QTimer makes the application slow.

Fivestar

I made one application having one mainwindow and 7 dialogs.
Each dialog has some tasks to update data from oracle DB.
So I used QTimer on mainwindow such that

QTimer *timer = new QTimer(this);
connect(timer, SIGNAL(timeout()), mode2, SLOT(mode_update()));
connect(timer, SIGNAL(timeout()), mode3, SLOT(mode_update()));
connect(timer, SIGNAL(timeout()), mode4, SLOT(mode_update()));
connect(timer, SIGNAL(timeout()), mode5, SLOT(mode_update()));
connect(timer, SIGNAL(timeout()), mode6, SLOT(mode_update()));
connect(timer, SIGNAL(timeout()), mode7, SLOT(mode_update()));
timer->start(1000);

QTimer *timer10 = new QTimer(this);
connect(timer10, SIGNAL(timeout()), mode4, SLOT(mode_update10()));
connect(timer10, SIGNAL(timeout()), mode5, SLOT(mode_update10()));
connect(timer10, SIGNAL(timeout()), mode6, SLOT(mode_update10()));
timer->start(10000);

First, it works well, but, after 1 hour its update cycle delays to 15 second.
Is there any way to reduce delay?

mrjj

Hi
The delays comes from something.

Often is leaking memory .

So you should find out why it gets slow.
There is no reason using timers should become slow over time
so its something else.

muratkarakus7

Btw, maybe source of delay is data base connection. I suggest using a stopwatch to record total time spend for each slot. If time doesn't change over time but still you observe the delay, then use valgrind to check memory leaks.

http://doc.qt.io/qt-4.8/qt-demos-spectrum-3rdparty-fftreal-stopwatch-stopwatch-cpp.html