测试QT读写锁（QReadWriteLock ）和互斥锁（QReadWriteLock ）的执行效率

上代码：

#include <QCoreApplication>
#include <QElapsedTimer>
#include <QtConcurrent>
#include <QDebug>int main(int argc, char *argv[])
{QCoreApplication a(argc, argv);qSetMessagePattern("(%{time hh:mm:ss.zzz} %{threadid} %{file}:%{line}): \t%{message}");QList<int> list_report;for (int round = 0; round < 5; round++){QMutex *mtx_lock = new QMutex;QReadWriteLock *rw_lock = new QReadWriteLock;QFutureWatcher<void> *watcher = new QFutureWatcher<void>;QSemaphore semaphore;QAtomicInt times = 1000 * 1000; //1mQDateTime datatime;QElapsedTimer timer;timer.start();for (int i = 0; i < 5; i++){QFuture<void> future = QtConcurrent::run([&, i]() {int index = i;int write_times{0};semaphore.release(1);while (times > 0) {int type = QRandomGenerator::global()->bounded(2);if (type == 1 and index == 0) {
//                        QWriteLocker locker(rw_lock);
//                        datatime = QDateTime::currentDateTime();QMutexLocker locker(mtx_lock);datatime = QDateTime::currentDateTime();write_times++;} else {
//                        QReadLocker locker(rw_lock);
//                        auto newdata = datatime;QMutexLocker locker(mtx_lock);auto newdata = datatime;}times--;}qDebug()<<index<<"write:times"<<write_times;});watcher->setFuture(future);}semaphore.acquire(1);watcher->waitForFinished();qDebug() << round << "QFuture (ms)" << timer.elapsed()<<"------------------------------------";list_report.append(timer.elapsed());delete (watcher);delete (rw_lock);delete (mtx_lock);}qDebug()<<"report:"<<list_report;return a.exec();
}

测试结果 ：

5线程 （1000  * 1000）
锁	写概率	指定线程写	结果（单位:ms）	平均写入次数
读写锁	1/1000	否	(193, 191, 183, 188, 186)	200
互斥锁	1/1000	否	(111, 112, 109, 105, 106)	200
互斥锁	1/2	否	(2808, 2790, 2722, 2719, 2800)	100000
互斥锁	1/5	否	(1160, 1133, 1142, 1163, 1137)	40000
读写锁	1/5	否	(4627, 4689, 4614, 4524, 4617)	40000
互斥锁	1/2	是	(321, 303, 399, 358, 338)	50000
读写锁	1/2	是	(1406, 1387, 1412, 1388, 1412)	50000

小结：

读写锁QReadWriteLock 在指定线程写多个线程读，效率明显比多个线程同时读写好。

但是，都远低于互斥锁QMutex的执行效率。