Maslab Software 2010

Transcription

1 Maslab Software 2010 Bhaskar Mookerji (and Maslab staff of yesteryear) Mobile Autonomous Systems Laboratory 6 January 2010 Bhaskar Mookerji (MIT) Software January / 26

2 Outline 1 Development Cycle Basic Ideas Example: Finite State Machine 2 Useful Java Tools Build Tools ant Debugging jdb Unit Testing junit 3 Miscellaneous Java libraries in python jython Version Control git and svn Performance Issues 4 Conclusions Bhaskar Mookerji (MIT) Software January / 26

3 Outline Development Cycle Basic Ideas 1 Development Cycle Basic Ideas Example: Finite State Machine 2 Useful Java Tools Build Tools ant Debugging jdb Unit Testing junit 3 Miscellaneous Java libraries in python jython Version Control git and svn Performance Issues 4 Conclusions Bhaskar Mookerji (MIT) Software January / 26

4 Development Cycle Basic Ideas Implementation Sequence 1 Open a text editor to edit a source code file. 2 Write class declaration, method declarations, annotated with comments. 3 Fill in source code. 4 Compile. 5 Fix compile errors and repeat compilation until successful. 6 Run and debug behaviors. 7 Back up files into version control. emacs MyExample.java Adjust your /.emacs file Bhaskar Mookerji (MIT) Software January / 26

5 Development Cycle Basic Ideas Implementation Sequence 1 Open a text editor to edit a source code file. 2 Write class declaration, method declarations, annotated with comments. 3 Fill in source code. 4 Compile. 5 Fix compile errors and repeat compilation until successful. 6 Run and debug behaviors. 7 Back up files into version control. Bhaskar Mookerji (MIT) Software January / 26

6 Development Cycle Basic Ideas Implementation Sequence 1 Open a text editor to edit a source code file. 2 Write class declaration, method declarations, annotated with comments. 3 Fill in source code. 4 Compile. 5 Fix compile errors and repeat compilation until successful. 6 Run and debug behaviors. 7 Back up files into version control. Java API APIs for Maslab, OrcBoard Sun s Java Tutorial Ed Faulkner s Java Reference Bhaskar Mookerji (MIT) Software January / 26

7 Development Cycle Basic Ideas Implementation Sequence 1 Open a text editor to edit a source code file. 2 Write class declaration, method declarations, annotated with comments. 3 Fill in source code. 4 Compile. 5 Fix compile errors and repeat compilation until successful. 6 Run and debug behaviors. 7 Back up files into version control. javac MyExample.java Produces MyExample.class if successful make, Ant Bhaskar Mookerji (MIT) Software January / 26

8 Development Cycle Basic Ideas Implementation Sequence 1 Open a text editor to edit a source code file. 2 Write class declaration, method declarations, annotated with comments. 3 Fill in source code. 4 Compile. 5 Fix compile errors and repeat compilation until successful. 6 Run and debug behaviors. 7 Back up files into version control. Bhaskar Mookerji (MIT) Software January / 26

9 Development Cycle Basic Ideas Implementation Sequence 1 Open a text editor to edit a source code file. 2 Write class declaration, method declarations, annotated with comments. 3 Fill in source code. 4 Compile. 5 Fix compile errors and repeat compilation until successful. 6 Run and debug behaviors. 7 Back up files into version control. BotClient, OrcSpy jdb, junit Bhaskar Mookerji (MIT) Software January / 26

10 Development Cycle Basic Ideas Implementation Sequence 1 Open a text editor to edit a source code file. 2 Write class declaration, method declarations, annotated with comments. 3 Fill in source code. 4 Compile. 5 Fix compile errors and repeat compilation until successful. 6 Run and debug behaviors. 7 Back up files into version control. svn, cvs Bhaskar Mookerji (MIT) Software January / 26

11 Development Cycle Basic Ideas Design Principles Motivation Coding a Maslab Robot is a formidable, multi-person project. Good design is critical! This ensures... easier debugging. different team members code all work together. one person s changes doesn t break another team member s code. Bhaskar Mookerji (MIT) Software January / 26

12 Development Cycle Modularity and Design Basic Ideas Modular design... provides abstraction. gives up fine-control abilities, but makes code much more manageable. The design process requires... top-down vs. bottom-up thinking. specifications for each module. implementation for modules. testing each module separately as it is being written. testing overall system for functionality. Bhaskar Mookerji (MIT) Software January / 26

13 Development Cycle Example: Finite State Machine Robot Update(): void GetFSM(): StateMach. <parameter> owner PreviousState StateMachine<Robot> SetGlobalState(State* ): void SetCurrentState(State*): void Update(Robot* ): void ChangeState(State*): void Revert2Previous(Robot*): void CurrentState GlobalState GlobalState CurrentState Execute(Owner*) Execute(Owner*) State<Robot> Enter(Robot* ): void Execute(Robot*): void Exit(Robot* ): void aglobalstate<robot> Enter(Robot* ): void Execute(Robot*): void Exit(Robot* ): void Wander<Robot> Enter(Robot* ): void Execute(Robot*): void Exit(Robot* ): void Turning<Robot> Enter(Robot* ): void Execute(Robot*): void Exit(Robot* ): void FetchingBall<Robot> Enter(Robot* ): void Execute(Robot*): void Exit(Robot* ): void uorc Actions Bhaskar Mookerji (MIT) Software January / 26

14 Development Cycle Writing Good Specifications Example: Finite State Machine Into each specification there should be... a synopsis of classes and methods. how methods are called. restrictions on argument values. the return value and effect of calling the method. Avoid... code implementation details. lengthy discourse. Bhaskar Mookerji (MIT) Software January / 26

15 Outline Useful Java Tools Build Tools ant 1 Development Cycle Basic Ideas Example: Finite State Machine 2 Useful Java Tools Build Tools ant Debugging jdb Unit Testing junit 3 Miscellaneous Java libraries in python jython Version Control git and svn Performance Issues 4 Conclusions Bhaskar Mookerji (MIT) Software January / 26

16 Useful Java Tools Build Tools ant ant is Sun s build system for Java executables. If you re not aware already, there s a sample.xml build file at 1 It includes options for ant build/clean/upload. 2 Consider making different options for running your robot. Good tutorials at with some additional discussion on library dependencies Bhaskar Mookerji (MIT) Software January / 26

17 Useful Java Tools Build Tools ant <! Oh man! you can d e f i n e v a r i a b l e s! > < p r o p e r t y name= " robotip " value= " " / > < p r o p e r t y name= " d e s t D i r " value= " / home / maslab " / > < p r o p e r t y name= " username " value= " maslab " / > < t a r g e t name= " b u i l d " > <! This does deep dependency checking on class f i l e s > <depend s r c d i r = ". " cache= " depcache " closure=" t r u e " / > <! This compiles a l l the java > <javac s r c d i r = ". " i n c l u d e s = " /. java " debug= " t r u e " classpath=" / mit / / / maslab. j a r :. " / > < / t a r g e t > <!... and a l l s o r t s of shorthand > < t a r g e t name= " upload " depends= " b u i l d " > <exec executable= " rsync " > <arg l i n e = " e ssh avr. ${ username }@${ robotip } : ${ d e s t D i r } " / > < / exec> < / t a r g e t > Bhaskar Mookerji (MIT) Software January / 26

18 Useful Java Tools Debugging jdb jdb allows in-line debugging of Java applications. There are two ways of doing this. 1 Running jdb to launch a Java application and start a debug session on that application. 2 Running jdb to connect to a separately launched Java application and start a debug session on that application. Resources: 1 Great tutorials: javaqa/ /04-qa-0623-jdb.html 2 More detailed: 3 Sun Reference: tooldocs/solaris/jdb.html Bhaskar Mookerji (MIT) Software January / 26

19 An example Useful Java Tools Debugging jdb > jdb TestMe > I n i t i a l i z i n g jdb... > 0 xaa:class<testme> > methods TestMe void main ( java. lang. S t r i n g [ ] ) void < i n i t > ( ) i n t g e t I n t _ v a l u e ( ) java. lang. S t r i n g g e t S t r i n g _ v a l u e ( ) void s e t I n t _ v a l u e ( i n t ) void s e t S t r i n g _ v a l u e ( java. lang. S t r i n g ) java. lang. S t r i n g t o S t r i n g ( ) > stop i n TestMe. main Breakpoint set i n javaworld. TestMe. main > run run javaworld. TestMe running Bhaskar Mookerji... (MIT) Software January / 26

20 An example Useful Java Tools Debugging jdb main [ 1 ] l i s t 6 p r i v a t e S t r i n g s t r i n g _ v a l u e ; 7 8 p u b l i c s t a t i c void main ( S t r i n g [ ] args ) 9 { 10 => TestMe testme = new TestMe ( ) ; 11 testme. s e t I n t _ v a l u e ( 1 ) ; 12 testme. s e t S t r i n g _ v a l u e ( " t e s t " ) ; i n t i n t e g e r = testme. g e t I n t _ v a l u e ( ) ; main [ 1 ] main [ 1 ] step main [ 1 ] Breakpoint h i t : javaworld. TestMe. < i n i t > ( TestMe:20 ) main [ 1 ] l o c a l s Method arguments: Local v a r i a b l e s : t Bhaskar h i s Mookerji = S t (MIT) r i n g v a l u e : n usoftware l l i n2010 t v a l u e : 0 6 January / 26

21 Useful Java Tools Unit Testing junit junit allows you to check the expected results of specific program execution routines and inputs. Resources: 1 Cookbook example: http: //junit.sourceforge.net/doc/cookbook/cookbook.htm 2 Detailed tutorial: documentation/tutorials/docsystem/build/ tutorials/junit/junit.html Bhaskar Mookerji (MIT) Software January / 26

22 Usage Useful Java Tools Unit Testing junit Steps are basic... 1 Annotate a method 2 When you want to check a value, import org.junit.assert.* statically, call asserttrue() and pass a boolean that is true if the test succeeds. Checking that an add method public void simpleadd ( ) { Money m12chf= new Money(12, "CHF" ) ; Money m14chf= new Money(14, "CHF" ) ; Money expected= new Money(26, "CHF" ) ; Money r e s u l t = m12chf. add (m14chf) ; asserttrue ( expected. equals ( r e s u l t ) ) ; } Run with java org.junit.runner.junitcore TestClass.class Bhaskar Mookerji (MIT) Software January / 26

23 Outline Miscellaneous Java libraries in python jython 1 Development Cycle Basic Ideas Example: Finite State Machine 2 Useful Java Tools Build Tools ant Debugging jdb Unit Testing junit 3 Miscellaneous Java libraries in python jython Version Control git and svn Performance Issues 4 Conclusions Bhaskar Mookerji (MIT) Software January / 26

24 Miscellaneous Java libraries in python jython What if I want to program in Python? Rumors of pyorc have been greatly exaggerated. You can use the JVM implementation of Python to import Java uorc libraries into a Python environment... import orc. ; import orc. camera. ; public class CameraRobot { } public s t a t i c void main ( S t r i n g args [ ] ) { Camera cam = Camera. makecamera ( ) ; BufferedImage img = cam. capture ( ) ; } Bhaskar Mookerji (MIT) Software January / 26

25 Miscellaneous Java libraries in python jython What if I want to program in Python?... and use this instead: from o r c. camera import Camera as cam from java. awt import imag as imag cam = Camera. makecamera ( ) img = cam. capture ( ) Bhaskar Mookerji (MIT) Software January / 26

26 Miscellaneous Java libraries in python jython Advantages: Concise, dynamically-typed, interpreted language High-level data types Shorter code, faster development time Disadvantages: Dude, aren t interpreted languages slow? 1 Benchmarks: 1 CPython 2.3 and Jython: 75% slower. 2 CPython 2.3 and JVM 1.4: 1 10 times slower. 2 Choose your battles with computationally intensive tasks. Slightly unknown territory for the staff Problems with dependencies and data types in Java Bhaskar Mookerji (MIT) Software January / 26

27 Miscellaneous Java libraries in python jython Jython Resources Jython: Python: Introduction: http: //onjava.com/pub/a/onjava/2002/03/27/jython.html Examples: DocumentationAndEducation Library: Tutorials: Library Reference: Searchable quick reference: Bhaskar Mookerji (MIT) Software January / 26

28 svn Miscellaneous Version Control git and svn Subversion tracks saved changes to your code. Please use it. Changes are locally in a database and then committed/altered: svn help [<command>] svn add/delete/move svn mkdir svn commit (co) -m <msg> svn update (up) svn info/list Resources: 1 Plug-in Integration with Eclipse: 2 Plug-in Integration with Windows Explorer: 3 Command-line tutorial: tutorial/subversion-with-mac-os-x Bhaskar Mookerji (MIT) Software January / 26

29 Miscellaneous Performance Issues Be Mindful of Performance Issues Software CPU bottleneck: Image processing Minimize raw image passes Downsampleing Hardware Camera Capture Frequency Motor Slew Rate Bhaskar Mookerji (MIT) Software January / 26

30 Outline Conclusions 1 Development Cycle Basic Ideas Example: Finite State Machine 2 Useful Java Tools Build Tools ant Debugging jdb Unit Testing junit 3 Miscellaneous Java libraries in python jython Version Control git and svn Performance Issues 4 Conclusions Bhaskar Mookerji (MIT) Software January / 26

31 Conclusions Take-home Messages Test constantly. Start small, build up. Modularity. Avoid over-abstraction. Use software tools at your disposal (svn, debugging, etc.). Knuth: We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Bhaskar Mookerji (MIT) Software January / 26

32 Done! Conclusions Questions? Java threads lecture tomorrow! More online resources: 1 State machine diagram from Programming Game AI by Example at libraries.mit.edu/get/books24x7. 2 Books on software development at Assignment 3: Your (peg) robot should be able to turn itself until it sees a red ball, drive up to it, stop, and publish something to the BotClient. Find a staff member to show them that your robot can do this. Bhaskar Mookerji (MIT) Software January / 26