PSARC/2007/580 Integrate libevent into Solaris

[James Carlson]

Bart Smaalders writes:
> James Carlson wrote:
> > Bart Smaalders writes:
> >> 	It is possible to disable support for any of these event notification
> >> 	mechanism by setting the relevant environment variable. This is
> >> 	documented in the man page.
> > 
> > That's just frightening.  This appears to mean that the internal
> > design of the library can (in effect) be altered by the end user at
> > run time.
> > 
> 
> You mean like LD_LIBRARY_PATH to select an alternate malloc 
> implementation, interpose audit libraries, and the like?

Which, of course, has run many folks into trouble and thus has setuid
safeguards as well as frequent "don't do this" warnings.

>  Or change
> the default library search order w/ LD_CONFIG?

Same issue.

>  Or to select the number
> of processors used w/ NCPU?

That seems a bit different, as it doesn't actually choose an different
implementation.

>  > Any clue why this is a reasonable thing to include in this delivery?
>  > Is there any advantage to allowing the end user of an application
>  > linked to libevent to "tweak" the underlying mechanism?
> 
> There's a long history in all sorts of places of modifying application
> behavior with environment variables.  The selection of dispatching 
> mechanism used internally inside libevent seems to be just yet another
> choice.  Given the history of bugs in all the mechanisms available -
> /dev/poll, kqueues, epoll, etc, providing a mechanism to select
> a possibly less broken implementation doesn't seem that unusual.

I see.  If the person integrating this library is adamant that
preserving this "feature" really is the right thing to do on Solaris,
I guess I'll back down.  I'm not prepared to derail over it.  It just
doesn't seem wise to me.

> > I can understand perhaps it when compiled with -DDEBUG, but it seems
> > strange and potentially hazardous otherwise.
> > 
> >> 	In addition, libevent implements interfaces that provide additional
> >> 	functionality for embedding an event driven http server and buffered
> > 
> > An http server?
> > 
> As far as I know, this was removed from all but the man page.

OK ... so that's not part of this project, right?

-- 
James Carlson, Solaris Networking              <james.d.carlson at sun.com>
Sun Microsystems / 35 Network Drive        71.232W   Vox +1 781 442 2084
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