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/*********************************************************************
*
* Software License Agreement (BSD License)
*
* Copyright (c) 2009, Willow Garage, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of the Willow Garage nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Author: Eitan Marder-Eppstein
*********************************************************************/
#include <ros/rate.h>
namespace rs2rosinternal
{
Rate::Rate(double frequency)
: start_(Time::now())
, expected_cycle_time_(1.0 / frequency)
, actual_cycle_time_(0.0)
{ }
Rate::Rate(const Duration& d)
: start_(Time::now())
, expected_cycle_time_(d.sec, d.nsec)
, actual_cycle_time_(0.0)
{ }
bool Rate::sleep()
{
Time expected_end = start_ + expected_cycle_time_;
Time actual_end = Time::now();
// detect backward jumps in time
if (actual_end < start_)
{
expected_end = actual_end + expected_cycle_time_;
}
//calculate the time we'll sleep for
Duration sleep_time = expected_end - actual_end;
//set the actual amount of time the loop took in case the user wants to know
actual_cycle_time_ = actual_end - start_;
//make sure to reset our start time
start_ = expected_end;
//if we've taken too much time we won't sleep
if(sleep_time <= Duration(0.0))
{
// if we've jumped forward in time, or the loop has taken more than a full extra
// cycle, reset our cycle
if (actual_end > expected_end + expected_cycle_time_)
{
start_ = actual_end;
}
// return false to show that the desired rate was not met
return false;
}
return sleep_time.sleep();
}
void Rate::reset()
{
start_ = Time::now();
}
Duration Rate::cycleTime() const
{
return actual_cycle_time_;
}
WallRate::WallRate(double frequency)
: start_(WallTime::now())
, expected_cycle_time_(1.0 / frequency)
, actual_cycle_time_(0.0)
{}
WallRate::WallRate(const Duration& d)
: start_(WallTime::now())
, expected_cycle_time_(d.sec, d.nsec)
, actual_cycle_time_(0.0)
{}
bool WallRate::sleep()
{
WallTime expected_end = start_ + expected_cycle_time_;
WallTime actual_end = WallTime::now();
// detect backward jumps in time
if (actual_end < start_)
{
expected_end = actual_end + expected_cycle_time_;
}
//calculate the time we'll sleep for
WallDuration sleep_time = expected_end - actual_end;
//set the actual amount of time the loop took in case the user wants to know
actual_cycle_time_ = actual_end - start_;
//make sure to reset our start time
start_ = expected_end;
//if we've taken too much time we won't sleep
if(sleep_time <= WallDuration(0.0))
{
// if we've jumped forward in time, or the loop has taken more than a full extra
// cycle, reset our cycle
if (actual_end > expected_end + expected_cycle_time_)
{
start_ = actual_end;
}
return false;
}
return sleep_time.sleep();
}
void WallRate::reset()
{
start_ = WallTime::now();
}
WallDuration WallRate::cycleTime() const
{
return actual_cycle_time_;
}
}