Core Unleashed Part II: Introduction to GobiesVM (and STM) @ RubyKaigi 2014

http://blog.brucehsu.org/posts/2014/09/29/rubykaigi-2014-cores-unleashed-part-ii-introduction-to-gobiesvm-and-software-transactional-memory

Transcript

1. Cores Unleashed Part II Introducing GobiesVM (and STM) Szu-Kai Hsu (@brucehsu)
2. Szu-Kai Hsu @brucehsu
5. Previously on Cores Unleashed
6. Concurrency/Parallelism in Ruby Concurrency Parallelism MRI/CRuby ✔ ✘ Rubinius ✔ ✔ JRuby ✔ ✔ Topaz ✘ ✘
7. CPU Usage
8. CPU Usage - MRI
9. CPU Usage - Rubinius
10. CPU Usage - JRuby
11. Thread Safety
12. Thread Safety - MRI
13. Thread Safety - Rubinius
14. Thread Safety - JRuby
15. Locks are bad “Beautiful Concurrency”, Simon Peyton Jones (2007) Taking too few locks Taking too many locks Taking the wrong locks Taking locks in the wrong order Error recovery Lost wake-ups and erroneous retries
16. Software Transactional Memory
17. GobiesVM https://github.com/brucehsu/GobiesVM
18. GobiesVM in a nutshell Written in Go, utilizing native data structures and GC A Ruby subset derived from tinyrb Therefore uses a LEG parser instead of bison Stack-based VM which resembles YARV Minimal modification to existing code
19. VM Coroutine Coroutine Coroutine Coroutine Bytecode Abstract Syntax Tree
20. VM Coroutine Coroutine Coroutine Coroutine Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction Transaction
21. BC_GETLOCAL, i BC_SEND, +, 1 BC_PUTOBJ, 1 BC_SEND BC_GETLOCAL Begin End Transaction bytecode stack ivar object-set rev
22. Transactional Locking II Global Timestamp Transaction Transaction Local Timestamp Local Timestamp Read Set Read Set Write Set Write Set Transaction Local Timestamp Read Set Write Set
23. Speculative Execution (READ) a Read Set Write Set a b c d e 0x5566 0x5567 0x5568 0x5569 0x5570 0x5566 10
24. Speculative Execution (WRITE) a+=1 Read Set Write Set a b c d e 0x5566 0x5567 0x5568 0x5569 0x5570 0x5566 a 11 10 0x5566
25. Speculative Execution (READ-AFTER-WRITE) a Read Set Write Set a b c d e 0x5566 0x5567 0x5568 0x5569 0x5570 0x5566 a 11
26. Combined Object-Set RObject Object-Set Read-Set
27. Combined Object-Set RObject Object-Set RObject Write-Set
28. Validation Read Set Write Set Global Timestamp Check rev of object rev > local_timestamp: object has been modified Acquire locks of objects to be modified Abort on failure Increments by one
29. Commit RObject class ivar methods RObject class ivar methods Copy to original
30. – Torvalds, Linus (2000-08-25) Talk is cheap. Show me the code
31. Live Demo
32. What’s next?
33. Better parser Go provides goyacc for parsing But we have to do lexical scanning ourselves. https://sourcegraph.com/blog/multi-language-lexer- and-scanner-for-go
34. Better syntax support What we don’t have now: Conditional statements Class/Method definitions Double-quoted strings And more…
35. Atomic operations New syntax: atomic block Make every statement atomic
36. Production-ready (perhaps) Rubygems Native extension interface Go can work with C code, but not thread-safe Comprehensive exceptions
37. Optimizations Performance! Performance!! Transaction length
38. GobiesVM https://github.com/brucehsu/GobiesVM
39. Thanks for your attention Any questions?