playing with cloby

example.rb

require 'rubygems'
require 'cloby'

Ref = Java::clojure.lang.Ref

class Foo < Clojure::Object
  attr_accessor :count

  def initialize(count = 1)
    @count = count
  end

  def to_s
    "[Foo #{count}]"
  end
end

class Bar
  SIZE = 5

  def initialize
    @cells = Array.new(SIZE) { Ref.new(rand(10)) }
  end

  def get(i)
    @cells[i].deref
  end

  def set(i, value)
    @cells[i].set(value)
  end

  def inspect
    result = "[Bar "
    SIZE.times do |i|
      result += "#{get(i)} "
    end
    result + "]"
  end
end

sample irb session

jruby-1.6.6 :001 > require 'example'
 => true 
jruby-1.6.6 :002 > foo = dosync { Foo.new }
 => [Foo 1] 
jruby-1.6.6 :003 > foo.count
 => 1 
jruby-1.6.6 :004 > dosync { foo.count = 3 }
 => 3 
jruby-1.6.6 :005 > bar = dosync { Bar.new }
 => [Bar 9 6 3 5 4 ] 
jruby-1.6.6 :006 > bar.get(0)
 => 9 
jruby-1.6.6 :007 > dosync { bar.set(0, 'x') }
 => "x" 
jruby-1.6.6 :008 > bar
 => [Bar x 6 3 5 4 ]
jruby-1.6.6 :009 > dosync { bar.set(2, foo) }
ConcurrencyError: No message available
  from org/jruby/clojure/ClojureLibrary.java:73:in `dosync'
  from (irb):9:in `evaluate'
  from org/jruby/RubyKernel.java:1077:in `eval'
  from /Users/tim/.rvm/rubies/jruby-1.6.6/lib/ruby/1.8/irb.rb:158:in `eval_input'
  from /Users/tim/.rvm/rubies/jruby-1.6.6/lib/ruby/1.8/irb.rb:271:in `signal_status'
  from /Users/tim/.rvm/rubies/jruby-1.6.6/lib/ruby/1.8/irb.rb:155:in `eval_input'
  from org/jruby/RubyKernel.java:1408:in `loop'
  from org/jruby/RubyKernel.java:1181:in `catch'
  from /Users/tim/.rvm/rubies/jruby-1.6.6/lib/ruby/1.8/irb.rb:154:in `eval_input'
  from /Users/tim/.rvm/rubies/jruby-1.6.6/lib/ruby/1.8/irb.rb:71:in `start'
  from org/jruby/RubyKernel.java:1181:in `catch'
  from /Users/tim/.rvm/rubies/jruby-1.6.6/lib/ruby/1.8/irb.rb:70:in `start'
  from /Users/tim/.rvm/rubies/jruby-1.6.6/bin/irb:17:in `(root)'
jruby-1.6.6 :010 >