From: Alex Young <alex@...>
Date: 2006-12-07T19:13:10+09:00
Subject: NoMethodError in protocol.rb

Does this look familiar to anyone?

NoMethodError: undefined method `+' for nil:NilClass at 
/usr/local/lib/ruby/1.8/net/protocol.rb:176:in `write0'

I'm getting it sporadically during some fairly heavy XMLRPC traffic.  It 
doesn't make very much sense to me, because write0 looks like this:

def write0(str)
   @debug_output << str.dump if @debug_output
   len = @io.write(str)
   @written_bytes += len  # <= line 176
   len
end

The error must mean that @written_bytes is nil.  It's only called from 
within a block passed to writing, which looks like this:

def writing
   @written_bytes = 0
   @debug_output << '<- ' if @debug_output
   yield
   @debug_output << "\n" if @debug_output
   bytes = @written_bytes
   @written_bytes = nil
   bytes
end

Is this a known thread-safety issue with a known solution, or would a 
patch be in order?  I've been testing this on 1.8.4, because that's what 
we've got in production.  Does anyone know if it's been addressed in 1.8.5?

Thanks,
-- 
Alex