[Qt-interest] Memory issues with painter->drawText() (shiva sitamraju)
Martin Hofius
Martin at hofius-online.com
Tue May 19 13:28:45 CEST 2009
Hi Shiva,
Am Dienstag, 19. Mai 2009 schrieb shiva sitamraju:
> Hi Martin,
>
> Thanks very much. I added
>
> Qt::WA_DeleteOnClose flag and the memory usage is not coming down.
I agree. In my test there is a memory block of about 4 MB occupied and remains
after closing the window. I guess that this is a c/c++ library issue and was
implemented to prevent countless memory allocation and release calls to the
operating system. This should be no problem if there is no memory leak...
Greetings
Martin
>
>
> Attaching the updated code.
>
>
> Thanks
>
> On Tue, May 19, 2009 at 3:30 PM, <qt-interest-request at trolltech.com> wrote:
> > Send Qt-interest mailing list submissions to
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> > Today's Topics:
> >
> > 1. Re: How the Qt-designer "Widget-Box" is developed. - Can I
> > see the source code for the same! (Tiago Correia)
> > 2. Memory issues with painter->drawText() (shiva sitamraju)
> > 3. Doubt in qInstallMsgHandler (Ravi Krishna)
> > 4. Re: Doubt in qInstallMsgHandler (Mohammed Sameer)
> >
> >
> > ---------- Forwarded message ----------
> > From: Tiago Correia <tiago at cnotinfor.pt>
> > To: "qt-interest at trolltech.com" <qt-interest at trolltech.com>
> > Date: Tue, 19 May 2009 09:25:34 +0100
> > Subject: Re: [Qt-interest] How the Qt-designer "Widget-Box" is developed.
> > - Can I see the source code for the same!
> > Hi,
> > The source code from QDesigner is available, in the folder
> > <QT Dir>/tools/designer/src/
> >
> > On Tue, May 19, 2009 at 6:37 AM, Santhosh Y <santhosh at softjin.com> wrote:
> >> Hi,
> >>
> >> Please find the attached file in which the Qt-Designer snapshot is
> >> shown. In widget Box which is highlighted in red in the attached
> >> document, "Layouts, Spacers, Buttons, Item Views" are in layout.
> >>
> >> How they developed this Widget Box, so that the underlying items having
> >> such layout so that, each item can be expanded or collapsed.
> >>
> >> Please help me or suggest me where to find the code for the same.
> >>
> >> Is the source code for developing Qt-designer is available?
> >>
> >> --
> >> ----------------------------------------------------
> >> Y Santhosh Kumar
> >> Senior Software Engineer
> >> SoftJin Technologies Private Limited
> >> Unit No. 102, Mobius Tower,
> >> I Floor, SJR I - Park,
> >> EPIP, White Field,
> >> Bangalore - 560066, India
> >> U : www.softjin.com
> >> E : santhosh at softjin.com
> >> T : +91-80-41779999
> >> M : +91-9740535265
> >> ----------------------------------------------------
> >>
> >>
> >>
> >> Business Disclaimer
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> >
> > ---------- Forwarded message ----------
> > From: shiva sitamraju <shivaenigma at gmail.com>
> > To: qt-interest at trolltech.com
> > Date: Tue, 19 May 2009 14:16:24 +0530
> > Subject: [Qt-interest] Memory issues with painter->drawText()
> > Hi everyone,
> >
> > Here is my issue. Whenever i call painter->drawText (with some newlines
> > in the text) the resident memory usage shoots up by around 10MB. Also to
> > add to the problems, the memory is not released when I close the widget.
> >
> > I am attaching the code to test this problem. I create a widget with a
> > pushbutton and on clicking the button I set a flag, due to which text is
> > drawn in paintEvent.
> >
> > After the paintEvent starts painting text the resident memory (res shown
> > in top) shoots up by around 10MB which is not released even after I close
> > the widget. Virtual memory usage also shoots up by a large number(around
> > 100MB) and is not reclaimed.
> >
> > I would be glad if someone can throw some insight on why this is
> > happening.
> >
> > Thanks
> > -Shiva
> >
> >
> > ---------- Forwarded message ----------
> > From: Ravi Krishna <ravik at softjin.com>
> > To: qt-interest at trolltech.com
> > Date: Tue, 19 May 2009 14:57:55 +0530
> > Subject: [Qt-interest] Doubt in qInstallMsgHandler
> > Hi,
> > When I run my QT application I am getting the following error
> > "QList: Out of Memory"
> > on stdout when the message handler is not set.
> >
> > To catch all the fatal error messages I set qInstallMsgHandler to
> > myMsgOut.
> >
> > void myMsgOut(QtMsgType type, const char *msg)
> > {
> > switch (type) {
> > case QtCriticalMsg:
> > std::cout << msg << std::endl;
> > break;
> > case QtFatalMsg:
> > std::cout << msg << std::endl;
> > QMessageBox::critical(NULL, "Fatal error", msg);
> > break;
> > default:
> > std::cout << msg << std::endl;
> > break;
> > }
> > }
> >
> > But after setting the message handler to myMsgOut, the application is
> > crashing, without giving any output. I wanted to know is there any
> > problem in my message handler function.
> >
> >
> > Regards,
> > Ravi krishna.M
> >
> >
> >
> > Business Disclaimer
> > ____________________________________________________________
> > This e-mail message and any files transmitted with it are intended solely
> > for the use of the individual or entity to which they are
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> >
> >
> >
> > ---------- Forwarded message ----------
> > From: Mohammed Sameer <msameer at foolab.org>
> > To: qt-interest at trolltech.com
> > Date: Tue, 19 May 2009 12:30:41 +0300
> > Subject: Re: [Qt-interest] Doubt in qInstallMsgHandler
> >
> > On Tue, May 19, 2009 at 02:57:55PM +0530, Ravi Krishna wrote:
> > > Hi,
> > > When I run my QT application I am getting the following error
> > > "QList: Out of Memory"
> > > on stdout when the message handler is not set.
> > >
> > > To catch all the fatal error messages I set qInstallMsgHandler to
> >
> > myMsgOut.
> >
> > > void myMsgOut(QtMsgType type, const char *msg)
> > > {
> > > switch (type) {
> > > case QtCriticalMsg:
> > > std::cout << msg << std::endl;
> > > break;
> > > case QtFatalMsg:
> > > std::cout << msg << std::endl;
> > > QMessageBox::critical(NULL, "Fatal error", msg);
> > > break;
> > > default:
> > > std::cout << msg << std::endl;
> > > break;
> > > }
> > > }
> > >
> > > But after setting the message handler to myMsgOut, the application is
> > > crashing, without giving any output. I wanted to know is there any
> > > problem in my message handler function.
> >
> > I don't know the reason for the crash but if it's an out of memory
> > condition then
> > I guess you should not create new widgets because it'll probably fail (No
> > memory) and if it
> > fails because of an out of memory condition then it might end up calling
> > your handler again
> > ... and so on ;-)
> >
> > Just my 0.02
> >
> >
> > Cheers,
> >
> > --
> > GPG-Key: 0xA3FD0DF7 - 9F73 032E EAC9 F7AD 951F 280E CB66 8E29 A3FD 0DF7
> > Debian User and Developer.
> > Homepage: www.foolab.org
> >
> >
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