Threads terminating

ruby-talk
1

Why this simple program give no output, and terminates immidiatly
after its launched? There should be thread running and giving lots of
'lala', am I right?
class Bar
  def initialize

  end
  def foo
     Thread.new do
      while true
        puts "lala\n"
      end
    end
  end
end

b=Bar.new
b.foo

2

Why this simple program give no output, and terminates immidiatly
after its launched? There should be thread running and giving lots of
'lala', am I right?
class Bar
def initialize

end
def foo
    Thread.new do

try changing this to a = Thread.new

     while true
       puts "lala\n"
     end
   end

then add an a.join here

end
end

b=Bar.new
b.foo

Someone else would have to explain why that happens. Don't know enough about threads (let alone ruby's) to explain that.

···

On 20 Oct, 2009, at 1:05 AM, pawel wrote:

--
patrick

3

When you create a thread, the main threads continues. In you case the main
thread terminates after calling "Thread.new" so the program exists.

If you want to *wait* all the created threads to finish their work, then you
must "join" them:

  my_thread = Thread.new do .... end
  do other stuff in main thread
  my_thread.join

···

El Martes, 20 de Octubre de 2009, pawel escribió:

Why this simple program give no output, and terminates immidiatly
after its launched? There should be thread running and giving lots of
'lala', am I right?
class Bar
  def initialize

  end
  def foo
     Thread.new do
      while true
        puts "lala\n"
      end
    end
  end
end

b=Bar.new
b.foo

--
Iñaki Baz Castillo <ibc@aliax.net>

4

pawel wrote:

Why this simple program give no output, and terminates immidiatly
after its launched? There should be thread running and giving lots of
'lala', am I right?
class Bar
  def initialize

  end
  def foo
     Thread.new do
      while true
        puts "lala\n"
      end
    end
  end
end

b=Bar.new
b.foo

Hi Pawel, here is one example, see if you can follow it.

class Bar
   def initialize( msg )
      @msg = msg
   end
   def foo
     t_exit = Time.now.to_i + 3
     while true
       puts @msg
       break if Time.now.to_i > t_exit
       sleep 0.5
     end
   end
end

b1 = Thread.new{ Bar.new("x").foo }
b2 = Thread.new{ Bar.new("o").foo }

# here main thread waits for thread b1 and b2 to exit
b1.join
b2.join

···

--
Kind Regards,
Rajinder Yadav

http://DevMentor.org
Do Good ~ Share Freely

5

All threads other than main are demon threads in Ruby, i.e. as has been explained they do not keep the process alive.

Kind regards

  robert

···

On 20.10.2009 00:34, Patrick Okui wrote:

On 20 Oct, 2009, at 1:05 AM, pawel wrote:

Why this simple program give no output, and terminates immidiatly
after its launched? There should be thread running and giving lots of
'lala', am I right?
class Bar
def initialize

end
def foo
    Thread.new do

try changing this to a = Thread.new

     while true
       puts "lala\n"
     end
   end

then add an a.join here

end
end

b=Bar.new
b.foo

Someone else would have to explain why that happens. Don't know enough about threads (let alone ruby's) to explain that.

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/