httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ben Laurie <>
Subject Re: threads
Date Sat, 17 Aug 1996 16:35:37 GMT
Robert S. Thau wrote:
>   That is, the compatibility layer may as well be the rsthreads API.
> As the author of RSthreads, I respectfully dissent.  RSthreads includes
> some functionality which many threads packages and interfaces do not
> support, and while some of that is stuff which Apache would require in
> some form anyway (e.g., per-thread alarms), and might as well be part
> of the compatibility layer for that reason, a lot of it isn't.

Point taken. In fact, I'm only implementing those features which Apache
actually uses.

> In particular, there's a nigh-on universal convention in RSthreads
> that a timeout value may be specified for any operation that can block
> a thread (e.g., wait until notify of a particular condition, or for
> ten seconds, whichever comes first) which would be somewhat awkward to
> support on top of other threads interfaces (pthreads in particular).

Hmmm ... Apache may not use all of the possible timeouts but it does use some
of them. If we can avoid some altogether it would be nice to know which ones.

> This sort of thing *does* have its uses --- for instance, the
> RSthreads DNS-support code uses it internally to manage retransmits to
> the nameserver, by waiting until DNS-dispatch has notified the waiting
> thread that its response has arrived, *or* until a timeout has
> elapsed.  However, I've deliberately tried to avoid it in the main
> apache-XX server code, to avoid creating artificial barriers to ports
> on top of other threads layers, and I don't think it should be in a
> compatibility-layer interface for the same reason.

OK, I'm inclined to agree with all this but it doesn't get me any further with
Win32 until we can agree what the compatibility-layer interface is. It also
leads me to wonder whether the more advanced features of RSthreads should
(could?) be implemented above the compatibility layer so we can use them with
impunity on all platforms?



> rst

Ben Laurie                  Phone: +44 (181) 994 6435
Freelance Consultant and    Fax:   +44 (181) 994 6472
Technical Director          Email:
A.L. Digital Ltd,           URL:
London, England.            Apache Group member (

View raw message