From: Tanaka Akira <akr@...17n.org>
Date: 2005-08-10T15:25:06+09:00
Subject: Re: event driven framework for ruby

In article <42F996FE.3000702@path.berkeley.edu>,
  Joel VanderWerf <vjoel@path.berkeley.edu> writes:

> That post (148436) suggests that the native thread running the
> interpreter is not blocked, and the only danger of blocking is in the
> *ruby* thread reading the socket. Is that right? A bad UDP packet won't
> stop other ruby threads?

Ruby threads is not native threads.
In [ruby-talk:148436], the entire process is not blocked because
O_NONBLOCK is used.

> I tried to hang ruby with
>
>   hping2 --udp -p 9999 -b
>
> but the socket did not block.

I can see the entire process blocking with following script.

server% uname -a
Linux nute 2.6.8-2-686 #1 Thu May 19 17:53:30 JST 2005 i686 GNU/Linux
server% ./ruby -rsocket -e '
Thread.new { 1000.times {|i| p i; sleep 1 } }
u = UDPSocket.new; u.bind("0.0.0.0", 2000)
p u.recv(100)'

client% hping2 --udp --count 1 --badcksum --destport 2000 server
-- 
Tanaka Akira