From: badcherry <badcherry@...>
Date: 2007-02-21T11:45:08+09:00
Subject: Ruby, Curses, Threading, and Sleeping...

I'm attempting to get a curses application running in a threaded
environment to handle input with no delay.  This is needed for
portability reasons.  I have found though that in a threaded ruby
environment that whenever there is a call to sleep (even in a
different thread) then Curses behaves differently.  The following code
acts as I expect it to:

require 'curses'
require 'pp'

ch = []

Curses::init_screen
Curses::stdscr.nodelay = true

t = Thread.new do
	x = 0
end

while c = Curses::stdscr.getch
	break if c == 9	#tab exits
	sleep 0.1
	Curses::setpos(10,10)
	Curses::addstr("               ")
	Curses::addstr(c.to_s)
	Curses::refresh
	ch << [c]
end

Curses::close_screen
pp ch

It works just fine and grabs input with out waiting for it and returns
an error value when there is no input.  If you change the line 'x = 0'
to 'sleep 1' then the behavior of Curses changes and the line c =
Curses::stdscr.getch will now sit idle until a key has been pressed.

Is there a better way of making threads idle other than sleep that
won't cause this side effect?  Is there a better way of grabbing input
that the way that I am using?

My stats:
Emachines M6805 (running in 32bit)
Ubuntu 6.10
Ruby 1.8.4
----
Barry Dmytro
badcherry@mailc.net
http://badcherry.org/