Here's a suggestion:
Mark the time when starting the thread.
Then during the script run, add a time check action and compare the time difference with your desired value.
-> Take appropriate action.
For multithreading you should use resources. There are additional
settings for each resource, just double click it inside resources pane.
There you can fine tune your settings to achieve desirable behavior.
In your case you should set resource to use each line only once,
and set max symultanious usages to 1. Check other settiings too
to make it work the way you want.
