From: Pat Mahoney <pat@...>
Date: 2003-01-03T13:33:13+09:00
Subject: Re: sysread of /dev/video with threads

On Thu, Jan 02, 2003 at 12:13:03PM +0900, Yukihiro Matsumoto wrote:
> Hmm, probably select(2) does not show "ready" for /dev/video0 for your
> system.  Could you try
> 
>   ruby -e 'p IO.select([File.open("/dev/video0")])'
> 

I fiddled around with the gqcam source code, and added a select(2) call
just before the read(2) call which reads a frame of video.  Here too,
select(2) never reports "ready" yet read(2) works fine, so I assume it
is the correct behavior.  According to the manpage, select(2) does not
return when one can read from the file descriptor, but when one can read
from the file without blocking...  (I must admit, this means little to
me)

I assume it is the ruby threads which introduce a select call?

Well, thanks for all the help.  It seems I need to learn a bit more
before I can think about solving the problem.

-- 
Pat Mahoney	<pat@tinyleaf.org>