LabWindows/CVI
run / quit user interface and memory clean up
Hi,
may be I simply miss a coffee, but here is my problem: I have a main function and a quit callback in a standard configuration, i.e. as follows:
int main ( int argc, char *argv [] )
{
...
RunUserInterface ();
DiscardMenuBar ( popup_menubar_handle );
DiscardMenuBar ( menubar_handle );
DiscardPanel ( panel_handle );
return ( 0 );
}
int CVICALLBACK Quit ( int panel, int control, int event, void *callbackData, int eventData1, int eventData2 )
{
if ( event == EVENT_COMMIT )
{
FreeDynamicMemory...
FileCloseFiles ...
QuitUserInterface ( 0 );
}
return ( 0 );
}
On the panel, there is a graph with plots etc. If I quit the program via the quit callback (i.e. a Quit button), everything is fine, no memory leak.
If I try a modified version as shown below, plots are not freed after the program has finished, resulting in a memory leak as shown by the resource monitor:
int main ( int argc, char *argv [] )
{
...
RunUserInterface ();
return ( 0 );
}
int CVICALLBACK Quit ( int panel, int control, int event, void *callbackData, int eventData1, int eventData2 )
{
if ( event == EVENT_COMMIT )
{
FreeDynamicMemory...
FileCloseFiles ...
DiscardMenuBar ( popup_menubar_handle );
DiscardMenuBar ( menubar_handle );
DiscardPanel ( panel_handle );
QuitUserInterface ( 0 );
}
return ( 0 );
}
I have also tried reversing the order in the quit callback, with the same result:
int CVICALLBACK Quit ( int panel, int control, int event, void *callbackData, int eventData1, int eventData2 )
{
if ( event == EVENT_COMMIT )
{
FreeDynamicMemory...
FileCloseFiles ...
QuitUserInterface ( 0 );
DiscardMenuBar ( popup_menubar_handle );
DiscardMenuBar ( menubar_handle );
DiscardPanel ( panel_handle );
}
return ( 0 );
}
So only the first variant works properly and I could be happy.
However, I do not understand why version 2/3 do not work.
Second, the first variant does not work if I also have installed a main callback, see the other thread here That's why I tried variants 2 and 3 but failed...
Thanks for the coffee 
