From: Robert Klemme <shortcutter@...>
Date: 2006-11-05T19:55:15+09:00
Subject: Re: trap and multiple occurences

On 05.11.2006 02:59, Gabriele Marrone wrote:
> A very good practice is writing signal handlers that just set a global 
> variable with the signal(s) received, and then check that variable and 
> actually do something from within the application main loop.
> There are many good reasons, some are here: 
> http://www-128.ibm.com/developerworks/linux/library/l-reent.html
> (In fact I just googled for a link that explains what I'm thinking, I'm 
> lazy and sleepy so I didn't read throughly that page and I hope it 
> really says what I mean :P)

The way I'd probably do it is to set up a Queue and have a reader thread 
that will process signals placed into the queue.  Something along the 
lines like this

require 'thread'

SIG_HANDLER = Queue.new

Thread.new do
   while ( sig = SIG_HANDLER.deq )
     print "SIGNAL: ", sig.inspect, "\n"
   end
end

Signal.list.each do |name, sig|
   Signal.trap sig do |s|
     SIG_HANDLER.enq s
   end
end

20.times do
   puts "."
   sleep 1
end


Kind regards

	robert