/*
 * This file is part of the µOS++ distribution.
 *   (https://github.com/micro-os-plus)
 * Copyright (c) 2017 Liviu Ionescu.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef SYSCLOCK_H_
#define SYSCLOCK_H_

#include <stdint.h>

// ----------------------------------------------------------------------------

namespace os 
{
  class sysclock;
  extern class sysclock sysclock;
}

// ----------------------------------------------------------------------------

namespace os 
{

  /*
  * These classes are super simple versions of the µOS++ clocks.
  */

  class clock
  {
  public:

    using duration_t = uint32_t;
    using timestamp_t = uint64_t;
  };

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpadded"

  class sysclock : public clock
  {
  public:
    static constexpr uint32_t frequency_hz = 1000;

    sysclock (void);

    timestamp_t
    steady_now (void);

    /**
     * @param duration ticks based on frequency_hz.
     */
    void
    sleep_for (duration_t duration);

    void
    internal_increment_count ();

  private:
    timestamp_t volatile steady_count_ = 0;
  };

#pragma GCC diagnostic pop

}

inline void
__attribute__((always_inline))
os::sysclock::internal_increment_count ()
{
  ++steady_count_;
}

inline os::clock::timestamp_t
__attribute__((always_inline))
os::sysclock::steady_now (void)
{
  return steady_count_;
}

// ----------------------------------------------------------------------------

#endif /* SYSCLOCK_H_ */