YARV Progress Report

kev — Fri, 14 Oct 2005 22:29:00 -0400

Koichi SASADA

Caution! (review)

I can’t speak English well
- If I say strange English, you can see the slide page ** Or ask another Japanese. They can speak English well.
- If you have any queestions, ask me with: ** Japanese (recommended) ** Ruby, C, Scheme, Java, … ** IRC (#rubyconf on freenode)

Agenda

Self Introduction and Japanese Activities
Overview of YARV
Goal of YARV
Current YARV status
- YARV Design, Optimization Review
- Evaluation
Conclusion

Self Introduction

“SASADA” the family name
“Koichi” is given name -> “ko1”
A Student for Ph.D. 2nd grade (Not a Son-shi)
- Systems Software for Multithreaded Arch ** SMT/CMP or other tech ** i.e.: Hypter threeading (Intel), CMT (Sun), Power (IBM) ** OS, Library, Compiler and Interpreter ** YARV is my first step for parallel interpreter
- Computer Architecture for Next Generation at Public Position
Nihon Ruby no Kai
- Organized by Mr. Takahashi (maki)
“Rubyist Magazine”:http://jp.rubyist.net/magazine
- vol 10 at 10 Oct 2005
- 1st anniversary at 6 Sep 2005 (vol 9)
Ruby-dev summary
English Diary some days
- But retired

Our Activity: Rubyist Magazine

Many Japanese articles related to Ruby
- Cooperate with Ruby Code & Style?
- I’m writing YARV internal named “YARV Maniacs”
Many interviews of Japanese Rubyists

RubyMa!

Published 1 Apr 2005 (April Fools)
- Joke web-zine
Parody of Negima!
Many useful articles
- The Takahashi method: def Takahashi end

Overview of YARV

Overview: Background

Ruby is used world-wide, (one of)? the most comfortable programming languages
Ruby is slow, because interpreter doesn’t use Virtual Machine Technology
We need Ruby VM!
“YARV: Yet Another Ruby VM”:http://www.atdot.net/yarv/
- Started development on 1 Jan 2004 ** At that time, there were some VMS for Ruby
Ruby’s license, of course

Overview: FAQ (review of last year FAQ)

Q: How is “YARV” pronounced?
A: You can pronounce “YARV” what you like.
Q: Should I remember the name “YARV”?
A: No. If YARV succeeds, it gets renamed to Rite, if it doesn’t, no one will remember it
- About YARV, name is NOT ???

Overview: YARV System

Ruby Program –> Compiler –> YARV Instruction Sequence –> ==> Virtual Machine ==> AOT Compiler –> C Source –>

Overview: Current Interpreter

Ruby Program: a = b + c
Syntax tree: (a =) -> (method dispatch + (b), (c))
Current interpreter traverses AST directly

Overview YARV - Stack Machine

The Goal of YARV

YARV: Yet Another RubyVM -> The RubyVM
- To be the Ruby 2.0 VM Rite
Fastest Ruby Interpreter
- Easy to be the current Ruby interpreter

The Goal of YARV (cont.)

Support all Ruby features
- Include Ruby 2.0 new syntaxes
Native thread support
- Concurrent execution (Giant VM lock)
- Parallel execution on parallel machine
Multi-VM instance
- Same as Mutlti-VM in Java

Goal: Ruby 2.0 syntax

Matz will decide it :-)
”{|…| …}” == “->(…){ … }”
- “I think this is ugly” – Ko1
Multiple-values
- Same as Array? Or first class multiple-values support?
Selector-namespace?

Goal: Native Thread Support

Three different thread models
Model 1: User-level thread (green)
- same as current Rubt interpreter
Model 2: Native thread with giant VM lock
- Same as current Ruby interpreter
- Easy to implement
Model 3: Native-thread with fine grain lock
- Run ruby threads in parallel
- For enterprise?

Goal: Native Thread Support (cont.)

h5. Current Ruby Interpreter & Model 1

CPU1: Thread 1 -> Thread 2 -> Thread 1
CPU2: Idle……..

h5. Model 2: Native thread with Giant VM Lock

CPU1: Thread 1 -> (Lock) -> (in OS thread 2) Thread 2 -> (Lock) -> Thread 1
CPU2: Idle……..

On this system, other threads can run (but the Ruby threads switch cpus with a lock)

h5. Model 3: Native thread with Fine Grain Lock

CPU1: Thread 1……
CPU2: Thread 2……

Goal: Native Thread Support Summary

Goal: Multi-VM Instance

Current Ruby process: ( Process ( Ruby Interpreter (VM) ) )
Ruby Process with Multi-VM Instance ( Process ((many) Ruby Interpreter (VM) ) )
Current Ruby can hold only 1 interpreter in 1 process
- Interpreter structure causes this problem
- Using many global variables
Multiple-VM instance
- Running some VM in 1 process
- It will help ruby embedded apps ** mod_ruby, etc.

Multi-VM Instance + Thread Model 2

CPU1: Thread 1 -> (Lock of VM1) -> Thread 2 -> Lock of VM1

Goal: Load Map

All Ruby features support
- Feb. 2006 … ?
Native Thread Support
- Experimental: Dec. 2005
- Complete: 2006?(model 2) 2007?(model 3)
Multi-VM support
- Experimental Feb 2006
- Complete: 2006?

Current Status of YARV

Status: System

Some almosts, an incomplete and a not yet

Status: Supported Ruby Features

Almost all Ruby features
Not supported:
- Few syntaxes … {|*arg| …}
- Visibility
- Safe level ($SAFE)
- Some methods written in C for current Ruby implementation
- Around Signal
- C extension libraries ** (Because YARV can’t run mkmf.rb)

Status: Versions

0.2 YARV as C Extension
- Need a patch to Ruby interpeter
0.3 (2005-8): YARV as Ruby Interpreter
- merged to Ruby source (1.9 HEAD)
- Maintained on my subversion repository
Latest version: 0.2
- Native thread (pthread / Win32) supports model 2

YARV 0.2.x

(Ruby Interpreter (Evaluator)) -> YARV (Compiler, VM, Optimizer) -> back

YARV 0.3.x

YARV marged with Ruby Interpreter
Future work
- Generational GC
- m17n
- …

“Status: Compile & Disasm CGI”:http://www.atdot.net/yc/

Status: VM Design

5 registers
- PC: Program Counter
- SP: Stack Pointer
- CFP: Controler Frame Pointer
- LFP: LOcal frame pointer
- DFP: Dynamic Frame Pointer
Some stack frame
Control stack and value stack

Status: Optimization

Simple Stack Virtual Machine
- Re-design Exception handling
Peep-hole optimization on compile time
- I gave up static program analysis
- Dynamicity is your friend but my ENEMY!
Direct Threaded code with GCC
Specialized Instruction
- i.e. Ruby program “x+y” compiled to special instruction instead of a method dispatch instruction
In-line Cache
- In-line Method Cache
- In-line constant value cache ** Because ruby’s “constant variable” is not constant!
Embed values in an instruction sequence
Unified Instruction
- Operands Unification
- *InsnA x -> InsnA_x
Unified instructions are auto generated by VM gen
- I only decide which instructions should be combined
Stack Caching
JIT Compilation
- I made easy one for x86, but…
- Too hard to do alone. I retired.
AOT Compilation
- YARV bytecode -> C Source
- Easy to develop
- Hard to support exception

Status: Demo

YARV building demo?
YARV running demo?

Status: Evaluation

Yield block is not fast (2-3 times faster than C Ruby) - optimizing this will be work for the future
With all optimizations, basic math can see a 50 times performance gain over C Ruby
Ackermann can see 20 times gain over C Ruby
Wow - YARV as it stands stacks up really well against other interpreters for basic math type stuff

Status: Awards

2004: Funded by IPA Exploratory Software Development “Youth”
- IPA: Information-technology Promotion Agency, Japan
2005: Funded by IPA Exploratory Software Development (continuance)
2004: got awarded “Super creator” from IPA

Conclusion

YARV supports almost all Ruby syntax
YARV suppoorts some RUby libraries
YARV 0.3.2 supports native thread
YARV achieves significant speedup for ruby programs which have VM bottleneck
- This means that we can enjoy Symbol programming with Ruby

Conclusion: Future Work

Support all Ruby features
- mkmf.rb
Support every thread model
- especially 2 and 3
Support multi-VM Instance

How Can You Help me

Any comments are welcome
- Build reports, Bug reports, architecture reports, …
yarv-devel Mailing List
- English ML for YARV development ** Matz and other Japanese join
“YARV Wiki”:http://yarv.rubyforge.org/pukiwki/pukiwiki.php
Give me a job! (I’ll finish my course 2 years later)

Special Thanks

Matz the architect of Ruby
IPA: His sponsor
YARV development ML subs
All rubyists

Q&A

All: We want the demo!
- ko1: OK
Derek Sivers: A bunch of Japanese :-)
- ko1: Some more Japanese

"YARV Progress Report" by Pawel

Sat, 15 Oct 2005 01:01:06 -0400

Derek said something to the effect of ‘Your English was very good. Good job!’

Sasada-san just replied to thank him.

Gluttonous: YARV Progress Report