[mapserver-users] Threads and Mapscript

[Stephen Woodbridge]

Harald,

I believe Frank or Dan responded to my message about mapserver thread
safety and corrected my mis-informed statements. Please concided my
statements  erroronious - you need to review their response for the
correct information.

A lot of people use mapscript built as CGI without a problem.

-Steve W.

Harald Wehr wrote:
> 
> Stephen Woodbridge wrote:
> 
> > Harald,
> >
> > mapserver is not thread-safe, I think the developers have start putting
> > mutex locking it but as you have found out it is not finnished. It also
> > crashes with PHP/mapscript if you do NOT build it as a CGI program.
> >
> > -Steve W.
> 
> Hi Steve,
> 
> I'm referring to our mails in march this year.
> 
> You write that PHP/maspcript crashes too. How do other people handle
> this problem or is mapscript not used at all?
> 
> Of course I can call the cgi-program from a java-servlet, but thats not
> so comfortable and not the intention of mapscript.
> 
> THanks a lot for your help.
> 
> Harald
> 
> >
> > Harald Wehr wrote:
> >
> >>Using a cgi-script on a server for every request a new thread is opened,
> >>isn't it?
> >>
> >>I use mapscript in a servlet. Every request makes a new thread. I save
> >>one mapObject in one java-session. Several requests (from different
> >>browsers) produce different mapObjects. Everything works right until
> >>here. I have different objects with different c-pointers.
> >>
> >>Calling mapscript from one browser works fine. Calling it from another
> >>browser sometimes crashes my servlet-engine. It writes:
> >>"Unexpected exception outside virtual machine
> >>Function=msDrawRasterLayer+0x694
> >>Library=/urs/local/lib/libmapscript.so"
> >>This happens when i call the map.draw()-method. Do you have any suggestions?
> >>
> >>What happens when i call
> >>"mapscipt.saveImage(pointer,"file.png",2,1,0,95)" from different
> >>threads? Is this thread-safe even in all depending libraries?
> >>
> >>Asking the "mapscript.get_ms_error" from different threads I always get
> >>the same c-pointer of the error. Is this right? Can I somehow get
> >>error-Objects related to specific thread?
> >>
> >>Harald
> >>
> >
> 
> --
> Hochschule Harz
> Projekt Mobiharz
> Tel. 03943/626654
> Email: hwehr at hs-harz.de