From: Gary Wright <gwtmp01@...>
Date: 2007-11-07T05:23:46+09:00
Subject: Re: Changing date backward messes up threaded sleep


On Nov 6, 2007, at 9:44 AM, Robert Williams wrote:
> Bump...I also need this resolved.
>
> This also occurs with select having a timeout...which I believe is
> ruby's definition of sleep anyway.
>

What do you mean by 'also'?  Your first posting was
about a timeout with select.

Ruby's sleep actually is a request to the thread scheduler to
stop the current thread until the system clock has reached
(now + delay).  So if you move the clock backwards, it will take
that much longer to reach (now + delay).  If you move the clock
forwards then the thread becomes runnable immediately.

This might also explain why your C version works since it is
probably calling the sleep/nanosleep system call rather than
communicating with some process based/green thread scheduler.

Gary Wright