Timing problem

[VizMars]

Sorry, but I don't know how to provide a code that reproduces the issues without including the eyetracker commands. I excluded the other parts of the code because these are mainly functions that are used for the communication with the eyetracker.
Does

rec_data = yield viztask.waitDirector(el_rec_thread)

prevent later lines of code in the task function from executing until the timer expires? That poblem is that I need the el_rec_thread to check if the recording is aborted and for (EyeLink) program termination. If I use

yield viztask.waitTime(2)

then it seems impossible for me to implement this recording thread.

[VizMars]

Is there an event or function that can tell me whether the rendering of the world is finished?