Time-Portable Real-Time Programming with Exotasksck/content/talks/UCB07-Exotasks.pdfTime-Portable...
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Time-Portable Real-Time Programming with Exotasks Christoph Kirsch Universität Salzburg Joint work with J. Auerbach, D. Bacon, D. Iercan, V.T. Rajan, H. Röck, and R. Trummer CHESS Seminar, UC Berkeley, February 2007
Transcript of Time-Portable Real-Time Programming with Exotasksck/content/talks/UCB07-Exotasks.pdfTime-Portable...
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Time-Portable Real-TimeProgramming with Exotasks
Christoph KirschUniversität Salzburg
Joint work with J. Auerbach, D. Bacon, D. Iercan,V.T. Rajan, H. Röck, and R. Trummer
CHESS Seminar, UC Berkeley, February 2007
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© C. Kirsch 2007 2
Exotask Eclipse PluginExotaskGraph
Specification
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Exotask Eclipse Plugin
Exotask
Exotask
Exotask
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Exotask Eclipse Plugin
Connection Connection
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Exotask Eclipse PluginTiming
Grammar
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Exotasks in Java
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public class Controller implements Runnable { // Code generated from the specification: private ExotaskInputPort in0; private ExotaskOutputPort out0; public Controller(ExotaskInputPort in0, ExotaskOutputPort out0) { this.in0 = in0; this.out0 = out0; } // Code written by the user: public void run() { double[] sensorData = (double[]) in0.getValue(); out0.setValue( new Double(control(sensorData))); } private double control(double[] sensors) { ... the actual control algorithm ... }}
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TT Grammar
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TT Grammar
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Period
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TT Grammar
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TimeOffset
TimeOffset
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Logical Execution Time
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Plant
Control System
SensorTask
Actuator
Logical Execution Time
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Actual Execution Time
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Plant
Control System
Sensor
Deadline
ActuatorTask
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Actual Execution Time
0 1 2 3 4 5 6 7 8 9 10
Plant
Control System
Sensor
Deadline
ActuatorTask
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Time PortabilityPlant
Control System
A system’s I/O behavior is input-determined if,for all sequences I of input values and times,
the system always producesunique sequences f(I) of output values and times.
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Exotask Isolation
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Private Heaps
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1. Validate, 2. Instantiate,3. Schedule & Execute
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Exotask Runtime System
public class Controller implements Runnable { // Code generated from the specification: private ExotaskInputPort in0; private ExotaskOutputPort out0; public Controller(ExotaskInputPort in0, ExotaskOutputPort out0) { this.in0 = in0; this.out0 = out0; } // Code written by the user: public void run() { double[] sensorData = (double[]) in0.getValue(); out0.setValue( new Double(control(sensorData))); } private double control(double[] sensors) { ... the actual control algorithm ... }}Exotask Graph
Exotask CodeExotask GraphSpecification
schedule execute
instantiatevalidate
invokes
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The JAviator
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50Hz Hard Real Time
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JAviator Controller
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Control Terminal
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Control Terminal Exotask Controller
Demo
Mock JAviator
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IBM’s TuningFork
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TuningFork InstrumentedExotask System
Experiments
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No GC in Progress
17~3ms
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During GC
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1.4GHz Laptop
19~4ms
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Clamp-free Hover
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Thank you
