Profiling Qt app with very Sleepy , how to analyze the results?
Im trying to find why my Qt application get delay in some point for second , this sec delay happens each add to list operation , and way i used the free profiler "Very Sleepy" and it gave some snapshot that i have hard time to analyze. here is the top snapshot : first of all it seams that this winapi methods takes long:
and there is no stack print . the second method that taks long is :
and in this stack trace i see heavy calling to QSettings::allKeys coming from QtCore4 i dont call QSettings::allKeys
and then i have :
and here i do create images from bytarray info i download from the web , small 50X50 images using :
@QImage thumbnail = QImage::fromData(bytarray );@
how can i save here and maybe stop this app delays?
You did not provide enough information to come up with any sensible suggestion for improvement.
Generic idea: What happens during each "add to list operation"? Does this addition ripple through the code, triggering updates in other places? Does it require redraw operations? How expensive are those?