anything special about 60 seconds?

OpenGL Development JOGL Development
#1

I measure my framerate as an avergae over 5s. It seems every 60s I get a framerate average drop of around 5%. I’ve shut down all my other threads and there is nothing happening on the gui. Any ideas? Could it be one of the garbage collectors kicking in at regular intervals? or the hotspot compiler? or could it be something JOGL based?

Cheers

Peter

#2

btw, I tried visualgc, but couldn’t see anything unusual with the gc. I get an Eden collection about every 10s, but nothing on the Old Gen.

cheers

Peter

java version “1.5.0_06”
Java™ 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
Java HotSpot™ Client VM (build 1.5.0_06-b05, mixed mode)

#3

Have you tried instrumenting the JOGL demos such as the Gears demo with FPS computation as you’re doing? Does the problem occur there as well? Nothing is going on with that time interval in JOGL.

#4

Try:

-XX:+PrintCompilation

and

-verbose:gc

#5

I’ll have a play with the gears stuff at the weekend.

swpalmer: thanks, but visualgc show all this info and its clearly nothing to do with gc or hotspot compilations.

maybe its just something in windows.

cheers

Peter

#6

mystery solved! I tried the gears demo with my fps code and saw the same problem. I tried it on a second box and also saw the same slowdown once per 60s, and it was something to do with Java using some cpu resources for a short time. But it turns out it was the eclipse development environment! doh! should have thought of that, just saw java and assumed it was the application :slight_smile: sorry to waste you time guys. But it nice to see the gears demo again :slight_smile:

Cheers
Peter

#7

One (minor) sad part about Java client side is multiple “java.exe” named processes even that applications are nothing to do with each other. WinXP and Win2K collapses similar names to the same taskbar icon.

We should have a licensed rights to take java.exe from JRE/bin folder and copy to “c:/myapp/myapp.exe” name. This should solve this problem.

  • or should we take windows/system32/java.exe or javaw.exe file actually. But then I dont know if user updates the JVM installation and we use exe from the previous version. It might produce compatibility problems.