rate.cpp
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IN NO EVENT SHALL THE 00026 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 00027 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 00028 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00029 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 00030 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00031 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 00032 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 00033 * POSSIBILITY OF SUCH DAMAGE. 00034 * 00035 * Author: Eitan Marder-Eppstein 00036 *********************************************************************/ 00037 #include <ros/rate.h> 00038 00039 namespace ros 00040 { 00041 00042 Rate::Rate(double frequency) 00043 : start_(Time::now()) 00044 , expected_cycle_time_(1.0 / frequency) 00045 , actual_cycle_time_(0.0) 00046 { } 00047 00048 Rate::Rate(const Duration& d) 00049 : start_(Time::now()) 00050 , expected_cycle_time_(1.0 / d.toSec()) 00051 , actual_cycle_time_(0.0) 00052 { } 00053 00054 00055 00056 bool Rate::sleep() 00057 { 00058 Time expected_end = start_ + expected_cycle_time_; 00059 00060 Time actual_end = Time::now(); 00061 00062 // detect backward jumps in time 00063 if (actual_end < start_) 00064 { 00065 expected_end = actual_end + expected_cycle_time_; 00066 } 00067 00068 //calculate the time we'll sleep for 00069 Duration sleep_time = expected_end - actual_end; 00070 00071 //set the actual amount of time the loop took in case the user wants to know 00072 actual_cycle_time_ = actual_end - start_; 00073 00074 //make sure to reset our start time 00075 start_ = expected_end; 00076 00077 //if we've taken too much time we won't sleep 00078 if(sleep_time <= Duration(0.0)) 00079 { 00080 // if we've jumped forward in time, or the loop has taken more than a full extra 00081 // cycle, reset our cycle 00082 if (actual_end > expected_end + expected_cycle_time_) 00083 { 00084 start_ = actual_end; 00085 } 00086 return true; 00087 } 00088 00089 return sleep_time.sleep(); 00090 } 00091 00092 void Rate::reset() 00093 { 00094 start_ = Time::now(); 00095 } 00096 00097 Duration Rate::cycleTime() const 00098 { 00099 return actual_cycle_time_; 00100 } 00101 00102 WallRate::WallRate(double frequency) 00103 : start_(WallTime::now()) 00104 , expected_cycle_time_(1.0 / frequency) 00105 , actual_cycle_time_(0.0) 00106 {} 00107 00108 WallRate::WallRate(const Duration& d) 00109 : start_(WallTime::now()) 00110 , expected_cycle_time_(1.0 / d.toSec()) 00111 , actual_cycle_time_(0.0) 00112 {} 00113 00114 bool WallRate::sleep() 00115 { 00116 WallTime expected_end = start_ + expected_cycle_time_; 00117 00118 WallTime actual_end = WallTime::now(); 00119 00120 // detect backward jumps in time 00121 if (actual_end < start_) 00122 { 00123 expected_end = actual_end + expected_cycle_time_; 00124 } 00125 00126 //calculate the time we'll sleep for 00127 WallDuration sleep_time = expected_end - actual_end; 00128 00129 //set the actual amount of time the loop took in case the user wants to know 00130 actual_cycle_time_ = actual_end - start_; 00131 00132 //make sure to reset our start time 00133 start_ = expected_end; 00134 00135 //if we've taken too much time we won't sleep 00136 if(sleep_time <= WallDuration(0.0)) 00137 { 00138 // if we've jumped forward in time, or the loop has taken more than a full extra 00139 // cycle, reset our cycle 00140 if (actual_end > expected_end + expected_cycle_time_) 00141 { 00142 start_ = actual_end; 00143 } 00144 return true; 00145 } 00146 00147 return sleep_time.sleep(); 00148 } 00149 00150 void WallRate::reset() 00151 { 00152 start_ = WallTime::now(); 00153 } 00154 00155 WallDuration WallRate::cycleTime() const 00156 { 00157 return actual_cycle_time_; 00158 } 00159 00160 00161 }