09-24-2009 10:14 AM
I have a fairly large application that connects to an Oracle database.
After long idle time, the database disconnects, so I thought I would put matters in my own hand and disconnect after 1 hour of no events in my event structure.
Then I used the 'Wait for Front Panel Activity' vi to wait until the user comes back to the application to reconnect.
However, it seems that under certain circumstances the application freezes up.
Could it be that system events (going to sleep, or screen saver etc...) cause the application to freeze up while it is waiting for front panel activity?
Anyone else seen this happen?
Thanks.
-Nils
09-24-2009 12:29 PM
09-24-2009 02:58 PM
09-24-2009 03:10 PM
If you put the creat from panel activity back into your program. Look at the ammount of processing that is required to run when the program is in sleep mode after the hour. Then put the ok and meggase dialogs back in and see again. The difference may be that you are not going as fast witht he message dialogs so it will take much longer to see the problem. It does not mean that it is not there. I once had one that took a week before it would cause the same issue.
09-25-2009 02:02 PM
Thanks for the suggestions. Let me try this out. I still have the compiled executable with the wait for front panel activity. It was sitting overnight and is now frozen. CPU usage is 0%, mem usage is 15,096 K. Total cumulative CPU time is 0:00:08, peak memory usage is 123,136 K.
The new executable, with dialog box has 0:00:05 of CPU usage after just a few clicks on the front panel, and Peak mem usage of 117,232 K.
After a few hours, it is not frozen, has 0:00:08 of total cpu usage and Peak mem usage still 117,232 K.
I don't think there is any leak, and I think certain system events cause the LabVIEW 8.6 runtime environment to freeze while waiting for front panel events.
-Nils