Rubinius - Tales from the trenches @ Baruco 2012

Transcript

1. Rubinius Tales from the trenches
2. Dirkjan Bussink @dbussink
4. Huh?
5. Class.stub!(:new).and_return(MyClass)
6. Beyond imagination
9. Liskov Substitution Principle
10. class SomeList < Array def push(value) value = Proxy.new(value) if value.is_a?(String) ... end end alias_method :<<, :push end Unmarshal uses Array#<<
11. StackError
13. class PropertySet < Array alias_method :superclass_slice, :[]= private :superclass_slice def []=(name, property) self << property end def <<(property) found = named?(property.name) add_property(property) if found superclass_slice(index(property), property) else super end end end WUT? Ugh Oh, let’s change the meaning!
14. class PropertySet def []=(name, property) add_property(property) end def <<(property) add_property(property) end def add_property(property) clear_cache @order << property unless @order.include?(@property) @properties[property.name] = property end end
15. IDIOT
16. GCC...
17. vm/builtin/regexp.cpp:312: warning: control may reach end of non-void function
19. GCC is fucking stupid. Avoid inane gcc type punning warning Work around GCC's broken strict aliasing checks. gcc 4.2.1 on freebsd 9 wants a newline at the end Make the gcc gods happy Make the stupid compiler gods happy Appease GCC 4.3
20. Ruby is weird
21. class MyClass def to_ary puts "we're here" [1] end end def my_method arg yield arg end my_method(MyClass.new) do |*arg| p arg end we're here [#<MyClass:0xX>] we're here [1] we're here [[1]] [#<MyClass:0xX>] A B C D Call to_ary and ignore
22. can't define singleton method "method" for Float obj = 2.0 def obj.method puts "method on float instance" end obj.method No singleton methods on Numeric
23. class Numeric def singleton_method_added(name) end end obj = 2.0 def obj.method puts "method on float instance" end obj.method method on float instance Singleton method on a Numeric!
24. 3 4 5 6 Becomes true on first condition, false on second 10.times do |i| if (i == 3) .. (i == 6) puts i end end
25. Ruby’s C-API
26. There is no C-API just internals of MRI that people use
27. VALUE rb_data_object_alloc(VALUE klass, void *datap, RUBY_DATA_FUNC dmark, RUBY_DATA_FUNC dfree) { NEWOBJ(data, struct RData); if (klass) Check_Type(klass, T_CLASS); OBJSETUP(data, klass, T_DATA); data->data = datap; data->dfree = dfree; data->dmark = dmark; return (VALUE)data; } MRI internals
28. NotImplementedError: method `class' called on terminated object (0xXXXXXXXX) Inspect object created with rb_data_object_alloc
30. GC can be hard
31. C Stack Object* Object* Heap 1 Object Object Heap 2 Object Object GC moves objects
33. Old Young String Array Object String String Hash
35. Concurrency is tricky
36. Out of order execution
37. a = 0 b = 0 c = 0 d = 0 Core 1 Core 2 a = 1 c = 1 b = 2 d = 2 Statements can be executed in different order
38. addr = Address.new addr.street = "Somestreet" addr.number = 1 shared_addr = addr shared_addr => nil shared_addr => #<Address:0x1c @street="Somestreet" @number=1> shared_addr => #<Address:0x1c> shared_addr => #<Address:0x1c @street="Somestreet"> shared_addr => #<Address:0x1c @number=1> shared_addr = addr executed before other assignments
39. addr = Address.new addr.street = "Somestreet" addr.number = 1 Rubinius.memory_barrier shared_addr = addr
40. Try your code We secretly love weird stuff