From: "Jean G." <rubynewbee@...>
Date: 2010-03-12T12:01:58+09:00
Subject: Is ruby-1.9 threads data safer?

Hello,

$ cat count_threads.rb
class Counter
  attr_reader :count
  def initialize
    @count = 0
  end
  def tick
    @count += 1
  end
end

c = Counter.new
t1 = Thread.new { 10000.times { c.tick } }
t2 = Thread.new { 10000.times { c.tick } }
t1.join
t2.join
puts c.count

$ ruby count_threads.rb
20000
$ ruby count_threads.rb
20000
$ ruby count_threads.rb
20000



My ruby version is 1.9, running under Linux-2.6.31 kernel.
For the code above, though we know the @count isn't safe for sharing.
But the result is always correct.
So can we say ruby-1.9 behaves better on threads than 1.8?

Thanks.