SCG, University of Bern. CHOOSE Talk: "The present and future of Pharo" 14.07.2009

1. The present and
future of Pharo

2. What?
A progressive, open-source Smalltalk platform
for professional use.

3. What?
A flexible environment to support the research
of new language concepts.

4. What?
Pharo = Language + IDE
Pure Object-Oriented Language
Dynamically Typed

5. History
Based on Squeak Smalltalk
+ Major Cleanups (MVC, eToys)
+ New UI Look / TrueType
+ Tools
+ Block Closures
+ Lots of bugfixes and small improvements

6. 699 Bug-reports closed
377 Updates
Release Planned: August 2009

9. Getting
Started
(if needed)

10. Pier

11. Pier

12. Smalltalk with OO-Database
Pharo is the IDE

13. Future

14. ...cleaner

15. ...smaller

16. ...faster

17. (of course)

18. Enable
Evolution

19. Enable
Experiments

20. Examples
- Compiler
- Slots
- JIT and AOStA

21. Old Compiler
- From 1976
- Not OO
- Hard to understand. Hard to change
We need a better Compiler!

22. New Compiler
- Originally by Anthony Hannan
- Based on Visitors
- Reusable and Pluggable Backend (IRBuilder)
- Uses RB AST
- SmaCC Parser
Easier to understand.
Easier to change

23. New Compiler
Scanner Semantic Code
code AST AST Bytecode
/ Parser Analysis Generation
Code generation in detail
Build Bytecode
AST IR Bytecode
IR Generation
ASTTranslator IRTranslator
IRBuilder BytecodeBuilder

24. Plans...
- New BlockClosure Format
- Plugin architecture: Parser, Checker, CodeGen
- Use RB Parser (Faster, Error messages)

25. Examples
- Compiler
- Slots
- JIT and AOStA

26. Instance Vars
- Not objects
- Change behavior?
- Change memory layout?
Instance state should be more
powerful!

27. Slots
- Are objects
- Allow custom subclasses
- Change behavior and memory layout
Without Performance penalty!

28. Auto-Accessor
MopObject subclass: #SlotExample
slots: '{AutoAccessorSlot named: #hello}'
classVariableNames: ''
poolDictionaries: ''
category: 'SlotExamples'
Create accessor-methods at compile-time

29. Active Slot
MopObject subclass: #SlotExample
slots: '{ActiveSlot named: #hello
action: [Beeper beep]}'
classVariableNames: ''
poolDictionaries: ''
category: 'SlotExamples'
Evaluate block on read

30. Sparse Slot
MopObject subclass: #SlotExample
slots: '{SparseSlot named: #a.
SparseSlot named: #b.
SparseSlot named: #c}'
classVariableNames: ''
poolDictionaries: ''
category: 'SlotExamples'
Store values in one Dictionary

31. iVar Slot
MopObject subclass: #SlotExample
slots: '{IVarSlot named: #a}
classVariableNames: ''
poolDictionaries: ''
category: 'SlotExamples'
Normal instance Variable

32. Auto-Accessor
MopObject subclass: #SlotExample
slots: '{AutoAccessorSlot named: #hello}'
classVariableNames: ''
poolDictionaries: ''
category: 'SlotExamples'
Create accessor-methods at compiled-time

33. Slot subclass: #AutoAccessorSlot
instanceVariableNames: ''
....
postCreationAction
self generateGetter.
self generateSetter.
generateGetter
class compile:
(String streamContents: [:stream |stream
nextPutAll: self name; crtab;
nextPutAll: '^', self name asString])

34. Active Slot
MopObject subclass: #SlotExample
slots: '{ActiveSlot named: #hello
action: [Beeper beep]}'
classVariableNames: ''
poolDictionaries: ''
category: 'SlotExamples'
Evaluate block on read

35. Active Slot
AutoAccessorSlot subclass: #ActiveSlot
instanceVariableNames: 'action'
....
emitReadUsing: methodBuilder
methodBuilder
pushLiteral: action;
send: #value.
super emitReadUsing: methodBuilder

36. Status
- First Prototype
- Integration with ClassBuilder
- Compatibility with iVars
- Explore different designs

37. Examples
- Compiler
- Slots
- JIT and AOStA

38. VM
- Virtual Machine uses Interpreter
- JIT Compiler under development (Eliot Miranda)
How to optimize even more?

39. AOStA
- Provide API for accessing runtime data
- PIC: Polymorphic Inline Cache
Record class per send instruction
- Hotness Counter
Where do we spend time?

40. AOStA
PIC
BC 2 SSA 2
BC SSA OPT SSA BC
SSA BC
Optimize SSA-Form
(Static Single Assignment)

41. AOStA
- Use PIC-Data for specialization
- Inline often-called methods
- Special Bytecode for primitive types (Floats)

42. AOStA
- Bytecode-to-Bytecode optimization
- Purely realized in Smaltalk
- Accessible in the image. Reflection?

43. More...
- Improve Tools
- Real Modules
- Reflection
- .......

44. Join Us!
Goal: learning and having fun
http://pharo-project.org