From: Robert Klemme <shortcutter@...>
Date: 2009-11-23T19:02:00+09:00
Subject: Re: issues with Kernel#select

2009/11/23 Eric Wong <normalperson@yhbt.net>:
> Tim Pease <tim.pease@gmail.com> wrote:

>> Thanks for the answer. My suspicion is that the Ruby 1.8 green threads
>> can be woken up, but the Ruby 1.9 system threads "do the right thing";
>> hence, the discrepancy in observed behavior. Good to know that it's
>> not a bug in 1.9.
>>
>> /me goes off to rework code
>
> Yeah, I expect thread.wakeup to only work on thread-aware things like
> sleeping on a condition variable or Thread.sleep.  1.8 wraps select()
> and uses that as the basis of its green thread implementation, so its
> harder to get around spurious wakeups.  For reliably waking up IO#select
> I'd just write a byte to a pipe (useful with signal handlers, too, see:
> http://cr.yp.to/docs/selfpipe.html)

Another approach would be to use #select with a timeout and regularly
check some condition.

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/