Resizing Front Panel Slows Down the Execution of LabVIEW Application

Updated Jan 16, 2018

Reported In


  • LabVIEW Full
  • LabVIEW Professional
  • LabVIEW Base

Issue Details

I observed that the execution speed of loop containing Call Library Function Node VI drastically slows down when resizing the Front Panel Window. Why is this happening?


Most probably the reason why your code is getting slower is that you have selected Run in UI thread while configuring the Thread Section of the Function Tab in Call Library Function.

In that section, you can choose in which thread your DLL will be executed. 

If you have selected Run in UI thread, the Call Library Function Node switches from the thread the VI is currently executing into the user interface thread to execute your DLL. Since resizing forces the Front Panel to be redrawn– and this operation consumes significant amount of time– the jitter may be introduced and you may observe that your code executes longer than usually.

To avoid this from happening, you should rather choose the DLL to Run in any thread. In this mode, Call Library Function Node continues in the currently executing thread.

Before you configure a Call Library Function Node to Run in any thread, make sure that multiple threads can call the function simultaneously. If you don't know if your DLL is thread-safe and can be executed simultaneously click here.

Additional Information



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