From: m_seki@...
Date: 2003-01-12T15:40:33+09:00
Subject: Re: drb bug?


Hi,

> > for example ... # sorry, it is untested.
> > 
> > block = Proc.new { |val| puts val }
> > (0..9).each do |i|
> >   server.register(100*i + 1, &block)
> > end
> > 
> 
> Same problem, after this change.
> 
> But you are right about GC being involved. GC.disable in the client 
> prevents the problem from happening. So something else is getting 
> collected. (Is it possible that the proc is copied internally?)

oops. it is drb's problem. I have noticed this behavior just now.

 blk = Proc.new { |x| }
 p blk.__id__    # -> 537833186
 p blk           # -> #<Proc:0x401d5dd8>
 
 def foo(b0, &b)
   p [b0.__id__, b0]
   p [b.__id__, b]
 end

 foo(blk, &blk)  # -> [537833186, #<Proc:0x401d5dd8>]
                 # -> [537966706, #<Proc:0x401d5dd8>]



In drb, The given block cannot be used after a method is returned.
You can avoid a problem if using the Proc object instead of giving block.

--- server.rb
...
class Server
   ...
   def register(value, action)   ## not &action
     @observers << [value, action]
   end
   ...
end
...

--- client.rb
...
block = Proc.new { |val|
  puts val
}
(0..9).each do |i|
  server.register(100*i + 1, block) ## not &block
end
...




Or, use DRb::TimerIdConv.
--- client.rb
require 'drb'
require 'drb/timeridconv'
DRb.install_id_conv(DRb::TimerIdConv.new)

DRb.start_service()
server = DRbObject.new(nil, 'druby://localhost:9500')

block = Proc.new { |val|
  puts val
}
(0..9).each do |i|
  server.register(100*i + 1, &block)
end

sleep