[Qt-interest] Overhead considerations: QObject::startTimer(), QTimer, QBasicTimer

[Mihail Naydenov]

----- Original Message -----
> From: Pritam Ghanghas <pritam_ghanghas at infosys.com>
> To: "qt-interest at qt.nokia.com" <qt-interest at qt.nokia.com>
> Cc: 
> Sent: Tuesday, September 13, 2011 2:54 PM
> Subject: [Qt-interest] Overhead considerations: QObject::startTimer(), QTimer, QBasicTimer
> 
> Hi All,
> 
> I need to use a lot of timers in my application. There are three
> approaches to timer in qt. I looked at documentation and couldn't 
> anything that compares their performance or overhead figures.
> 
> 
> QObject::startTimer(), QBasicTimer look very similar in functionality.
> QTimer is easy and neat to use but comes with QObject overhead. I was
> wondering "how much is this overhead? and are there other overheads to
> using QTimer instead of the other two?" 
> 

Depends on your use case.
If you need timely called slots - use a QTimer and connect to it's timeout.(The overhead is creating addition QObject and calling a slot - not much.)
If you need to call some generic code, most often already part of a QObject (access to members etc) - use the QBasicTimer and reimpl. QTimerEvent in that object.(No overhead, compared to the QTimer, which has to do the same thing behind the scenes.)

MihailNaydenov

> 
> Thanks,
> Pritam
> 
> 
> **************** CAUTION - Disclaimer *****************
> This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely 
> for the use of the addressee(s). If you are not the intended recipient, please 
> notify the sender by e-mail and delete the original message. Further, you are 
> not 
> to copy, disclose, or distribute this e-mail or its contents to any other person 
> and 
> any such actions are unlawful. This e-mail may contain viruses. Infosys has 
> taken 
> every reasonable precaution to minimize this risk, but is not liable for any 
> damage 
> you may sustain as a result of any virus in this e-mail. You should carry out 
> your 
> own virus checks before opening the e-mail or attachment. Infosys reserves the 
> right to monitor and review the content of all messages sent to or from this 
> e-mail 
> address. Messages sent to or from this e-mail address may be stored on the 
> Infosys e-mail system.
> ***INFOSYS******** End of Disclaimer ********INFOSYS***
> _______________________________________________
> Qt-interest mailing list
> Qt-interest at qt.nokia.com
> http://lists.qt.nokia.com/mailman/listinfo/qt-interest
>