CHRONO_DONT_PROVIDE_HYBRID_ERROR_HANDLING
  69       duration elapsed(system::error_code & ec)
  70       {
  71         time_point tmp = clock::now(ec);
  72         if (!BOOST_CHRONO_IS_THROWS(ec))
  73         {
  74           if (ec)
  75             return duration::zero();
  76         }
  77         return tmp - start_;
  78       }
  79 #endif
  80       /**
  81        * States if the Stopwatch is running.
  82        */
  83       bool is_running() const {
  84         return true;
  85       }
  86     private:
  87       time_point start_;
  88       strict_stopwatch(const strict_stopwatch&); // = delete;
  89       strict_stopwatch& operator=(const strict_stopwatch&); // = delete;
  90     };
  91
  92     typedef strict_stopwatch<system_clock> system_strict_stopwatch;
  93 #ifdef BOOST_CHRONO_HAS_CLOCK_STEADY
  94     typedef strict_stopwatch<steady_clock> steady_strict_stopwatch;
  95 #endif
  96     typedef strict_stopwatch<high_resolution_clock> high_resolution_strict_stopwatch;
  97
  98 #if defined(BOOST_CHRONO_HAS_PROCESS_CLOCKS)
  99     typedef strict_stopwatch<process_real_cpu_clock> process_real_cpu_strict_stopwatch;
 100 #if ! BOOST_OS_WINDOWS || BOOST_PLAT_WINDOWS_DESKTOP
 101     typedef strict_stopwatch<process_user_cpu_clock> process_user_cpu_strict_stopwatch;
 102     typedef strict_stopwatch<process_system_cpu_clock> process_system_cpu_strict_stopwatch;
 103     typedef strict_stopwatch<process_cpu_clock> process_cpu_strict_stopwatch;
 104 #endif
 105 #endif
 106
 107 #if defined(BOOST_CHRONO_HAS_THREAD_CLOCK)
 108     typedef strict_stopwatch<thread_clock> thread_strict_stopwatch;
 109 #endif
 110
 111
 112   } // namespace chrono
 113 } // namespace boost
 114
 115 #endif