SPINNERa concurrent language for programming SPIN

William Beaver

Marc Eaddy

Gaurav Khandpur

Sangho Shin

Outline

• Motivation for SPINNER

• Key Features

• Examples

• Compiler Design Overview

• Simulator and Concurrency Complexity

• Test Process

• Lessons Learned

• Closing

What is SPIN?

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Physical System Overview

SPINNERcompiler

SPINscript

SPIN

SPINNERprogram

SPINscript challenge

• Spin disc 1 clockwise 10 revs in 10 sec

• Wait 5 secs• Spin disc 4 at 3 rev/sec• Wait 3 secs• When disc 1 stops

– Spin disc 1 counterclockwise 3 revs in 3.25 sec

– Spin disc 3 clockwise 3 revs in 3.25 secs

(Imagine a Loop!)

Expressiveness vs. complexity

SPINscript challenge

• Spin disc 1 clockwise 10 revs in 10 sec

• Wait 5 secs• Spin disc 4 at 3 rev/sec• Wait 3 secs• When disc 1 stops

– Spin disc 1 counterclockwise 3 revs in 3.25 sec

– Spin disc 3 clockwise 3 revs in 3.25 secs

(Imagine a Loop!)

1, 1-line 10 10000;1, --wait-- 5000;1, 4-speed 3.0 0;1, --wait-- 3000;1, --wait-- 2000;1, 1-line 7 3250;1, 3-line 12 3250;1, --wait-- 3250;

Expressiveness vs. complexity

Key SPINNER improvements

• Concurrency model

• SPIN state maintenance Query state

• User defined functions/libraries

• Typical language “stuff” (control flow, variables, etc.)

• Increased expressiveness and control

SPINNER Syntax• Script like language: sequential from top (no Main)• Literals: double, boolean, string, null• Variables: double, boolean, array (no strings)• Operators: postfix incr/decr, unary not, *, / , %, +, -, <, >,

<=, >=, and, or• Function Definitions: type func func_name (args){}• Built-in functions: seek, setSpeed, getSpeed, getPosition,

wait, waitUntil, getTime, getSize, plus getter/setters for audio parameters, disc setup, etc.

• Import external function libraries• Control Flow: If/then/else, while, repeat/until, for, break

• Concurrency operator: ||

Examples

• Simple

createDiscs(6);

setFile(“all”,“AelonsHarp”);

setGain(“all”, 0.7);

seek(1,2,4000);

seek(6,-2,4000);

wait(4000);

Examples

• Simple

createDiscs(6);

setFile(“all”,“AelonsHarp”);

setGain(“all”, 0.7);

seek(1,2,4000);

seek(6,-2,4000);

wait(4000);

• More Complicated

//assume all setup donefor(i=1;i<=getDiscsSize();i++){

wait(i*1000); seek(i, i*2, i*1000);}waitUntil(getSpeed(1)<=0);

for(i=getDiscsSize();i>0;i--){wait(i*1000);

seek(i, i*2, i*1000);}

Compiler Architecture

SPINNERcompiler

SPINscript

SPIN

Interpreter

SemanticAnalyzer

Parser

Lexer

Simulator

Preprocessor

SpinnerAST

Environment.java

ANTLR

Return type

Name

Args

Symbol Table

Return type

Name

Args

Symbol Table

Return type

Name

Args

Symbol Table

BuiltInFunctionTable

UserDefinedFunctionTable

MainSymbolTable

Function ObjectFunction table

Function table

OuterSymbolTablePtr

InnerSymbolTables

Symbol table

CurrentSymbolTable

Function Object

Return type

Name

Args

Body

Symbol Table

Return type

Name

Args

Symbol Table

Type Name Value

Array info etc..

Type Name Value

Array info etc..

Variable Object

Variable Object

Environment

AST

Environment.java

Symbol Table

OuterSymbolTablePtr

InnerSymbolTables

D a 0

B b T

MainSymbolTable

Environmentdouble a:=0;

boolean b:=true

if (a=0) {

double a;

boolean b;

}

while(b) {

double c;

boolean d;

}

CurrentSymbolTable

Symbol Table

OuterSymbolTablePtr

InnerSymbolTables

D a 0

B b T

OuterSymbolTablePtr

InnerSymbolTables

D a 0

B b F

MainSymbolTable

Environmentdouble a:=0;

boolean b:=true

if (a=0) {

double a;

boolean b;

}

while(b) {

double c;

boolean d;

}

CurrentSymbolTable

Symbol Table

OuterSymbolTablePtr

InnerSymbolTables

D c 0

B d F

OuterSymbolTablePtr

InnerSymbolTables

D a 0

B b T

OuterSymbolTablePtr

InnerSymbolTables

D a 0

B b F

MainSymbolTable

Environmentdouble a:=0;

boolean b:=true

if (a=0) {

double a;

boolean b;

}

while(b) {

double c;

boolean d;

}

CurrentSymbolTable

SPINNERcompiler

SPINscript

SPIN

Interpreter

SemanticAnalyzer

Parser

Lexer

Simulator

Preprocessor

ANTLR You are now here

The Backend: Interpreter and Simulator

Example: t = 15.353 seconds

Simulator.java• Maintains the state of the n-discs at any point

in time during the simulation (“so you don’t have to!”)

• Implements built-ins for setting/getting disc speed, position, etc.

• Generates SPINscript code

.87 rev/s .12 rev/s .25 rev/s-.06 rev/s -.32 rev/s -.46 rev/s

42˚

43˚ 78˚

-112˚

-95˚

-186˚

Simulating time and movement

• Simulation time marches forward by the Interpreter calling wait(milliseconds)

• Simulator disc positions/angles updated

• waitUntil(cond) is “syntactic sugar”

while (!cond) {

wait(1);

}

Concurrency (1)

• Double-pipe operator | |

• Each parallel branch executes until completion or a wait/waitUntil statement is reached

setSpeed(1,5,1000)

waitUntil(cond1)

setSpeed(2,-5,1000)

setSpeed(3,10,1000)

wait(5000)

||

paused

branch 1 branch 3

pausedbranch 2

donewait(1)

paused paused

Concurrency (2)

• Artist can treat discs independently

• Disc behavior can now be easily defined by non-linear functions

{ while(abs(getPosition(2)-getPosition(1))>=5) { setSpeed(1, sin(getTime())*10, 1000); wait(1); }} || { while(abs(getPosition(2)-getPosition(1))>=5) { setSpeed(2, cos(getTime())*10, 1000); wait(1); }}

3434, 1-speed 40.0 1000.0;3435, wait 1;3435, 2-speed 50.0 1000.0;3436, wait 1;3436, 1-speed 60.0 1000.0;3437, wait 1;3437, 2-speed 0.0 1000.0;3438, wait 1;3438, 1-speed 10.0 1000.0;3439, wait 1;3439, 2-speed 20.0 1000.0;3440, wait 1;3440, 1-speed 30.0 1000.0;3441, wait 1;3441, 2-speed 40.0 1000.0;3442, wait 1;…

sin1_cos2.spinner (INPUT) sin1_cos2.spin (OUTPUT)

Testing Techniques• Lexer/Parser Testing

– Hand compile Spinner to AST, compare with Parser’s AST• Semantic Analyzer testing

– Write compiler breaking/accepting code.• Interpreter Testing

– Write SPINNER for all valid expression types• Simulator testing

– Test all built-in functions• End to End testing

– Write Spinner code, hand compile to SPINscript– Reverse engineer SPINscript to Spinner and compare

• Have mechanisms for jUnit style “instant” regression verification.

Testing Details

• Sample Spinner programs: correctLRM.spinner, incorrectLRM.spinner, testAllBuiltIn.spinner, testConcurrency.spinner, etc…

• Around 120 tests exercising language.//test number 1001 = createDiscs and Get Discs size

createDiscs(6);

wait(1001);

if (getDiscsSize()=6) then { //pass

setGain(1,1);

} else { //fail

setGain(1,0);

}

Lessons Learned• Spend more time in language design.• Think about testing/debugging in language design. • Tackle key language features as early as possible.

Save easy stuff for later.• Have unit tests for difficult key systems before you

code them.• Communication tools are great: cvs, twiki, etc.• Meet more than once a week.• Be sure you have access to target environment for

reverse engineering.• Make sure target is well specified and understood.

Areas for improvement

• Interpreter algorithm is quite slow– Still faster than doing coordinates manually

• Interaction with SPIN not seamless– Moving files around– Debugging visual output slow

• Simulator accuracy of target system– Forced SPIN to take on SPINNER simulator

limitations rather than vice versa

Future Work

• Programming interfaces– Direct manipulation?– A Musical “score”? (Macromedia Director-

esque)

• Concurrency modeling variations

• Simulation optimization– Smart linear solver?

Thanks to our “TA”

Questions?