[Mapserver-users] Re: [Mapserver-dev] Thread safety: Using Mapscript from Java Servlet

[Steve Lime]

Good question, I'm not sure anyone knows exactly what would have to be
updated. My guess is that the biggest hurdles involve the map file and
logical expression parsing. Both of those make extensive use of flex and
bison output, neither of which are thread safe. While some work has been
done by Frank to make certain sections of code thread safe, a more
comprehensive inventory would need to be done. That's the first step.
Problem is, I don't know how to conduct such an inventory. Anyone got
any ideas?

Anywork should be done against 3.7 though, and should be done against
swig 1.3.17+. Have you played with that combination?

I'll try some google searches and see if there's a standard "procedure"
for achieving thread safety.

Steve

Stephen Lime
Data & Applications Manager

Minnesota DNR
500 Lafayette Road
St. Paul, MN 55155
651-297-2937
>>> Geo-IT-GmbH <info at geo-it.com> 12/17/02 11:25 AM >>>
Hi,
I managed to compile java mapscript without errors, using mapserver
release
3.6.3.
It is working fine from within a standalone java application but neither
from a servlet nor via SOAP (APACHE-SOAP).
In this case the JVM crashes with a core dump or does nothing at all. I
searched the mailing lists intensively and found that mapserver is not
thread safe and that seems to be the reason for this behaviour. I also
tried
implementing the servlet using SingleThreadModel but also without 
success.

What would be the effort to be done to use mapscript java from a servlet
(i.e. to make mapserver thread safe) ?
It would be great getting this to work ! We also have a good
C-Programmer at
hand who could help, but need some information on amount of work to be
done
beforehand from an insider.

Regards
Andreas Paukner-Ruzicka

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Geo-IT GmbH   -   Geoinformatik, IT-Services
Guggenberg 3, D-82380 Peissenberg (Germany)
Tel: 08803-498372, Fax: 08803-498373
eMail: info at geo-it.com  -  Homepage: http://www.geo-it.com
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