From owner-freebsd-hackers@FreeBSD.ORG  Thu Nov 23 12:34:38 2006
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From: Ivan Voras <ivoras@fer.hr>
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To: Robert Watson <rwatson@FreeBSD.org>
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Cc: freebsd-hackers@FreeBSD.org
Subject: Re: Kqueue write event position?
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Robert Watson wrote:

> My concern with this idea is that kqueues are not really intended to 
> provide an event stream, rather, notification of a condition.  As writes 
> often come in batches, it's likely that by the time the kevent is 
> received, several writes will have occurred, but only a single event 
> notification will be present.  Is the application you have in mind able 
> to benefit from what is effectively "polled" sampling of writes?  Does 
> it benefit in the presence of writes from concurrent writers, where 
> things like the position and length may depend on which of two or more 
> writers wrote to the file most or least recently?

Yes, this was the next question I wanted to ask. I was counting on 
receiving just the stream of events you describe - receiving random 
samples of it would be as useful as only receiving write notifications.

Thanks for clarifying this!