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:

    @Name,Exclusive,Inclusive
    GetModuleFileNameA,983.451654,983.451654,87.500001,87.500001,kernel32,[unknown],0 @

    and there is no stack print . the second method that taks long is :

    @GetLastInputInfo,128.507105,128.507105,11.433579,11.433579,USER32,[unknown],0
    @

    and in this stack trace i see heavy calling to QSettings::allKeys coming from QtCore4 i dont call QSettings::allKeys

    and then i have :

    @QPixmap::alphaChannel,1.159998,140.493087,0.103208,12.499999,QtGuid4,[unknown],0@

    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?


  • Moderators

    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?


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.