Well this is an odd one I must say.
I have an application where I would like the front panel to disappear
at the user's discretion so it's not in the way while it's processing
information in the background. To process the information I have
a custom DLL and to check the progress of the custom DLL, I have a
routine that I can call that will return the status. So the
information processor is called and it just runs in the background, and
then the status routine is called in a parallel loop until the status
routine determines that the processing is finished. When the
status routine says it's done, the parallel loop exits and another
routine sets a flag for the processor to exit (so everything quits).
In order to make the DLL calls work right as far as execution
sequencing, they are called as re-entrant. I stumbled across that
orginally because it was locking things up when I was trying to call
them in parallel.
I have no memory leaks in the external DLL calls and this is verifiable
by running the processing routine indefinitely while checking the
status indefinitely. The problem is when I open a VI reference to
the main VI then make it's front panel not visible. At that
point, memory usage starts increasing by 400k/sec (which is larger than
the entire DLL). It will eventually just crash the system.
If I set the front panel to be closed on a timer (for several seconds
say), the memory usage will increase for that amount of time and then
stop once the FP is opened again.
I know this is really difficult without having some code to look at but
it would be really hard for me to dumb down the code to get the problem
in a simple set of VI's to look at. I'm wondering however if the
reentrant DLL calls are having some weird interaction with windows
since I'm guessing at a lower level, the application's window handle is
invalidated when the front panel is closed. I'm wondering if the
reentrant DLL status call is having new memory allocated for it every
time it is called in the status loop. I just can't figure out how
that has anything to do with the front panel being closed though.
Any suggestions on things to try or look at?
