thread safe implementations

[Dan Barron]

Sean/Umberto,

I was able to compile java mapscript - however when I try to load the
library within the sample java app to prove it works, I get an
"UnsatisfiedLinkError" with "undefined symbol: msGMLWriteQuery" - I've
looked around and can't seem to figure out what I am missing.  Any ideas
why I am getting this?

Thanks,

Dan


At 07:45 AM 11/4/2004, Sean Gillies wrote:
>Dan,
>
>Truly, the Java mapscript had been abandoned for a while.  Then Umberto
>stepped forward and contributed a new Makefile and patches, and it seems
>to be in a workable state.  I've also fixed the most obvious threading
>issues in MapServer itself.
>
>I'd really appreciate it if the two of you would download the new 4.4.0
>beta releases and try them out.  Make some servlets and pound on them
>and
>see if Java mapscript is reliable.  I think this is really the only way
>to know for sure.
>
>BTW, once you have MapServer itself compiled, the Java Makefile in 4.4.0
>works fine with FC2.
>
>Sean
>
>On Nov 4, 2004, at 8:12 AM, Dan Barron wrote:
>
>>Umberto,
>>
>>I'm not going to try to recreate the functionality of the cgi - I'm not
>>fully sure yet what absolute path I will take - I really have not done
>>much
>>threaded java code.  I've looked at the java mapscript - and your map
>>server wiki entries for compiling java mapscript - I'm not convinced I
>>have
>>a good compile yet (platform is Fedora Core 2).  Is the java mapscript
>>viable at this point?  I have read posts from earlier this year saying
>>it
>>looked abandoned?
>>
>>I would really like to get to an all java solution if possible - I
>>currently use a combination of java/php (java opens a connection to a
>>php
>>script then parses the returned data) - not the best but it seems to
>>work
>>fine under light loads.
>>
>>I'd be interested to hear more about what you are up to - it sounds
>>interesting.  I would really like to just build a threaded front end
>>(maybe
>>a thread pool?) to the map server functionality via java mapscript and
>>nothing more.
>>
>>Thanks,
>>Dan
>>
>>At 11:51 PM 11/3/2004, unicoletti at prometeo.it wrote:
>>>Dan,
>>>if by creating a java implementation you mean writing a web app to
>>>deliver the
>>>same (or  subset) of the functionality the cgi does, then I am
>>>writing one.
>>>
>>>I think I am one of the few java mapscript users around :-)
>>>
>>>Regards,
>>>umberto
>>>
>>>Quoting Sean Gillies <sgillies at FRII.COM>:
>>>
>>>>Dan,
>>>>
>>>>It's not clear to me what you mean by creating a java implementation
>>>>on your own.  Implementation of what?  Do you mean a programming API
>>>>like the php mapscript module?
>>>>
>>>>If this is what you mean, you should look at the Java stuff that
>>>>you can generate using SWIG.  In mapserver versions 4.2.4+ and in
>>>>the 4.4.0 beta1 there is a Java makefile under
>>>>mapserver/mapscript/java.
>>>>It seems to work, but as I've said -- I'm not a Java user and so am
>>>>not beating on the Java mapscript module heavily enough or often
>>>>enough to say anything about its readiness.
>>>>
>>>>Sean
>>>>
>>>>On Nov 3, 2004, at 10:37 AM, Dan Barron wrote:
>>>>
>>>>>Hmmm - I was really hoping someone had done (or attempted) a java
>>>>>implementation - I'm not versed in Zope or Python.  Well, I guess I
>>>>>will
>>>>>attempt to create a java implementation on my own.
>>>>>
>>>>>Thanks Sean.
>>>>>
>>>>>Dan
>>>>>
>>>>>At 01:10 PM 11/2/2004, Sean Gillies wrote:
>>>>>>On Nov 2, 2004, at 10:47 AM, Dan Barron wrote:
>>>>>>
>>>>>>>Hello,
>>>>>>>
>>>>>>>Just curious what the current consensus and recommendations are
>>>>>>>for
>>>>>>>creating a thread safe front end or wrapper for mapserver in
>>>>>>>either
>>>>>>>php or
>>>>>>>java? I'm assuming that mapserver is still not thread safe - that
>>>>>>>correct?
>>>>>>>
>>>>>>>Thanks!
>>>>>>>
>>>>>>>Dan
>>>>>>
>>>>>>Dan,
>>>>>>
>>>>>>I caught and fixed three sources of potential threading problems
>>>>>>before
>>>>>>the 4.2.4 release and these fixes will also be in 4.4.0.  I think
>>>>>>we're
>>>>>>close to thread safety, but it's hard to say without more testing.
>>>>>>  As
>>>>>>far as I know, my ZMapServer (Zope + Python mapscript) software is
>>>>>>the
>>>>>>only thing out there that is using MapServer in a multi-threaded
>>>>>>environment.  It works, but is not a complete proof of thread
>>>>>>safety.
>>>>>>
>>>>>>There remains much work to be done to in improving MapServer's
>>>>>>threaded performance.  The single lexer for parsing mapfiles and
>>>>>>class expressions is a bottleneck that will be addressed in the
>>>>>>future.
>>>>>>
>>>>>>cheers,
>>>>>>Sean
>>>>>>
>>>>>>--
>>>>>>Sean Gillies
>>>>>>sgillies at frii dot com
>>>>>>http://users.frii.com/sgillies