nucleo_f446re_playground/components/etl/test/test_chrono_clocks.cpp

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com

Documentation: 

Copyright(c) 2025 John Wellbelove

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#include "etl/platform.h"

#include "unit_test_framework.h"

#include "etl/chrono.h"

#include <type_traits>

//*****************************************************************************
// Global clock functions.
//*****************************************************************************
namespace
{
  int nanoseconds  = 0;
  int milliseconds = 0;
  int seconds      = 0;
}

extern "C"
{
  etl::chrono::system_clock::rep etl_get_system_clock()
  {
    return etl::chrono::system_clock::rep(milliseconds);
  }

  etl::chrono::high_resolution_clock::rep etl_get_high_resolution_clock()
  {
    return etl::chrono::high_resolution_clock::rep(nanoseconds);
  }

  etl::chrono::steady_clock::rep etl_get_steady_clock()
  {
    return etl::chrono::steady_clock::rep(seconds);
  }
}

namespace
{
  SUITE(test_chrono_clocks)
  {
    //*************************************************************************
    TEST(test_system_clock)
    {
      using Clock     = etl::chrono::system_clock;
      using TimePoint = etl::chrono::time_point<Clock>;
      using Duration  = ETL_CHRONO_SYSTEM_CLOCK_DURATION;
     
      CHECK_TRUE((std::is_same<TimePoint, Clock::time_point>::value));
      CHECK_TRUE((std::is_same<Duration, Clock::duration>::value));
      CHECK_TRUE((std::is_same<Duration::rep, Clock::duration::rep>::value));
      CHECK_TRUE((std::is_same<Duration::period, Clock::duration::period>::value));
      CHECK_FALSE(Clock::is_steady); // Set in etl_profile.h

      Clock::time_point now;

      milliseconds = 1000;
      now = Clock::now();
      CHECK_EQUAL(1000, now.time_since_epoch().count());

      milliseconds = 2000;
      now = Clock::now();
      CHECK_EQUAL(2000, now.time_since_epoch().count());

      // Convert to seconds.
      etl::time_t time = Clock::to_time_t(now);
      CHECK_EQUAL(2, time);

      // Convert back to a TimePoint.
      TimePoint tp2 = Clock::from_time_t(time);
      CHECK_EQUAL(2000, tp2.time_since_epoch().count());
    }

    //*************************************************************************
    TEST(test_high_resolution_clock)
    {
      using Clock     = etl::chrono::high_resolution_clock;
      using TimePoint = etl::chrono::time_point<Clock>;
      using Duration  = ETL_CHRONO_HIGH_RESOLUTION_CLOCK_DURATION;

      CHECK_TRUE((std::is_same<TimePoint, Clock::time_point>::value));
      CHECK_TRUE((std::is_same<Duration, Clock::duration>::value));
      CHECK_TRUE((std::is_same<Duration::rep, Clock::duration::rep>::value));
      CHECK_TRUE((std::is_same<Duration::period, Clock::duration::period>::value));
      CHECK_TRUE(Clock::is_steady);

      Clock::time_point now;

      nanoseconds = 1;
      now = Clock::now();
      CHECK_EQUAL(1, now.time_since_epoch().count());

      nanoseconds = 2;
      now = Clock::now();
      CHECK_EQUAL(2, now.time_since_epoch().count());
    }

    //*************************************************************************
    TEST(test_steady_clock)
    {
      using Clock     = etl::chrono::steady_clock;
      using TimePoint = etl::chrono::time_point<Clock>;
      using Duration  = ETL_CHRONO_STEADY_CLOCK_DURATION;

      CHECK_TRUE((std::is_same<TimePoint, Clock::time_point>::value));
      CHECK_TRUE((std::is_same<Duration, Clock::duration>::value));
      CHECK_TRUE((std::is_same<Duration::rep, Clock::duration::rep>::value));
      CHECK_TRUE((std::is_same<Duration::period, Clock::duration::period>::value));
      CHECK_TRUE(Clock::is_steady);

      Clock::time_point now;

      seconds = 1;
      now = Clock::now();
      CHECK_EQUAL(1, now.time_since_epoch().count());

      seconds = 2;
      now = Clock::now();
      CHECK_EQUAL(2, now.time_since_epoch().count());
    }

    //*************************************************************************
    TEST(test_clock_cast)
    {      
      using FromClock     = etl::chrono::system_clock;
      using FromTimePoint = etl::chrono::time_point<FromClock>;
      using FromDuration  = FromClock::duration;

      using ToClock     = etl::chrono::steady_clock;
      using ToTimePoint = etl::chrono::time_point<ToClock>;
      using ToDuration  = ToClock::duration;

      FromTimePoint from_tp(FromDuration(1000));

      ToTimePoint to_tp = etl::chrono::clock_cast<ToClock>(from_tp);

      auto num_sys_clock    = FromDuration::period::den;
      auto num_steady_clock = ToDuration::period::num;

      auto sys_clock_count          = from_tp.time_since_epoch().count();
      auto scaled_steady_lock_count = (to_tp.time_since_epoch().count() * num_sys_clock) / num_steady_clock;

      CHECK_EQUAL(sys_clock_count, scaled_steady_lock_count);
    }
  };
}