[Qt-interest] wait / sleep outside of QThread

[Matthias Pospiech]

I have long ago set up a function delay which is constantly looking for 
the elapsed time.

inline void delay(long ms)  //  time in ms
{
        QTime time;
        time.start();
        while (time.elapsed()<ms);       
}

This works fine, but is killing CPU usage for nothing. I can not use 
Signal/Slots, because that would mean a complete rewrite of most of my 
functions.
The typicall usage is something like

void foo()
{
    dowhatever();
    delay(100);
    donext();
}

or

while(ClassDerivedFromQThread.isRunning()) { delay(50); }



In this list I found some different approaches:

1) -------------------------------------

The sleep method of QThread is protected, but you can expose it like so:

class SleeperThread : public QThread
{
public:
static void msleep(unsigned long msecs)
{
QThread::msleep(msecs);
}
};

Then just call:
SleeperThread::msleep(1000);
from any thread.

2) -------------------------------------

#include <qwaitcondition.h>

QWaitCondition sleep;
sleep.wait(2000);   // two seconds

3) -------------------------------------

QTime dieTime = QTime::currentTime().addSecs(2);
while( QTime::currentTime() < dieTime )
	QCoreApplication::processEvents(QEventLoop::AllEvents, 100);


Is anything of this recommanded?

Matthias