From: "Florian G. Pflug" <fgp@...>
Date: 2003-05-19T08:38:34+09:00
Subject: Re: C Extensions blocking all ruby threads

On Mon, May 19, 2003 at 02:56:56AM +0900, Idan Sofer wrote:
> 
> 
> > .) Maybe mysql has no non-blocking api. Then the maintainer can't fix this
> > either.
> Perhaps he can, TCPSocket class for example is non-blocking.
Yes, but there is a non-blocking api to file reads and writs in unix. 

> I understand this has something to do with rb_thread_select(), However
> I've searched in
> the archives and found no much details about it's behaviour(intern.h
> wasn't very helpful
> resource as well)
rb_thread_select offers the same functionality as unix select(), but lets
other threads run instead of blocking until one of the fd's you select() on
becomes readable or writeable.

Using rb_thread_select in a ruby c-extesion has the same effect as using
normal select() in an non-ruby posix-threaded app.

> I might be willing to attempt patching the mysql extension myself, If
> someone can pinpoint
> to a source of information about rb_thread_select().
Well, look at some extesions that use it (the async_* calls in the postgres
extension are a good example), and compare this to the documentation of the
select() syscall. That should give you a clear picture of whats going on.