PHP/Mapscript, apache2, mod_php - What is the status?

[Frank Warmerdam]

Stephen Woodbridge wrote:
> Benjamin,
> 
> I never got any answer to this on list. It would be nice if there was a 
> plan to  change the code to be more thread safe, but my guess is that 
> will not happen without additional funding.
...
 > I think DM Solutions would have to address any
> issues specific to PHP/Mapscript.

Steve,

I think you have a point that if thread safe mod_php use of mapserver
is important to people, someone is going to have to put forward money or
developer time to make it work smoothly.   I personally think it wouldn't
be that hard to get it going modulo a few risky areas.  And the more
mapserver users depending on thread safety, the move loving mapserver
thread safety will get.

DM Solutions (or perhaps MapGears) would be a logical place to direct
money to address this issue.

In the future, it is my hope that many organizations interested in MapServer
will become sponsors of OSGeo listing MapServer as the project they want
to direct the majority of their support to.  How that money gets spent
would (likely) be up to the MapServer PSC, but if the sponsors beat the
drum about mod_php support, I'm sure some would go in that direction.

The other (in some ways preferrable) approach is for a decent developer
with a long term interest in mod_php support to roll up their sleeves
and work away at it.  I'm sure DM Solutions and the rest of us would be
supportive and cooperative.

> Sean Gillies did a lot of work on thread safety (as did others) and wrote:
> 
>   http://mapserver.gis.umn.edu/docs/faq/thread_safety
> 
> This document also lays out what some of the major areas (Mapserver 
> parser, PROJ, GDAL, DB Connection pooling) that could be improved to be 
> more thread safe without putting coarse locks around those areas.

Yes, this is a useful guideline.  Note that some areas (ie. GDAL) use
a "big lock" and so could suffer congestion in heavy multi-threaded use,
but should be pretty safe.  Others, like OGR don't have locking yet and
are just very dangerous right now.  Like you, I also think there are
some specific PHP related issues about which I have no clue.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGF, http://osgeo.org