leaky_singleton_methods.rb

N = 10_000_000

class Foo
  def initialize
    @ary = (0..N).map { Object.new }
  end

  def a
    # this is a closure that has captured self
    define_singleton_method("O_o") {}
  end
end

def wat
  Foo.new.a
end

wat
GC.start

# memory doen't go down!!

# my theory is that the object is captured in the proc,
# then the eigenclass is always "reachable" according to the ruby
# mark and sweep GC because it's in the real class heiarchy,
# so the closed-in self is always "reachable", so the object 
# is never marked

puts "sleeping"
sleep 10