development efforts on the Solaris side.

Theo Schlossnagle theo at
Wed Jan 9 17:42:36 CET 2008

On Jan 9, 2008, at 4:40 AM, Poul-Henning Kamp wrote:
> sendfile():
> 	Does the solaris sendfile guarantee that storage is no longer
> 	touched when it returns ?  Otherwise it's as little use as
> 	the FreeBSD and Linux versions.

I just conferred with a Solaris kernel engineer and...

Solaris guarantees that the address ranges (and file data) references  
as the source for data in calls to both sendfile() and sendfilev()  
will not be touched after control returns to the caller.

Destination guarantees are more complicated.  If the destination is a  
file, it may not be on disk after the call returns.  opening the file  
O_DSYNC or calling fsync() would be required.  However, I don't see  
how this aspect will apply to varnish at all as the destination is a  
network socket -- and for the sake of this discussion we really only  
care about the semantics of the source data and how that is accessed  
relative to the return of control to the caller.

Theo Schlossnagle
OmniTI Computer Consulting, Inc.
P: +1.443.325.1357 x201
F: +1.410.872.4911

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