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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
#include <QTest>
#include <QSemaphore>
#include <qcoreapplication.h>
#include <qmutex.h>
#include <qthread.h>
#include <qwaitcondition.h>
#include "qthreadonce.h"
#include <QtTest/private/qemulationdetector_p.h>
class tst_QThreadOnce : public QObject
{
Q_OBJECT
private slots:
void initTestCase();
void sameThread();
void sameThread_data();
void multipleThreads();
void nesting();
void reentering();
#ifndef QT_NO_EXCEPTIONS
void exception();
#endif
};
void tst_QThreadOnce::initTestCase()
{
if (QTestPrivate::isRunningArmOnX86())
QSKIP("Flaky on QEMU, QTBUG-94737");
}
class SingletonObject: public QObject
{
Q_OBJECT
public:
static int runCount;
SingletonObject() { val.storeRelaxed(42); ++runCount; }
~SingletonObject() { }
QBasicAtomicInt val;
};
class IncrementThread: public QThread
{
public:
static QBasicAtomicInt runCount;
static QSingleton<SingletonObject> singleton;
QSemaphore &sem1, &sem2;
int &var;
IncrementThread(QSemaphore *psem1, QSemaphore *psem2, int *pvar, QObject *parent)
: QThread(parent), sem1(*psem1), sem2(*psem2), var(*pvar)
{ start(); }
~IncrementThread() { wait(); }
protected:
void run() override
{
sem2.release();
sem1.acquire(); // synchronize
Q_ONCE {
++var;
}
runCount.ref();
singleton->val.ref();
}
};
int SingletonObject::runCount = 0;
QBasicAtomicInt IncrementThread::runCount = Q_BASIC_ATOMIC_INITIALIZER(0);
QSingleton<SingletonObject> IncrementThread::singleton;
void tst_QThreadOnce::sameThread_data()
{
SingletonObject::runCount = 0;
QTest::addColumn<int>("expectedValue");
QTest::newRow("first") << 42;
QTest::newRow("second") << 43;
}
void tst_QThreadOnce::sameThread()
{
static int controlVariable = 0;
Q_ONCE {
QCOMPARE(controlVariable, 0);
++controlVariable;
}
QCOMPARE(controlVariable, 1);
static QSingleton<SingletonObject> s;
QTEST(int(s->val.loadRelaxed()), "expectedValue");
s->val.ref();
QCOMPARE(SingletonObject::runCount, 1);
}
void tst_QThreadOnce::multipleThreads()
{
#if defined(Q_OS_VXWORKS)
const int NumberOfThreads = 20;
#else
const int NumberOfThreads = 100;
#endif
int controlVariable = 0;
QSemaphore sem1, sem2(NumberOfThreads);
QObject *parent = new QObject;
for (int i = 0; i < NumberOfThreads; ++i)
new IncrementThread(&sem1, &sem2, &controlVariable, parent);
QCOMPARE(controlVariable, 0); // nothing must have set them yet
SingletonObject::runCount = 0;
IncrementThread::runCount.storeRelaxed(0);
// wait for all of them to be ready
sem2.acquire(NumberOfThreads);
// unleash the threads
sem1.release(NumberOfThreads);
// wait for all of them to terminate:
delete parent;
QCOMPARE(controlVariable, 1);
QCOMPARE(int(IncrementThread::runCount.loadRelaxed()), NumberOfThreads);
QCOMPARE(SingletonObject::runCount, 1);
}
void tst_QThreadOnce::nesting()
{
int variable = 0;
Q_ONCE {
Q_ONCE {
++variable;
}
}
QCOMPARE(variable, 1);
}
static void reentrant(int control, int &counter)
{
Q_ONCE {
if (counter)
reentrant(--control, counter);
++counter;
}
static QSingleton<SingletonObject> s;
s->val.ref();
}
void tst_QThreadOnce::reentering()
{
const int WantedRecursions = 5;
int count = 0;
SingletonObject::runCount = 0;
reentrant(WantedRecursions, count);
// reentrancy is undefined behavior:
QVERIFY(count == 1 || count == WantedRecursions);
QCOMPARE(SingletonObject::runCount, 1);
}
#if !defined(QT_NO_EXCEPTIONS)
static void exception_helper(int &val)
{
Q_ONCE {
if (val++ == 0) throw 0;
}
}
#endif
#ifndef QT_NO_EXCEPTIONS
void tst_QThreadOnce::exception()
{
int count = 0;
try {
exception_helper(count);
} catch (...) {
// nothing
}
QCOMPARE(count, 1);
try {
exception_helper(count);
} catch (...) {
QVERIFY2(false, "Exception shouldn't have been thrown...");
}
QCOMPARE(count, 2);
}
#endif
QTEST_MAIN(tst_QThreadOnce)
#include "tst_qthreadonce.moc"
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