rate.cpp
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35  * Author: Eitan Marder-Eppstein
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37 #include <ros/rate.h>
38 
39 namespace ros
40 {
41 
42 Rate::Rate(double frequency)
43 : start_(Time::now())
44 , expected_cycle_time_(1.0 / frequency)
45 , actual_cycle_time_(0.0)
46 { }
47 
49  : start_(Time::now())
50  , expected_cycle_time_(d.sec, d.nsec)
51  , actual_cycle_time_(0.0)
52 { }
53 
55 {
56  Time expected_end = start_ + expected_cycle_time_;
57 
58  Time actual_end = Time::now();
59 
60  // detect backward jumps in time
61  if (actual_end < start_)
62  {
63  expected_end = actual_end + expected_cycle_time_;
64  }
65 
66  //calculate the time we'll sleep for
67  Duration sleep_time = expected_end - actual_end;
68 
69  //set the actual amount of time the loop took in case the user wants to know
70  actual_cycle_time_ = actual_end - start_;
71 
72  //make sure to reset our start time
73  start_ = expected_end;
74 
75  //if we've taken too much time we won't sleep
76  if(sleep_time <= Duration(0.0))
77  {
78  // if we've jumped forward in time, or the loop has taken more than a full extra
79  // cycle, reset our cycle
80  if (actual_end > expected_end + expected_cycle_time_)
81  {
82  start_ = actual_end;
83  }
84  // return false to show that the desired rate was not met
85  return false;
86  }
87 
88  return sleep_time.sleep();
89 }
90 
92 {
93  start_ = Time::now();
94 }
95 
97 {
98  return actual_cycle_time_;
99 }
100 
101 WallRate::WallRate(double frequency)
102 : start_(WallTime::now())
103 , expected_cycle_time_(1.0 / frequency)
104 , actual_cycle_time_(0.0)
105 {}
106 
108 : start_(WallTime::now())
109 , expected_cycle_time_(d.sec, d.nsec)
110 , actual_cycle_time_(0.0)
111 {}
112 
114 {
115  WallTime expected_end = start_ + expected_cycle_time_;
116 
117  WallTime actual_end = WallTime::now();
118 
119  // detect backward jumps in time
120  if (actual_end < start_)
121  {
122  expected_end = actual_end + expected_cycle_time_;
123  }
124 
125  //calculate the time we'll sleep for
126  WallDuration sleep_time = expected_end - actual_end;
127 
128  //set the actual amount of time the loop took in case the user wants to know
129  actual_cycle_time_ = actual_end - start_;
130 
131  //make sure to reset our start time
132  start_ = expected_end;
133 
134  //if we've taken too much time we won't sleep
135  if(sleep_time <= WallDuration(0.0))
136  {
137  // if we've jumped forward in time, or the loop has taken more than a full extra
138  // cycle, reset our cycle
139  if (actual_end > expected_end + expected_cycle_time_)
140  {
141  start_ = actual_end;
142  }
143  return false;
144  }
145 
146  return sleep_time.sleep();
147 }
148 
150 {
151  start_ = WallTime::now();
152 }
153 
155 {
156  return actual_cycle_time_;
157 }
158 
159 }
WallDuration expected_cycle_time_
Definition: rate.h:126
Time representation. May either represent wall clock time or ROS clock time.
Definition: time.h:170
WallDuration cycleTime() const
Get the actual run time of a cycle from start to sleep.
Definition: rate.cpp:154
Rate(double frequency)
Constructor, creates a Rate.
Definition: rate.cpp:42
Time start_
Definition: rate.h:84
Duration representation for use with the WallTime class.
Definition: duration.h:136
Time representation. Always wall-clock time.
Definition: time.h:226
void reset()
Sets the start time for the rate to now.
Definition: rate.cpp:91
WallTime start_
Definition: rate.h:125
Duration expected_cycle_time_
Definition: rate.h:85
bool sleep() const
sleep for the amount of time specified by this Duration. If a signal interrupts the sleep...
Definition: src/time.cpp:468
Duration cycleTime() const
Get the actual run time of a cycle from start to sleep.
Definition: rate.cpp:96
bool sleep()
Sleeps for any leftover time in a cycle. Calculated from the last time sleep, reset, or the constructor was called.
Definition: rate.cpp:54
Duration representation for use with the Time class.
Definition: duration.h:108
static WallTime now()
Returns the current wall clock time.
Definition: src/time.cpp:438
WallDuration actual_cycle_time_
Definition: rate.h:126
static Time now()
Retrieve the current time. If ROS clock time is in use, this returns the time according to the ROS cl...
Definition: src/time.cpp:221
Duration actual_cycle_time_
Definition: rate.h:85
bool sleep() const
sleep for the amount of time specified by this Duration. If a signal interrupts the sleep...
Definition: src/time.cpp:384
void reset()
Sets the start time for the rate to now.
Definition: rate.cpp:149
WallRate(double frequency)
Constructor, creates a Rate.
Definition: rate.cpp:101
bool sleep()
Sleeps for any leftover time in a cycle. Calculated from the last time sleep, reset, or the constructor was called.
Definition: rate.cpp:113


rostime
Author(s): Josh Faust
autogenerated on Mon Jul 27 2020 03:43:45