// -*- C++ -*- */
// $Id: High_Res_Timer.inl 95798 2012-05-31 07:58:55Z johnnyw $

#include "ace/Global_Macros.h"

#if defined (ACE_WIN32)
#  include "ace/OS_NS_sys_time.h"
#endif /* ACE_WIN32 */

ACE_BEGIN_VERSIONED_NAMESPACE_DECL

/// Be very careful before changing the calculations inside
/// ACE_High_Res_Timer. The precision matters and we are using integer
/// calculations not floating point.
ACE_INLINE void
ACE_High_Res_Timer::hrtime_to_tv (ACE_Time_Value &tv,
                                  const ACE_hrtime_t hrt)
{
#if !defined (ACE_WIN32)
    // The following are based on the units of global_scale_factor_
    // being 1/microsecond.  Therefore, dividing by it converts
    // clock ticks to microseconds.
    tv.sec ((time_t) (hrt / (ACE_UINT32) ACE_HR_SCALE_CONVERSION /
                  global_scale_factor ()));

    // hrt = (tv.sec * ACE_ONE_SECOND_IN_USECS + tv.usec) * global_scale_factor_
    // tv.usec = hrt / global_scale_factor_ - tv.sec * ACE_ONE_SECOND_IN_USECS
    // That first term will be lossy, so factor out global_scale_factor_:
    // tv.usec = (hrt - tv.sec * ACE_ONE_SECOND_IN_USECS * global_scale_factor_)/
    //           global_scale_factor
    ACE_hrtime_t tmp = tv.sec ();
    tmp *= ((ACE_UINT32) ACE_HR_SCALE_CONVERSION * global_scale_factor ());
    tv.usec ((suseconds_t) ((hrt - tmp) / global_scale_factor ()));
#else
    // This a higher-precision version, specific for Windows systems
    // The following are based on the units of global_scale_factor_
    // being 1/microsecond.  Therefore, dividing by it converts
    // clock ticks to microseconds.
    tv.sec ((time_t) (hrt / global_scale_factor () ));

    // Calculate usec, first calculate the seconds in hrtime
    ACE_High_Res_Timer::global_scale_factor_type tmp = tv.sec ();
    tmp *= global_scale_factor ();
    tv.usec ((suseconds_t) ((hrt - tmp) * ACE_HR_SCALE_CONVERSION / global_scale_factor ()));
#endif
}


ACE_INLINE ACE_Time_Value
ACE_High_Res_Timer::gettimeofday (const ACE_OS::ACE_HRTimer_Op op)
{
#if defined (ACE_WIN32)
  // Get the global scale factor if there isn't one yet.
  if (ACE_High_Res_Timer::global_scale_factor_status_ == 0)
    ACE_High_Res_Timer::global_scale_factor ();

  // If there isn't a high-res timer, use gettimeofday ();
  if (ACE_High_Res_Timer::global_scale_factor_status_ == -1)
    return ACE_OS::gettimeofday ();
#endif /* ACE_WIN32 */

  ACE_Time_Value tv;
  ACE_High_Res_Timer::hrtime_to_tv (tv, ACE_OS::gethrtime (op));
  return tv;
}

/// Get the current high res timer as the time of day. This is intended
/// to be used for a gettimeofday replacement in ACE_Timer_Queue and
/// derived classes so the timers will be based on high res timers rather
/// than wall clock time. It uses the ACE_High_Res_Timer::gettimeofday
/// function, which is deprecated. If it gets removed, please move the
/// code down here, intact.
ACE_INLINE ACE_Time_Value
ACE_High_Res_Timer::gettimeofday_hr (void)
{
  return ACE_High_Res_Timer::gettimeofday ();
}


ACE_INLINE ACE_hrtime_t
ACE_High_Res_Timer::gettime (const ACE_OS::ACE_HRTimer_Op op)
{
#if defined (ACE_WIN32)
  // Get the global scale factor if there isn't one yet.
  if (ACE_High_Res_Timer::global_scale_factor_status_ == 0)
    ACE_High_Res_Timer::global_scale_factor ();

  // If there isn't a high-res timer, use gettimeofday ();
  if (ACE_High_Res_Timer::global_scale_factor_status_ == -1)
    {
      ACE_Time_Value const tv = ACE_OS::gettimeofday ();
      // Return the time in microseconds because the global_scale_factor_
      // is 1.
      return tv.sec () * ACE_ONE_SECOND_IN_USECS + tv.usec ();
    }
#endif /* ACE_WIN32 */

  return ACE_OS::gethrtime (op);
}

ACE_INLINE ACE_hrtime_t
ACE_High_Res_Timer::elapsed_hrtime (const ACE_hrtime_t end,
                                    const ACE_hrtime_t start)
{
  if (end > start)
    return end - start;
  return (~start + 1 + end);     // Wrapped-around counter diff
}

ACE_INLINE
ACE_High_Res_Timer::~ACE_High_Res_Timer (void)
{
}

ACE_INLINE void
ACE_High_Res_Timer::start (const ACE_OS::ACE_HRTimer_Op op)
{
  ACE_TRACE ("ACE_High_Res_Timer::start");
  this->start_ = ACE_High_Res_Timer::gettime (op);
}

ACE_INLINE void
ACE_High_Res_Timer::stop (const ACE_OS::ACE_HRTimer_Op op)
{
  ACE_TRACE ("ACE_High_Res_Timer::stop");
  this->end_ = ACE_High_Res_Timer::gettime (op);
}

ACE_INLINE void
ACE_High_Res_Timer::start_incr (const ACE_OS::ACE_HRTimer_Op op)
{
  ACE_TRACE ("ACE_High_Res_Timer::start_incr");
  this->start_incr_ = ACE_High_Res_Timer::gettime (op);
}

ACE_INLINE void
ACE_High_Res_Timer::stop_incr (const ACE_OS::ACE_HRTimer_Op op)
{
  ACE_TRACE ("ACE_High_Res_Timer::stop_incr");
  this->total_ +=
    ACE_High_Res_Timer::elapsed_hrtime (ACE_High_Res_Timer::gettime (op),
                                        this->start_incr_);
}

ACE_INLINE void
ACE_High_Res_Timer::elapsed_microseconds (ACE_hrtime_t &usecs) const
{

#if !defined (ACE_WIN32)
  ACE_hrtime_t elapsed = ACE_High_Res_Timer::elapsed_hrtime (this->end_,
                                                             this->start_);
  usecs = (ACE_hrtime_t) (elapsed / global_scale_factor ());
#else
  usecs = (ACE_High_Res_Timer::elapsed_hrtime (this->end_, this->start_) *
           ACE_HR_SCALE_CONVERSION) /
          global_scale_factor ();
#endif
}

ACE_INLINE void
ACE_High_Res_Timer::global_scale_factor (
    ACE_High_Res_Timer::global_scale_factor_type gsf)
{
  global_scale_factor_ = gsf;
}

ACE_END_VERSIONED_NAMESPACE_DECL
