The 2nd day of RubyKaigi 2009 (Afternoon)

In this afternoon, I attended these sessions:

• Community Appeals
  
  • Not only Japanese regional communities
  • But also community from Shanghai(China)
• Keynote Address by Matz
  
  • speaker: Matz
  • Theme: compass for us(rubyists)
  • Now is the golden age for programmings
  • Lisp is awesome, but there was no good time
  • Ruby was also too for a time, but now, here are many rubyists
  • Things we should remember
    
    • Attitude
    • NO "Sour Grapes"
    • Fix broken windows(broken window theory)
    • Responsibility
  • We make our communty fairness, for example...
    
    • I don't hope "That Matz says is the correctness."
    • I hope "Hi Matz, you again committed with bugs yet, our community suggest to revoke your commit right."
  • Introducing Matz' local environment for writing and commiting ruby
    
    • Emacs
    • Subversion
    • Stacked GIT(written in Python)
  • Introducing not-yet-open Ruby functions from Matz' local environment e.g. Complex literal  2 + 4i
• Lightning Talks
  
  • Monitoring solar power inverter by RoR
  • ActiveLDAP
  • and many other LTs
• NeverBlock and I/O Concurrency in Ruby
  
  • speakers: Mohammad A. Ali and Ehab El-Badry
  • NeverbBock is a library based on Fiber
  • Pros and Cons of concurrency
    
    • Using blocking I/O
      
      • Pros: not take into account of synchronization
      • Cons: too much latency
    • Using multi process
      
      • Pros: not take into account of synchronization, scaling on multi CPU
      • Cons: difficult to share resources, latency with inter-process communication
    • Using multi thread
      
      • Pros: speed of thread construction is fast, speed of inter-thread communication is fast
      • Cons: synchronization needs tricky techniques, risk of dead lock
    • Using reactor pattern
      
      • Pros: much more speed, much more scaling
      • Cons: if one of all is blocked, all are blocked, risk of dead lock
    • Using Ruby 1.9 Fiber
      
      • Pros: very faster, less memory footprints
      • Cons: ugly implementation, risk of stack overflow if you call recursively
  • NeverbBock code sample
    
    • NB::Reactor.new { #codes }
    • NB::Fiber.new { #codes }
  • Writing like blocking I/O
  • Ease to write multi-thread programming
  • But many memory footprints
  • supporting libraries
    
    • Net/Http
    • ActiveRecord
    • ActiveResource
    • Thin
    • (expected)Passenger
    • (expected)Sequel
• JRuby Update 2009
  
  • speakers: Thomas Enebo and Nick Sieger
  • JRuby is Ruby 1.8.6 compatible
  • If you append --1.9 option, JRuby becomes Ruby 1.9.1 compatible
  • Why we use JRuby
    
    • Java codes are anywhere
    • JVM's GC and HotSpot are great
    • Java handles native thread
    • Java uses all cores/processors
    • Improvement of code base is keeping on continuously
  • Demo
    
    • include Java interface as Ruby module
    • write concrete implementation of Java abstract method as Ruby instance-specific method
  • Cannot use extended C libraries
    
    • We re-write popular libraries with Java
    • Rest of these will be re-writed by Java or FFI
  • JRuby 1.3.1 were released on 2009/06/15
    
    • support GAE/J
    • support 1.9 mode on jirb
  • JRuby 1.4.0 is scheduled in 2009/09
    
    • JSR-292 support
    • more integration with Java
    • more communication with other LL on JVM
  • ruby2java can convert from Java class to Ruby class
  • Frameworks and sites using JRuby
    
    • monkeybars
    • GitHub:FI
    • JrME
    • Kenai.com

N.B. These summaries may be imprecise.

The most impressive in this afternoon is that I have heard "GitHub:FI" at JRuby session, that's first for me.

After the last session in this day, Beer bust was held.