High CPU Usage Caused by Breakpoints

Thomas Gutzmann thomas.gutzmann at gutzmann.com
Mon Jan 17 12:17:38 EST 2005

Hi Richard,

> Does the mainstack have a default button?  Those throbbing buttons eat cycles like crazy.  Even 
>Apple's NavServices dialog will cause an app to go to 7-10%, but in Rev it's higher because of 
>the greater flexibility offered (it has to buffer the image to allow any backdrop behind it, not 
>just the OS stripes).

no, there was no default button. I quite Revolution, restarted it, reopened the main stack (the 
one without a default button), and saw the 50% CPU (on my beloved 1 GHz G4 PowerBook 17"), which 
went away immediately after removing all breakpoints (the CPU usage went away, not my beloved 

But you are right - I never noticed this: if I open a simple stack with a default button, CPU for 
Rev goes up from 2.5% to 25% - 30%. Thanks for this input; if I add resume/resumeStack and 
suspen/suspendStack handlers to the card script enabling and disabling the DefaultButton, the CPU 
usage drops as soon as I switch to another stack (without default button) or to another 
application. GREAT! I can sell the CPU ventilator at eBay now.

> But even with the extra work Rev is doing, on my system it never takes more than 25%.  Are there 
>pending messages or other background tasks which may contribute to this?

No. It was definitely linked to the breakpoints.

> Also, which version are you using?  In older versions a high spike for the throbbing default 
>button was more common, but this was reduced dramatically  in v2.5

Yes, 2.5 - the older version was not sexy enough and way too slow.


Thomas G.

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