Crypto++  8.5
Free C++ class library of cryptographic schemes
hrtimer.h
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1 // hrtimer.h - originally written and placed in the public domain by Wei Dai
2 
3 /// \file hrtimer.h
4 /// \brief Classes for timers
5 
6 #ifndef CRYPTOPP_HRTIMER_H
7 #define CRYPTOPP_HRTIMER_H
8 
9 #include "config.h"
10 
11 #if !defined(HIGHRES_TIMER_AVAILABLE) || (defined(CRYPTOPP_WIN32_AVAILABLE) && !defined(THREAD_TIMER_AVAILABLE))
12 #include <time.h>
13 #endif
14 
15 NAMESPACE_BEGIN(CryptoPP)
16 
17 #ifdef HIGHRES_TIMER_AVAILABLE
18  /// \brief TimerWord is a 64-bit word
19  typedef word64 TimerWord;
20 #else
21  /// \brief TimerWord is a clock_t
22  typedef clock_t TimerWord;
23 #endif
24 
25 /// \brief Base class for timers
26 /// \sa ThreadUserTimer, Timer
27 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TimerBase
28 {
29 public:
30  /// \brief Unit of measure
31  /// \details Unit selects the unit of measure as returned by functions
32  /// ElapsedTimeAsDouble() and ElapsedTime().
33  /// \sa ElapsedTimeAsDouble, ElapsedTime
34  enum Unit {
35  /// \brief Timer unit is seconds
36  /// \details All timers support seconds
37  SECONDS = 0,
38  /// \brief Timer unit is milliseconds
39  /// \details All timers support milliseconds
41  /// \brief Timer unit is microseconds
42  /// \details The timer requires hardware support microseconds
44  /// \brief Timer unit is nanoseconds
45  /// \details The timer requires hardware support nanoseconds
46  NANOSECONDS
47  };
48 
49  /// \brief Construct a TimerBase
50  /// \param unit the unit of measure
51  /// \param stuckAtZero flag
52  TimerBase(Unit unit, bool stuckAtZero)
53  : m_timerUnit(unit), m_stuckAtZero(stuckAtZero), m_started(false)
54  , m_start(0), m_last(0) {}
55 
56  /// \brief Retrieve the current timer value
57  /// \return the current timer value
58  virtual TimerWord GetCurrentTimerValue() =0;
59 
60  /// \brief Retrieve ticks per second
61  /// \return ticks per second
62  /// \details TicksPerSecond() is not the timer resolution. It is a
63  /// conversion factor into seconds.
64  virtual TimerWord TicksPerSecond() =0;
65 
66  /// \brief Start the timer
67  void StartTimer();
68 
69  /// \brief Retrieve the elapsed time
70  /// \return the elapsed time as a double
71  /// \details The return value of ElapsedTimeAsDouble() depends upon
72  /// the Unit selected during construction of the timer. For example,
73  /// if <tt>Unit = SECONDS</tt> and ElapsedTimeAsDouble() returns 3,
74  /// then the timer has run for 3 seconds. If
75  /// <tt>Unit = MILLISECONDS</tt> and ElapsedTimeAsDouble() returns
76  /// 3000, then the timer has run for 3 seconds.
77  /// \sa Unit, ElapsedTime
78  double ElapsedTimeAsDouble();
79 
80  /// \brief Retrieve the elapsed time
81  /// \return the elapsed time as an unsigned long
82  /// \details The return value of ElapsedTime() depends upon the
83  /// Unit selected during construction of the timer. For example, if
84  /// <tt>Unit = SECONDS</tt> and ElapsedTime() returns 3, then
85  /// the timer has run for 3 seconds. If <tt>Unit = MILLISECONDS</tt>
86  /// and ElapsedTime() returns 3000, then the timer has run for 3
87  /// seconds.
88  /// \sa Unit, ElapsedTimeAsDouble
89  unsigned long ElapsedTime();
90 
91 private:
92  double ConvertTo(TimerWord t, Unit unit);
93 
94  Unit m_timerUnit; // HPUX workaround: m_unit is a system macro on HPUX
95  bool m_stuckAtZero, m_started;
96  TimerWord m_start, m_last;
97 };
98 
99 /// \brief Measure CPU time spent executing instructions of this thread
100 /// \details ThreadUserTimer requires support of the OS. On Unix-based it
101 /// reports process time. On Windows NT or later desktops and servers it
102 /// reports thread times with performance counter precision.. On Windows
103 /// Phone and Windows Store it reports wall clock time with performance
104 /// counter precision. On all others it reports wall clock time.
105 /// \note ThreadUserTimer only works correctly on Windows NT or later
106 /// desktops and servers.
107 /// \sa Timer
109 {
110 public:
111  /// \brief Construct a ThreadUserTimer
112  /// \param unit the unit of measure
113  /// \param stuckAtZero flag
114  ThreadUserTimer(Unit unit = TimerBase::SECONDS, bool stuckAtZero = false) : TimerBase(unit, stuckAtZero) {}
117 };
118 
119 /// \brief High resolution timer
120 /// \sa ThreadUserTimer
121 class CRYPTOPP_DLL Timer : public TimerBase
122 {
123 public:
124  /// \brief Construct a Timer
125  /// \param unit the unit of measure
126  /// \param stuckAtZero flag
127  Timer(Unit unit = TimerBase::SECONDS, bool stuckAtZero = false) : TimerBase(unit, stuckAtZero) {}
130 };
131 
132 NAMESPACE_END
133 
134 #endif
ThreadUserTimer::ThreadUserTimer
ThreadUserTimer(Unit unit=TimerBase::SECONDS, bool stuckAtZero=false)
Construct a ThreadUserTimer.
Definition: hrtimer.h:114
TimerBase::MICROSECONDS
@ MICROSECONDS
Timer unit is microseconds.
Definition: hrtimer.h:43
ThreadUserTimer::TicksPerSecond
TimerWord TicksPerSecond()
Retrieve ticks per second.
Definition: hrtimer.cpp:159
ThreadUserTimer
Measure CPU time spent executing instructions of this thread.
Definition: hrtimer.h:108
TimerWord
word64 TimerWord
TimerWord is a 64-bit word.
Definition: hrtimer.h:19
word64
unsigned long long word64
64-bit unsigned datatype
Definition: config_int.h:91
TimerBase::MILLISECONDS
@ MILLISECONDS
Timer unit is milliseconds.
Definition: hrtimer.h:40
TimerBase::Unit
Unit
Unit of measure.
Definition: hrtimer.h:34
TimerBase::TicksPerSecond
virtual TimerWord TicksPerSecond()=0
Retrieve ticks per second.
ThreadUserTimer::GetCurrentTimerValue
TimerWord GetCurrentTimerValue()
Retrieve the current timer value.
Definition: hrtimer.cpp:121
TimerBase::TimerBase
TimerBase(Unit unit, bool stuckAtZero)
Construct a TimerBase.
Definition: hrtimer.h:52
TimerBase::GetCurrentTimerValue
virtual TimerWord GetCurrentTimerValue()=0
Retrieve the current timer value.
TimerBase
Base class for timers.
Definition: hrtimer.h:27
TimerBase::SECONDS
@ SECONDS
Timer unit is seconds.
Definition: hrtimer.h:37
CryptoPP
Crypto++ library namespace.
config.h
Library configuration file.
Timer
High resolution timer.
Definition: hrtimer.h:121
Timer::Timer
Timer(Unit unit=TimerBase::SECONDS, bool stuckAtZero=false)
Construct a Timer.
Definition: hrtimer.h:127