[Qt-interest] QProcess output every five seconds ..

[chandrasekar wagmare]

if u are using linux system ..? if so try glxgears ..
    it will gives output of the system GL update performance every 5 sec ..
 here is the output
     4141 frames in 5.0 seconds = 828.175 FPS
4278 frames in 5.0 seconds = 855.514 FPS
4292 frames in 5.0 seconds = 858.278 FPS
4289 frames in 5.0 seconds = 857.783 FPS
4281 frames in 5.0 seconds = 856.154 FPS
4281 frames in 5.0 seconds = 856.113 FPS
4286 frames in 5.0 seconds = 857.108 FPS
4268 frames in 5.0 seconds = 853.481 FPS
4289 frames in 5.0 seconds = 857.796 FPS
4237 frames in 5.0 seconds = 847.388 FPS
4284 frames in 5.0 seconds = 856.748 FPS
4276 frames in 5.0 seconds = 855.032 FPS
4284 frames in 5.0 seconds = 856.781 FPS
4219 frames in 5.0 seconds = 843.677 FPS
4284 frames in 5.0 seconds = 856.639 FPS

each line will be printed in the console for every 5 seconds ...

 now i try QString prog = "glxgears";
               QStringList     args << "-display" <<"192.168.1.4:0.0" ;
graphicsProc = new QProcess();
graphicsProc->setProcessChannelMode(QProcess::MergedChannels);

connect(graphicsTestButton, SIGNAL(clicked()), this, SLOT(startProc()));

connect(graphicsProc, SIGNAL(readyReadStandardOutput()), this,
SLOT(readFromStdout()));

        connect(graphicsProc, SIGNAL(readyRead()), this,
SLOT(procUpdate()));

        connect(graphicsProc, SIGNAL(error(QProcess::ProcessError)),this,
SLOT(processError(QProcess::ProcessError)));

void GraphicsTestDialog::startProc()
{
        graphicsProc->start(prog, args);

}
void GraphicsTestDialog::readFromStdout()
{
        printf("the std out value \n");
        QTextCursor cursor(graphicsTextEdit->textCursor());
        cursor.movePosition(QTextCursor::Start);

        QProcess *pr = (QProcess*)sender();
        graphicsTextEdit->append(pr->readAllStandardOutput());
        graphicsTextEdit->setTextCursor(cursor);

}
void GraphicsTestDialog::processError(QProcess::ProcessError error)
{
        if (error == QProcess::FailedToStart) {
                graphicsTextEdit->append("failed to start the program .");
    }

}


now in output the slot readFromStdout() is called after 5 minutes not in
every 5 seconds ... even the signal SIGNAL(readyRead()) also called after 5
minutes only ....

after five minutes in graphicsTextEdit it is printing

4141 frames in 5.0 seconds = 828.175 FPS
4278 frames in 5.0 seconds = 855.514 FPS
4292 frames in 5.0 seconds = 858.278 FPS
4289 frames in 5.0 seconds = 857.783 FPS
4281 frames in 5.0 seconds = 856.154 FPS
4281 frames in 5.0 seconds = 856.113 FPS
4286 frames in 5.0 seconds = 857.108 FPS
4268 frames in 5.0 seconds = 853.481 FPS
4289 frames in 5.0 seconds = 857.796 FPS
4237 frames in 5.0 seconds = 847.388 FPS
4284 frames in 5.0 seconds = 856.748 FPS
4276 frames in 5.0 seconds = 855.032 FPS
4284 frames in 5.0 seconds = 856.781 FPS
4219 frames in 5.0 seconds = 843.677 FPS
4284 frames in 5.0 seconds = 856.639 FPS


and agin after 5 minutes it appending the same amount of text ....
   i dont know how to solve the problem .... please help ..




2009/3/24 Thiago Macieira <thiago.macieira at trolltech.com>

> chandrasekar wagmare wrote:
> >but the problem is after filling the entire buffer QProcess() calls the
> >readOut() slot ie the signal readyReadStandardOutput()  is emitted only
> >after the buffer fills otherwise it takes five minutes and printing it
> > in a heap ..
>
> Here's what I don't understand: QProcess's buffer doesn't have a limit, so
> it can't fill up. With that in mind, I have to ask: what exactly is the
> symptom? Your interpretation appears to be incorrect.
>
> --
> Thiago Macieira - thiago.macieira (AT) nokia.com
>  Senior Product Manager - Nokia, Qt Software
>      Sandakerveien 116, NO-0402 Oslo, Norway
>
> _______________________________________________
> Qt-interest mailing list
> Qt-interest at trolltech.com
> http://lists.trolltech.com/mailman/listinfo/qt-interest
>
>


-- 
CHANDRU
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.qt-project.org/pipermail/qt-interest-old/attachments/20090324/daedce42/attachment.html