show subvi FP via top reentrant top VI

[richjoh]

I am trying to set my Runtime Menu Help/About popup VI to work when the top level VI is a reentrant. When my top VI is NOT reentrant its work OK --the  subVI shows its FP "frontmost" or "foremost" using a VI property node (inside an Event stucture). At this time this appllication uses LV7.0.

How are subVI run when the top VI is reentrant, do subvi run reentrant too? If not, must the subVI property be changed to reentrant (it is already set to "match caller vi" under "VI Property/ Execution" Menu?  Thus I don't see a need to set subvi reentrant too. Is this a problem when I use an event stucture to bring the "About.vi" to the front?

[Justin D]

Hi richjoh,

The reentrancy of one VI does not affect the execution modes of the VIs it calls.  That is to say just because a reentrant VI calls a subvi, it doesn't automatically mean the subVI is reentrant.  Your "About.vi" shouldn't have to be reentrant unless you expect that it could be called from multiple places in your code at the same time.  When you select the "same as caller" option under VI properties, this doesn't affect the reentrancy of your code.  This only chooses the thread that your code executes in.

I hope this helps,

Justin D.

[richjoh]

Justin, thanks for the response,

I solved my dilema by removing my "About" vi from the FP Event structure and put it to a (plain) Loop. For whatever reason (and maybe this is documented somewhere) the FP vi Event Stucture did not execute my "About" when I set the FP to reentrant.  My runtime menu was also not functional at runtime when I set the FP vi to reentrant.

Again this is LV version 7.0. (I'm not sure if the above functionality is intended or is it a bug)?