2008/784 Sendfilev Behavior Change

[Roland Mainz]

James Carlson wrote:
> I am sponsoring this fast-track request for Vasumathi Sundaram.  The
> timer is set to 01/02/2009 in light of the coming holidays.  Please
> speak up if you need more time than that.
> 
> In an offline discussion, the project team went to lengths to find any
> sendfilev users,

Erm... ksh93 had support for |sendfile()|/|sendfilev()| support but it
was breaking UDP networking support (and there was no reliable way to
check this) and we removed this capability again (it gave a good
performance improvement for sending larger files but propper
cross-platform support is more important in this case).

> 2. Solution
> 
>   sendfilev is modified so that the output behavior is not the same as
>   writev() and when multiple threads attempt to write to the same
>   output file at the same time.  Instead, the result of the combined
>   operations is undefined.  The applications that use sendfilev() will
>   have to use their own synchronization mechanism to ensure a
>   consistent output.

... which effectively means: A shell with thread support or any other
language environment (e.g. java) shouldn't use |sendfilev()| when files
are involed, right ?

----

Bye,
Roland

-- 
  __ .  . __
 (o.\ \/ /.o) roland.mainz at nrubsig.org
  \__\/\/__/  MPEG specialist, C&&JAVA&&Sun&&Unix programmer
  /O /==\ O\  TEL +49 641 3992797
 (;O/ \/ \O;)