Question

With Ruby 1.8.7 I am trying to extend Thread class here is snippet

class Foo < Thread
  attr_accessor :bar
end

t = Foo.new do 
  puts "Foo thread begins"
  self.bar = "Bar value" # also tried @bar
  sleep(2)
  puts "Foo thread ends"
end

puts "Value: #{t.bar}"
sleep(10)
puts "Value: #{t.bar}"

Output is

>Foo thread begins
>Value: 
>Foo thread ends
>Value:

Why am I not able to see :bar attribute for Foo class? Since this is probably not made to work this way, how do I pass value from my newly created Thread to main thread?

Thank you

Answer 1

self in your thread refers to the main object, not t. Since the method bar= is not defined on the main object, it throws an error, which is not sent to the main thread.

There are several ways you can access the thread:

1) Foo.new{p Foo.current}

2) Foo.new{|foo| p foo}

3) foo = Foo.new{p foo}