Revision control
++ // Copyright (C) 2016 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++ #include <QtCore>
++
++ void slowOperation1()
++ {
++ static char buf[256];
++ for (int i = 0; i < (1<<20); ++i)
++ buf[i % sizeof buf] = i;
++ }
++
++ void slowOperation2(int) { slowOperation1(); }
++
++ void startExample()
++ {
++ //![0]
++ QElapsedTimer timer;
++ timer.start();
++
++ slowOperation1();
++
++ qDebug() << "The slow operation took" << timer.elapsed() << "milliseconds";
++ //![0]
++ }
++
++ //![1]
++ void executeSlowOperations(int timeout)
++ {
++ QElapsedTimer timer;
++ timer.start();
++ slowOperation1();
++
++ int remainingTime = timeout - timer.elapsed();
++ if (remainingTime > 0)
++ slowOperation2(remainingTime);
++ }
++ //![1]
++
++ //![2]
++ void executeOperationsForTime(int ms)
++ {
++ QElapsedTimer timer;
++ timer.start();
++
++ while (!timer.hasExpired(ms))
++ slowOperation1();
++ }
++ //![2]
++
++ int restartExample()
++ {
++ //![3]
++ QElapsedTimer timer;
++
++ int count = 1;
++ timer.start();
++ do {
++ count *= 2;
++ slowOperation2(count);
++ } while (timer.restart() < 250);
++
++ return count;
++ //![3]
++ }
++
++ int main(int argc, char **argv)
++ {
++ QCoreApplication app(argc, argv);
++
++ startExample();
++ restartExample();
++ executeSlowOperations(5);
++ executeOperationsForTime(5);
++ }