is Mappoint thread safe

[Wilfried]

Hi,

I'm using mappoint (the object model) for a very lengthy operation and like to do it in a background thread. The map is not visible as whell as no other part of the ojbect. Some has done this before or know some special behave I should be aware off ?

[Jeurink]

I'm changing symbols, shapes etc. of the map from differend threads.
I've not found unexpected behavior so far, but that is no guarantee offcourse.

I think MapPoint works as follows:
when you update a property (eg. the location property) an event is raised,
and catched by the mappoint engine (that has its own thread) and reponds with an updated pushpin location.

but as said, I'm not sure.

succes with your application

[Wilfried]

Hi,

Thanks for reply. I will give feedback when I do the threaded thing (probably in a few day)

[Winwaed]

I think Jeurink is along the right lines. If you're telling MapPoint to do things from an external application, then your call will always be in a different thread. So it probably doesn't matter - as your own logic makes sense.
Eg. using objects before they are created, or changing and querying them at the same time.

I do have a couple of applications that use multi-threading, but all MapPoint code is one thread. The second thread looks after the GUI.

Add-ins run "in-thread", so they're more likely to have problems. I guess you could try spawning a new thread in C++,Delphi,etc and see what happens, but I know VB won't let you do that.


Richard

[Wilfried]

Hi Richard,

My plan is to create / destroy the obect and use it in same thread context to avoid any complications. I did not try it at the moment.

Reason is that I have application receiving positions that possible are not on a digitized road. So I start running in circles until I can say: 'person is 35 meter SW of 'churchill road 322'.

This take mutch time specially if the position is far away of a road. So that's the reason of thread question.

[Winwaed]

I guess that might be practical with the advent of multi-core (and hyperthreaded) cpus. Most of us are stuck on single cpu systems though


If you've plenty of memory, you could always have two MapPoint instances.


Richard