Hello!

Apologies for being off-topic, but we're experiencing something similar to your support case https://www.appeon.com/standardsupport/search/view?id=3736 - our customers are crashing frequently and we'd love to understand how you approached investigating the issues you reported.

If you could spare some time to share your insight, we'd be very grateful... please contact me at cheale.AT.brighthealth.ca

Many thanks!

Chris Heale 

The following image illustrates the objects in the example program contained in BareExample.zip

For convenience I added a compiled version of the DLL, but feel free to compile it yourself from dllmain.cpp. One only requires the PBNI SDK for compiling.

• n_pbni_v1 does nothing but showing a message-box during construction/destruction
• n_pbni_v1 shows a message-box during construction/destruction and triggers the constructor of a derived class.
• n_base does the same as n_pbni_v1 but is plain PowerScript
• n_derived_v1 to ..v3 also do nothing but showing a message-box during construction/destruction

The application object implements the open-event which does the following:

n_derived_v1 ln_dv1
n_derived_v2 ln_dv2
n_derived_v3 ln_dv3

// n_derived_v1's base class n_pbni_v1
// does not explicitly call the 
// constructor/destructor of its
// descendant. This default behaviour 
// leads to non-initialized objects
// and may cause memory-leaks 
MessageBox("", "CREATE n_derived_v1")
ln_dv1 = CREATE n_derived_v1
MessageBox("", "DESTROY n_derived_v1")
DESTROY ln_dv1

// n_derived_v2's base class n_pbni_v2
// explicitly calls the constructor/
// destructor of its descendant. This
// is the correct behaviour but it 
// can cause trouble when opening the 
// painter. 
MessageBox("", "CREATE n_derived_v2")
ln_dv2 = CREATE n_derived_v2
MessageBox("", "DESTROY n_derived_v2")
DESTROY ln_dv2

// The following shows the expected behaviour:
MessageBox("", "CREATE n_derived_v3")
ln_dv3 = CREATE n_derived_v3
MessageBox("", "DESTROY n_derived_v3")

n_derived_v2 and n_derived_v3 show the expected behaviour during execution. As stated above the problem is induced by the painter which creates instances of the native base class when it is opened in the IDE:

• clicking on n_pbni_v1 to open the coresponding painter would first popup the two messages:
  and
• clicking on n_pbni_v2 yields the same amount of popups
• clicking on n_derived_v1 yields four messages due to two instantiations:
  1. n_pbni_v1::constructor
  2. n_pbni_v1::constructor
  3. n_pbni_v1::destructor
  4. n_pbni_v1::destructor
• clicking on n_derived_v2 yields six messages
  1. n_pbni_v2::constructor
  2. n_derived_v2::constructor
  3. n_pbni_v2::constructor
  4. n_pbni_v2::destructor
  5. n_pbni_v2::destructor
  6. n_derived_v2::destructor
• clicking on n_derived_v3 yields zero messages, which is the behaviour I would expect for above cases too.

As implied by the messages shown by clicking on n_derived_v2, the IDE painter first creates an instance of the concrete class (i.e. n_derived_v2) and afterwards an instance oft its immediate anchestor class (i.e. n_pbni_v2). Causing lots of Messages popping up.

What version/build of PowerBuilder?

I've created several non-visual PBNI extensions and haven't had any troubles like you describe. I would guess that there is something wrong with the C/C++ code in the extension.

If you can post it somewhere, I would be willing to take a look.