I am calling argon2 - memory intensive hashing function in Qt and measuring its running time:
...
QTime start = QTime::currentTime();
// call hashing function
QTime finish = QTime::currentTime();
time = start.msecsTo(finish) / 1000.0;
...
In argon2 library's test case, time is measured in another way:
...
clock_t start = clock();
// call hashing function
clock_t finish = clock();
time = ((double)finish - start) / CLOCKS_PER_SEC;
...
I am calling the function exactly as they call in their test case. But I am getting a twice bigger number (twice slower). Why? How to measure function running time in Qt? What clock() actually measures?
env:virtualBox, Ubuntu14.04 64bit, Qt5.2.1, Qt Creator 3.0.1.
You could also try to use the QElapsedTimer:
QElapsedTimer timer;
timer.start();
slowOperation1();
qDebug() << "The slow operation took" << timer.elapsed() << "milliseconds";
qDebug() << "The slow operation took" << timer.nsecsElapsed() << "nanoseconds";