Applies To:
  • CitectSCADA 6.x, 7.x

This problem is observed when a user launches and closes a popup window repeatedly. Doing so in certain conditions will show that the popup window takes longer and longer to display.

In order to observe this behavior the following conditions need to be satisfied.
  • On the popup page there must be many symbol set objects each with many array symbols on each.
  • The popup window is closed and re-opened repeatedly.

The cause of performance degradation is the act of freeing the page as you are able to launch the same popup window repeatedly with only a minor performance impact. As soon as you close a popup and launch another one however performance impact is then noticeable. Performance interesting does improve however if you continue to launch popup windows without freeing them.

Our investigations into this issue has lead us to believe that this performance degradation is due to the processes memory heap fragmentation when the window is freed. This is because there are so many small objects located on the page so there is extra overhead when re-using this memory when the next popup is launched.

There is no plans to resolve this issue. 

popup performance slow set array WinNew WinNewAt WinFree fragmentation heap memory