Timers stop executing all of a sudden!

Question

Apologies for a lengthy question :-)
I have a dedicated form to which a timer is attached and it polls table every 30 sec to search for some data.
The form is opened on load of the main form and is present through out the app is open.
The timer suddenly stops executing at certain points in time, mostly when there are alerts displayed on the screen. It never expires thereafter, until i go and click on the notification form. Mysteriously as soon as I click on the notification form, the timer expires and it works properly.
three things I require help on....
1. Any explanation as in why the timer stops working and resumes as soon as I click on the form?
Note: There are no "when new block instance" triggers on the form. It has only new-form instance in which we create timer and when timer expired trigger.
2. Any solutions to the above problem. Can I move the focus to that window some how? Where should I use "Go_form"?
3. Any alternatives to this approach to query data periodically from the table?
Thanks and Regards
Shree

Answer 1

Hi
I thing (and not sure of) the reason that timer halt on certain points in time is that Forms does not support multithreading, that means the whole program is running instructions one by one, and if the program reaches instruction that requires user intervention, any instructions following that will not execute and the program enters a loop waiting the user, once the user interacts, the program continue with next instruction. Timers are instructions inside the body of the program and any timer will not execute its triggers if any kind of user intervention is required.
Note : there is a different behavior when using CALL_FORM or OPEN_FORM, one continue executing the following code, and the other does not.
I do not know why this behavior exists in Forms, because Timer (by its name) should not stop executing its triggers no matter what happen in the form.