µOS++ IIIe Reference  v6.3.15
“Perfekt ist nicht gut genug”
The third edition of µOS++, a POSIX inspired open source system, written in C++.
chrono.cpp
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1 /*
2  * This file is part of the µOS++ distribution.
3  * (https://github.com/micro-os-plus)
4  * Copyright (c) 2016 Liviu Ionescu.
5  *
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27 
28 #include <cmsis-plus/rtos/os.h>
29 #include <cmsis-plus/estd/chrono>
30 
31 // ----------------------------------------------------------------------------
32 
33 namespace os
34 {
35  namespace estd
36  {
37  namespace chrono
38  {
39 
40  // ----------------------------------------------------------------------
41 
42  using namespace os;
43 
44  // Number of seconds from epoch (1 January 1970 00:00:00 UTC)
45  // when the system was started.
46  // Must be set during startup by reading the RTC.
47  // uint64_t startup_absolute_seconds;
48 
49 #pragma GCC diagnostic push
50 #pragma GCC diagnostic ignored "-Waggregate-return"
51 
52  // ======================================================================
53 
55  systick_clock::now () noexcept
56  {
57  const auto ticks = rtos::sysclock.now ();
58  return time_point
59  { duration
60  { ticks } };
61  }
62 
63  // ======================================================================
64 
66  realtime_clock::now () noexcept
67  {
68  const auto secs = rtos::rtclock.now ();
69  return time_point
70  { duration
71  { secs } };
72  }
73 
75 
76  // ======================================================================
77 
79  system_clock::now () noexcept
80  {
81  const auto ticks = rtos::sysclock.now ();
82  return time_point
83  { duration
84  { systicks
85  { ticks } + realtime_clock::startup_time_point.time_since_epoch () //
86  } //
87  };
88  }
89 
90  time_t
91  system_clock::to_time_t (const time_point& t) noexcept
92  {
93  return time_t (
94  std::chrono::duration_cast<std::chrono::seconds> (
95  t.time_since_epoch ()).count ());
96  }
97 
99  system_clock::from_time_t (time_t t) noexcept
100  {
101  return system_clock::time_point (std::chrono::seconds (t));
102  }
103 
104  // ======================================================================
105 
108  {
109  auto cycles = rtos::hrclock.now ();
110 
111  // The duration is the number of sum of SysTick ticks plus the current
112  // count of CPU cycles (computed from the SysTick counter).
113  // Notice: a more exact solution would be to compute
114  // ticks * divisor + cycles, but this severely reduces the
115  // range of ticks.
116  return time_point
117  { duration
118  { duration
119  { cycles * 1000000000ULL
121  + realtime_clock::startup_time_point.time_since_epoch () } //
122  };
123  }
124 
125 #pragma GCC diagnostic pop
126 
127  // ------------------------------------------------------------------------
128 
129  } /* namespace chrono */
130  } /* namespace estd */
131 } /* namespace os */
132 
133 // ----------------------------------------------------------------------------
std::chrono::duration< rep, period > duration
basic duration type of clock
Definition: chrono:138
std::chrono::time_point< system_clock > time_point
Definition: chrono:177
static time_t to_time_t(const time_point &tp) noexcept
Definition: chrono.cpp:91
std::chrono::time_point< realtime_clock > time_point
Definition: chrono:141
System namespace.
systick_clock::duration systicks
Definition: chrono:108
clock_highres hrclock
The high resolution clock object instance.
Definition: os-clocks.cpp:717
clock_rtc rtclock
The real time clock object instance.
Definition: os-clocks.cpp:660
static time_point now() noexcept
Definition: chrono.cpp:66
Single file µOS++ RTOS definitions.
clock_systick sysclock
The system clock object instance.
Definition: os-clocks.cpp:551
uint32_t input_clock_frequency_hz(void)
Definition: os-clocks.h:905
std::chrono::time_point< systick_clock > time_point
basic time_point type of clock
Definition: chrono:87
std::chrono::duration< rep, period > duration
basic duration type of clock
Definition: chrono:84
static time_point now() noexcept
Definition: chrono.cpp:107
static time_point from_time_t(time_t t) noexcept
Definition: chrono.cpp:99
std::chrono::time_point< high_resolution_clock > time_point
Definition: chrono:212
std::chrono::microseconds duration
Definition: chrono:174
virtual timestamp_t now(void) override
Tell the current time.
Definition: os-clocks.cpp:760
virtual timestamp_t now(void) override
Tell the current time adjusted for epoch.
Definition: os-clocks.cpp:419
std::chrono::nanoseconds duration
Definition: chrono:209
static time_point now() noexcept
Definition: chrono.cpp:79
static time_point startup_time_point
Definition: chrono:161
static time_point now() noexcept
Definition: chrono.cpp:55
virtual timestamp_t now(void)
Tell the current time, possibly adjusted for epoch.
Definition: os-clocks.cpp:169