CPU ressource leak ?

[martialgallorini]

Hello,

i have just built a basic UI with some sliders and buttons without binding anything to it.

strange behavior : when the app has the focus, everything seems ok and CPU usage is around 5% on my core i7 quad cores. but as soon as the app is out of focus (i.e. i bring my chrome browser in front) then my ImGui app suddenly eat 97% of CPU, computer gets hot and fan is going mad.

A similar app built with ofxUI and bind to OSC precesses uses around 2,7 % of CPU no matter what

[jvcleave]

Weird - I am assuming on a Mac?

[martialgallorini]

yes on a macbook pro 15" late 2013

i will try under linux

[martialgallorini]

less effect under Ubuntu 14.04.3 but still...

also, same problem with the provided example.

[jvcleave]

@martialgallorini I created a test branch for this. The CPU use certainly is reduced when minimized but I am unsure of the implication on any background tasks (i.e. OSC, image processing, etc)

https://github.com/jvcleave/ofxImGui/tree/minimized-cpu-test

[martialgallorini]

hey. I gave it a shot. It is a bit better but issue persists.

As i said, when app is in the front, it uses much less CPU.

ofApp in front and Chrome in the back :

Chrome in front with ofApp in the back :

oF v09 on Macbook Pro core i7 under OSX El Capitan

[jvcleave]

The code is only concerned when the app is minimized. GLFW_FOCUSED (as opposed to GLFW_ICONIFIED ) may work better for background

[martialgallorini]

Yes i see. This sure is better. But this doesn't solve the problem...

Do you think this is related to the OS ?

[jvcleave]

It may partially be related to the OS. Also depends if OF has anything to assist with dealing with app focus in place.

Why doesn't it solve the problem?