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#include <QThread>

#include "../qfuture/versioncheck.h"

struct TestIterator

{

    TestIterator(int i)

    :i(i) { }

    int operator-(const TestIterator &other)

    {

        return i - other.i;

    }

    TestIterator& operator++()

    {

        ++i;

        return *this;

    }

    bool operator!=(const TestIterator &other) const

    {

        return i != other.i;

    }

    int i;

};

#include <qiterator.h>

#ifndef QT_NO_STL

namespace std {

template <>

struct iterator_traits<TestIterator>

{

    typedef random_access_iterator_tag iterator_category;

};

int distance(TestIterator &a, TestIterator &b)

{

    return b - a;

}

}

#endif

#include <qtconcurrentiteratekernel.h>

#include <QtTest/QtTest>

#ifndef QT_NO_CONCURRENT_TEST

using namespace QtConcurrent;

class tst_QtConcurrentIterateKernel: public QObject

{

    Q_OBJECT

private slots:

    // "for" iteration tests:

    void instantiate();

    void cancel();

    void stresstest();

    void noIterations();

    void throttling();

    void blockSize();

    void multipleResults();

#if 0

    //"while" iterations tests:

    void instantiateWhile();

    void stresstestWhile();

#endif

};

QAtomicInt iterations;

class PrintFor : public IterateKernel<TestIterator, void>

{

public:

    PrintFor(TestIterator begin, TestIterator end) : IterateKernel<TestIterator, void>(begin, end) {iterations = 0; }

    bool runIterations(TestIterator/*beginIterator*/, int begin, int end, void *)

    {

        iterations.fetchAndAddRelaxed(end - begin);

#ifdef PRINT

        qDebug() << QThread::currentThread() << "iteration" << begin <<  "to" << end << "(exclusive)";

#endif

        return false;

    }

    bool runIteration(TestIterator it, int index , void *result)

    { 

        return runIterations(it, index, index + 1, result);

    }

};

class SleepPrintFor : public IterateKernel<TestIterator, void>

{

public:

    SleepPrintFor(TestIterator begin, TestIterator end) : IterateKernel<TestIterator, void>(begin, end) {iterations = 0; }

    inline bool runIterations(TestIterator/*beginIterator*/, int begin, int end, void *)

    {

        QTest::qSleep(200);

        iterations.fetchAndAddRelaxed(end - begin);

#ifdef PRINT

        qDebug() << QThread::currentThread() << "iteration" << begin <<  "to" << end << "(exclusive)";

#endif

        return false;

    }

    bool runIteration(TestIterator it, int index , void *result)

    { 

        return runIterations(it, index, index + 1, result);

    }

};

void tst_QtConcurrentIterateKernel::instantiate()

{

    startThreadEngine(new PrintFor(0, 40)).startBlocking();

    QCOMPARE((int)iterations, 40);

}

void tst_QtConcurrentIterateKernel::cancel()

{

    {

        QFuture<void> f = startThreadEngine(new SleepPrintFor(0, 40)).startAsynchronously();

        f.cancel();

        f.waitForFinished();

        QVERIFY(f.isCanceled());

        QVERIFY(int(iterations) <= QThread::idealThreadCount()); // the threads might run one iteration each before they are canceled.

    }

}

QAtomicInt counter;

class CountFor : public IterateKernel<TestIterator, void>

{

public:

    CountFor(TestIterator begin, TestIterator end) : IterateKernel<TestIterator, void>(begin, end) {iterations = 0; }

    inline bool runIterations(TestIterator/*beginIterator*/, int begin, int end, void *)

    {

        counter.fetchAndAddRelaxed(end - begin);

        return false;

    }

    bool runIteration(TestIterator it, int index , void *result)

    { 

        return runIterations(it, index, index + 1, result);

    }

};

void tst_QtConcurrentIterateKernel::stresstest()

{

    const int iterations = 1000;

    const int times = 50;

    for (int i = 0; i < times; ++i) {

        counter = 0;

        CountFor f(0, iterations);

        f.startBlocking();

        QCOMPARE((int)counter, iterations);

    }

}

void tst_QtConcurrentIterateKernel::noIterations()

{

    const int times = 20000;

    for (int i = 0; i < times; ++i)

        startThreadEngine(new IterateKernel<TestIterator, void>(0, 0)).startBlocking();

}

QSet<QThread *> threads;

class ThrottleFor : public IterateKernel<TestIterator, void>

{

public:

    // this class throttles between iterations 100 and 200,

    // and then records how many threads that run between

    // iterations 140 and 160.

    ThrottleFor(TestIterator begin, TestIterator end) : IterateKernel<TestIterator, void>(begin, end) {iterations = 0; throttling = false; }

    inline bool runIterations(TestIterator/*beginIterator*/, int begin, int end, void *)

    {

        if (200 >= begin && 200 < end) {

            throttling = false;

        }

        iterations.fetchAndAddRelaxed(end - begin);

        QThread *thread = QThread::currentThread();

        if (begin > 140 && end < 160)

            threads.insert(thread);

        if (100 >= begin && 100 < end) {

            throttling = true;

        }

        QTest::qWait(1);

        return false;

    }

    bool runIteration(TestIterator it, int index , void *result)

    { 

        return runIterations(it, index, index + 1, result);

    }

    bool shouldThrottleThread()

    {

       return (iterations > 100 && iterations < 200);

    }

    bool throttling;

};

void tst_QtConcurrentIterateKernel::throttling()

{

    const int totalIterations = 400;

    iterations = 0;

    threads.clear();

    ThrottleFor f(0, totalIterations);

    f.startBlocking();

    QCOMPARE((int)iterations, totalIterations);

    QCOMPARE(threads.count(), 1);

}

int peakBlockSize = 0;

class BlockSizeRecorder : public IterateKernel<TestIterator, void>

{

public:

    BlockSizeRecorder(TestIterator begin, TestIterator end) : IterateKernel<TestIterator, void>(begin, end) { }

    inline bool runIterations(TestIterator, int begin, int end, void *)

    {

        peakBlockSize = qMax(peakBlockSize, end - begin);

        return false;

    }

};

void tst_QtConcurrentIterateKernel::blockSize()

{

#ifdef QT_NO_STL

    QSKIP("Missing stl iterators prevent correct block size calculation", SkipAll);

#endif

    const int expectedMinimumBlockSize = 1024 / QThread::idealThreadCount();

    BlockSizeRecorder(0, 10000).startBlocking();

    if (peakBlockSize < expectedMinimumBlockSize)

        qDebug() << "block size" << peakBlockSize;

    QVERIFY(peakBlockSize >= expectedMinimumBlockSize);

}

class MultipleResultsFor : public IterateKernel<TestIterator, int>

{

public:

    MultipleResultsFor(TestIterator begin, TestIterator end) : IterateKernel<TestIterator, int>(begin, end) { }

    inline bool runIterations(TestIterator, int begin, int end, int *results)

    {

        for (int i = begin; i < end; ++i)

            results[i - begin] = i;

        return true;

    }

};

void tst_QtConcurrentIterateKernel::multipleResults()

{

#ifdef QT_NO_STL

    QSKIP("Missing stl iterators prevent correct summation", SkipAll);

#endif

    QFuture<int> f = startThreadEngine(new MultipleResultsFor(0, 10)).startAsynchronously();

    QCOMPARE(f.results().count() , 10);

    QCOMPARE(f.resultAt(0), 0);

    QCOMPARE(f.resultAt(5), 5);

    QCOMPARE(f.resultAt(9), 9);

    f.waitForFinished();

}

#if 0

class PrintWhile : public IterateKernel<TestIterator, void>

{

public:

    PrintWhile() : IterateKernel<TestIterator, void>(0, 10, WhileIteration) { }

    bool runIteration(TestIterator it, TestIterator, void *)

    {

        return false;

    }

};

void tst_QtConcurrentIterateKernel::instantiateWhile()

{

    PrintWhile w;

    w.startBlocking();

}

QAtomicInt iterationCount;

class StressWhile : public IterateKernel<TestIterator, void>

{

public:

    StressWhile(TestIterator iterations) : IterateKernel<TestIterator, void>(0, iterations, WhileIteration) { }

    bool runIteration(TestIterator it, TestIterator index, void *)

    {

        if (it == index) // should match.

            ::iterationCount.ref();

        return false;

    }

};

void tst_QtConcurrentIterateKernel::stresstestWhile()

{

    int iterations = 100000;

    StressWhile w(iterations);

    w.startBlocking();

    QCOMPARE(int(iterationCount), iterations);

}

#endif

QTEST_MAIN(tst_QtConcurrentIterateKernel)

#include "tst_qtconcurrentiteratekernel.moc"

#else

QTEST_NOOP_MAIN

#endif