How do I find out why the render loop is running?

David Hill David.Hill at
Tue Sep 30 13:53:33 UTC 2014

On 9/29/14, 7:43 PM, Kevin Rushforth wrote:
> I would suggest using the pulse logger, but it doesn't look like that logs the reason for a pulse. It will show renderer activity, though, which might be useful.
> Typical reasons for a pulse to run are:
> 1) A an active Timeline or AnimationTimer
> 2) A control, such as a ProgressIndicator, that uses animation to display changes (even if the control is scrolled off the screen)
One common control animation that is easily overlooked is a text cursor, which is animated to blink - when the control has focus.
> If the app is minimized (iconified) then the renderer shouldn't actually do anything though the pulse is running, but any animations will still run.
> -- Kevin
> Mike Hearn wrote:
>> My app consistently uses about 10-15% of a CPU even when off screen and
>> nothing is being animated. I had assumed JFX would idle in this case but it
>> seems not. I suspect I've done something that is forcing the system to
>> "pulse" no matter what, but I don't know where to begin investigating this.
>> Profiling just shows lots of time being spent in quantum.

David Hill<David.Hill at>
Java Embedded Development

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