Leaky procs

leaky.rb

class Printer
  @messages = []

  def self.print
    puts yield
  end

  def self.lazy_print(val=nil,&block)
    @messages << val || block
  end

  def self.messages
    @messages
  end

  def self.clear
    @messages = []
  end
end

class Foo 
  def initialize(i)
    Printer.print { "hey #{i}" }
  end
end

class LeakyFoo 
  def initialize(i)
    Printer.lazy_print -> { "hey #{i}" }
    #Printer.lazy_print String.new("hey #{i}")
  end
end

100.times { |i|  Foo.new i }
100.times { |i|  LeakyFoo.new i }

GC.start # first call, will release all LeakyFoo with Strings on 2.x
puts "Foo count = #{ObjectSpace.each_object(Foo).count}"		
puts "LeakyFoo count = #{ObjectSpace.each_object(LeakyFoo).count}"	

GC.start # this will release all LeakyFoo with Strings on 1.9
puts "LeakyFoo count = #{ObjectSpace.each_object(LeakyFoo).count}"	

# now we want all of them to go away
Printer.clear
GC.start
puts "LeakyFoo count = #{ObjectSpace.each_object(LeakyFoo).count}"