Ruby under a Microscope

Transcript

1. Ruby Under a Microscope Runtime Revolution November 2014
2. ๏ 1. Motivation ๏ 2. The journey before the runtime ๏ 3. YARV ( The Ruby VM ) ๏ 4. Objects, Classes ๏ 5. Ruby GC ๏ 6, 7. Other Ruby Implementations ( JRuby and Rbx ) ๏ 8..Float::INFINITY ( The Future of Ruby ) Outline
3. 1. Motivation
4. How it’s made!
5. – Mindstorms: Children, Computers, Seymour Papert “A programming language is like a natural, human language in that it favours certain metaphors, images, and ways of thinking”
6. ๏ ShermansTravel - TS Memory Leak ๏ ASW - Concept Mismatch between ancestors, includes and extends ๏ FollowAnalytics - C Extensions Real World Examples
7. 2. The Journey before the runtime
8. How many transformations are performed before running your code?
9. Ruby Tokens AST Nodes C Interpret Machine Lang. Ruby 1.8.x
10. Ruby Tokens AST Nodes YARV Iseq. C Interpret Machine Lang. Ruby 1.9.x
11. Ruby Tokens AST Nodes YARV Iseq. Windows Platform Unix Platform
12. 3. The runtime explained (MRI VM)
13. YARV - Yet Another Ruby VM
14. YARV ๏ Young! ( but it’s changing quickly ) ๏ For internal use! ๏ Stack Based VM ๏ Direct Threading Interpretation
15. YARV’s Basic Registers ๏ Program Counter ๏ Stack Pointer ๏ Current Frame Pointer ๏ Environment Pointer
16. 2 5 self Stack Based frame_t pc | sp | self SP PC
17. control_frame_t PC self type CFP control_frame_t [block] control_frame_t [eval]
18. ๏ Local Access ๏ Dynamic Access ๏ Special Variables ($&, $*, $!, $$) ๏ Catch Tables ๏ Ruby Method Types
19. Direct Threading Ruby Code YARV xxx
20. VM Purpose ๏ Peephole Optimisations • Reduce Instructions Number ๏ Macro Instructions • Operand Unification • Instruction Unification ๏ Stack Caching • n-level stack caching • Branch Prediction
21. Impact
22. 4. Classes & Modules
40. Back to extend and include now…
41. Difference results in where extend is called!
44. Summary ๏ Method Dispatch uses the same algorithm with no exceptions! ( Class, Module, Object ) ๏ Every Ruby Object is a combination of a class pointer and an array of instance variables ๏ A Ruby Class is a Ruby Object that contains method definitions, attribute names, a superclass pointer and a constants Table. ๏ A Ruby Module is a Ruby Object that also contains method definitions, a superclass pointer, and a constants Table.
45. 5. Ruby G.C
46. Ruby 1.9.x and 2.0.x GC ๏ Algorithm: Mark and Sweep
47. Ruby 2.0.x Upgrade!
48. Ruby > 2.0.x ! Generational GC: ! Generational hypothesis: Most Objects die young! Nursery ( Younger ) College ( Older )
49. world[volcano.id] = volcano Old Gen. New Obj.
50. Nursery Old Gen.
51. Nursery Old Gen. Remembered Set Visited every Minor GC
52. Ruby C Extensions Ruby isn’t aware when this happen
53. ๏ Ruby splits objects into 2 groups: • Sunny Objects ( truthful ) • Shady Objects ( untruthful )
54. 6. JRuby
55. ๏ Ruby for the JVM and JVM for the Ruby ๏ Started in 2001 ๏ Usually the fastest Ruby Implementation ๏ Sponsors: Sun, Engine Yard and Red Hat
56. Ruby Tokens AST Nodes Java ByteCode Machine Lang. JRuby Pipeline
57. Mixed-Mode ๏ JRuby has both interpreter and JIT ๏ Cost of generating JVM byte code is high ๏ Interpreter runs faster than JVM’s ๏ JRuby before 9000 translates AST nodes to bytecode. ๏ JRuby 9000 has a new IR ๏ New IR is more suited for implementation of traditional compiler optimisations
60. New IR AST
61. 7. Rubinius
62. – Unknown … ^^ “The most Inceptionist Implementation.”
63. Rubinius consists of two major components: Kernel VM Byte Code Execution Garbage Collection JIT … String Definition Hash Definition Array Definition … C++ Ruby
64. Rubinius Pipeline v.1 Ruby Tokens AST Nodes Rbx Instruc. LLVM Instruc. Machine Lang.
65. Rubinius Pipeline v.2 Ruby Tokens LLVM Instruc. Machine Lang. AST Nodes Rbx Instruc.
66. Examples from integer.rb
67. Examples from Array Definition
68. “The Rubinius Kernel provides window into Ruby internals.”
69. Thank you! … but not yet finished!
70. 8. (“ruby”).succ => “rubz”
71. ๏ Ruby Design Process ๏ Ruby Spec ( consistency between impls ) ๏ Concurrency! When and how? ๏ Fragmentation Risk? ๏ Internal Tools, Debugging API and IDE Support? ๏ Let’s kill the GIL? Is that even possible? The future of Ruby as a Lang.