*BSD News Article 89984


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From: Michael Hancock <michaelh@cet.co.jp>
Newsgroups: comp.programming.threads,comp.unix.bsd.freebsd.misc
Subject: Re: [??] pure kernel vs. dual concurrency implementations
Date: Sun, 23 Feb 1997 14:48:44 +0900
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Bryan O'Sullivan wrote:
> 
> m> Ok.  Just to confirm, there are dual concurrency implementations
> m> that do the non-blocking thing, right?
> 
> Not that I am aware of; after all, there is no reason to jump through
> hoops to lay non-blocking behaviour underneath blocking calls in a
> two-level implementation.

Ah, that explains why I got odd replies in some of my private mail on 
this topic before I posted.

People have implemented both two-level and pure userlevel on the same 
platform though.  I guess there were done independently to address a 
deficiency of the other model.

Regards,


Mike Hancock