Merge remote-tracking branch 'origin/5.10' into dev

 Conflicts:
	src/plugins/platforms/windows/qwindowsmousehandler.cpp
	src/plugins/platforms/xcb/qxcbimage.cpp
	tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp
	tests/manual/qtabletevent/regular_widgets/main.cpp

Done-with: Friedemann Kleint<Friedemann.Kleint@qt.io>
Done-with: Mårten Nordheim<marten.nordheim@qt.io>
Change-Id: I5b2499513a92c590ed0756f7d2e93c35a64b7f30

13 files changed, 210 insertions, 66 deletions

diff --git a/src/corelib/corelib.pro b/src/corelib/corelib.pro
index 3ab7794f2e..4d67e5837f 100644
--- a/src/corelib/corelib.pro
+++ b/src/corelib/corelib.pro
@@ -48,8 +48,6 @@ win32 {
     mingw {
         # otherwise mingw headers do not declare common functions like putenv
         CONFIG -= strict_c++
-        # Override MinGW's definition in _mingw.h
-        DEFINES += WINVER=0x600 _WIN32_WINNT=0x0600
     }
     LIBS_PRIVATE += -lws2_32
     !winrt {
diff --git a/src/corelib/global/global.pri b/src/corelib/global/global.pri
index 78b37755a4..7c31df4d6a 100644
--- a/src/corelib/global/global.pri
+++ b/src/corelib/global/global.pri
@@ -99,16 +99,13 @@ gcc:ltcg {
     SOURCES += $$VERSIONTAGGING_SOURCES
 }
 
-# On AARCH64 the fp16 extension is mandatory, so we don't need the conversion tables.
-!contains(QT_ARCH, "arm64") {
-    QMAKE_QFLOAT16_TABLES_GENERATE = global/qfloat16.h
-
-    qtPrepareTool(QMAKE_QFLOAT16_TABLES, qfloat16-tables)
-
-    qfloat16_tables.commands = $$QMAKE_QFLOAT16_TABLES ${QMAKE_FILE_OUT}
-    qfloat16_tables.output = global/qfloat16tables.cpp
-    qfloat16_tables.depends = $$QMAKE_QFLOAT16_TABLES
-    qfloat16_tables.input = QMAKE_QFLOAT16_TABLES_GENERATE
-    qfloat16_tables.variable_out = SOURCES
-    QMAKE_EXTRA_COMPILERS += qfloat16_tables
-}
+QMAKE_QFLOAT16_TABLES_GENERATE = global/qfloat16.h
+
+qtPrepareTool(QMAKE_QFLOAT16_TABLES, qfloat16-tables)
+
+qfloat16_tables.commands = $$QMAKE_QFLOAT16_TABLES ${QMAKE_FILE_OUT}
+qfloat16_tables.output = global/qfloat16tables.cpp
+qfloat16_tables.depends = $$QMAKE_QFLOAT16_TABLES
+qfloat16_tables.input = QMAKE_QFLOAT16_TABLES_GENERATE
+qfloat16_tables.variable_out = SOURCES
+QMAKE_EXTRA_COMPILERS += qfloat16_tables
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index f2f807e1d9..36b7560398 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -4296,6 +4296,7 @@ bool QInternal::activateCallbacks(Callback cb, void **parameters)
 /*!
     \macro qDebug(const char *message, ...)
     \relates <QtGlobal>
+    \threadsafe
 
     Calls the message handler with the debug message \a message. If no
     message handler has been installed, the message is printed to
@@ -4332,6 +4333,7 @@ bool QInternal::activateCallbacks(Callback cb, void **parameters)
 /*!
     \macro qInfo(const char *message, ...)
     \relates <QtGlobal>
+    \threadsafe
     \since 5.5
 
     Calls the message handler with the informational message \a message. If no
@@ -4369,6 +4371,7 @@ bool QInternal::activateCallbacks(Callback cb, void **parameters)
 /*!
     \macro qWarning(const char *message, ...)
     \relates <QtGlobal>
+    \threadsafe
 
     Calls the message handler with the warning message \a message. If no
     message handler has been installed, the message is printed to
@@ -4406,6 +4409,7 @@ bool QInternal::activateCallbacks(Callback cb, void **parameters)
 /*!
     \macro qCritical(const char *message, ...)
     \relates <QtGlobal>
+    \threadsafe
 
     Calls the message handler with the critical message \a message. If no
     message handler has been installed, the message is printed to
diff --git a/src/corelib/global/qrandom.cpp b/src/corelib/global/qrandom.cpp
index d77ec8075a..9abb9ece7f 100644
--- a/src/corelib/global/qrandom.cpp
+++ b/src/corelib/global/qrandom.cpp
@@ -154,15 +154,19 @@ class SystemRandom
 {
     static QBasicAtomicInt s_fdp1;  // "file descriptor plus 1"
     static int openDevice();
+#ifdef Q_CC_GNU
+     // If it's not GCC or GCC-like, then we'll leak the file descriptor
+    __attribute__((destructor))
+#endif
+    static void closeDevice();
     SystemRandom() {}
-    ~SystemRandom();
 public:
     enum { EfficientBufferFill = true };
     static qssize_t fillBuffer(void *buffer, qssize_t count);
 };
 QBasicAtomicInt SystemRandom::s_fdp1 = Q_BASIC_ATOMIC_INITIALIZER(0);
 
-SystemRandom::~SystemRandom()
+void SystemRandom::closeDevice()
 {
     int fd = s_fdp1.loadAcquire() - 1;
     if (fd >= 0)
diff --git a/src/corelib/global/qrandom.h b/src/corelib/global/qrandom.h
index 7f96cd6749..2259f2657a 100644
--- a/src/corelib/global/qrandom.h
+++ b/src/corelib/global/qrandom.h
@@ -62,8 +62,16 @@ public:
     static Q_CORE_EXPORT quint64 generate64();
     static double generateDouble()
     {
-        // use get64() to get enough bits
-        return double(generate64()) / ((std::numeric_limits<quint64>::max)() + double(1.0));
+        // IEEE 754 double precision has:
+        //   1 bit      sign
+        //  10 bits     exponent
+        //  53 bits     mantissa
+        // In order for our result to be normalized in the range [0, 1), we
+        // need exactly 53 bits of random data. Use generate64() to get enough.
+        quint64 x = generate64();
+        quint64 limit = Q_UINT64_C(1) << std::numeric_limits<double>::digits;
+        x >>= std::numeric_limits<quint64>::digits - std::numeric_limits<double>::digits;
+        return double(x) / double(limit);
     }
 
     static qreal bounded(qreal sup)
diff --git a/src/corelib/global/qt_windows.h b/src/corelib/global/qt_windows.h
index bc48104edc..67ba27f072 100644
--- a/src/corelib/global/qt_windows.h
+++ b/src/corelib/global/qt_windows.h
@@ -48,10 +48,10 @@
 #if defined(Q_CC_MINGW)
 // mingw's windows.h does not set _WIN32_WINNT, resulting breaking compilation
 #  ifndef WINVER
-#    define WINVER 0x600
+#    define WINVER 0x601
 #  endif
 #  ifndef _WIN32_WINNT
-#    define _WIN32_WINNT 0x600
+#    define _WIN32_WINNT 0x601
 #  endif
 #  ifndef NTDDI_VERSION
 #    define NTDDI_VERSION 0x06000000
diff --git a/src/corelib/io/qfilesystemengine_win.cpp b/src/corelib/io/qfilesystemengine_win.cpp
index 35ddb41215..944ca232ee 100644
--- a/src/corelib/io/qfilesystemengine_win.cpp
+++ b/src/corelib/io/qfilesystemengine_win.cpp
@@ -595,6 +595,9 @@ QByteArray QFileSystemEngine::id(const QFileSystemEntry &entry)
     params.dwSize = sizeof(params);
     params.dwFileAttributes = FILE_ATTRIBUTE_NORMAL;
     params.dwFileFlags = FILE_FLAG_BACKUP_SEMANTICS;
+    params.dwSecurityQosFlags = SECURITY_ANONYMOUS;
+    params.lpSecurityAttributes = NULL;
+    params.hTemplateFile = NULL;
     const HANDLE handle =
         CreateFile2((const wchar_t*)entry.nativeFilePath().utf16(), 0,
                     FILE_SHARE_READ, OPEN_EXISTING, &params);
diff --git a/src/corelib/io/qloggingcategory.cpp b/src/corelib/io/qloggingcategory.cpp
index 4256d4b6e1..b029274329 100644
--- a/src/corelib/io/qloggingcategory.cpp
+++ b/src/corelib/io/qloggingcategory.cpp
@@ -445,6 +445,7 @@ void QLoggingCategory::setFilterRules(const QString &rules)
 /*!
     \macro qCDebug(category)
     \relates QLoggingCategory
+    \threadsafe
     \since 5.2
 
     Returns an output stream for debug messages in the logging category
@@ -469,6 +470,7 @@ void QLoggingCategory::setFilterRules(const QString &rules)
 /*!
     \macro qCDebug(category, const char *message, ...)
     \relates QLoggingCategory
+    \threadsafe
     \since 5.3
 
     Logs a debug message \a message in the logging category \a category.
@@ -490,6 +492,7 @@ void QLoggingCategory::setFilterRules(const QString &rules)
 /*!
     \macro qCInfo(category)
     \relates QLoggingCategory
+    \threadsafe
     \since 5.5
 
     Returns an output stream for informational messages in the logging category
@@ -514,6 +517,7 @@ void QLoggingCategory::setFilterRules(const QString &rules)
 /*!
     \macro qCInfo(category, const char *message, ...)
     \relates QLoggingCategory
+    \threadsafe
     \since 5.5
 
     Logs an informational message \a message in the logging category \a category.
@@ -535,6 +539,7 @@ void QLoggingCategory::setFilterRules(const QString &rules)
 /*!
     \macro qCWarning(category)
     \relates QLoggingCategory
+    \threadsafe
     \since 5.2
 
     Returns an output stream for warning messages in the logging category
@@ -559,6 +564,7 @@ void QLoggingCategory::setFilterRules(const QString &rules)
 /*!
     \macro qCWarning(category, const char *message, ...)
     \relates QLoggingCategory
+    \threadsafe
     \since 5.3
 
     Logs a warning message \a message in the logging category \a category.
@@ -580,6 +586,7 @@ void QLoggingCategory::setFilterRules(const QString &rules)
 /*!
     \macro qCCritical(category)
     \relates QLoggingCategory
+    \threadsafe
     \since 5.2
 
     Returns an output stream for critical messages in the logging category
@@ -604,6 +611,7 @@ void QLoggingCategory::setFilterRules(const QString &rules)
 /*!
     \macro qCCritical(category, const char *message, ...)
     \relates QLoggingCategory
+    \threadsafe
     \since 5.3
 
     Logs a critical message \a message in the logging category \a category.
diff --git a/src/corelib/io/qurl.cpp b/src/corelib/io/qurl.cpp
index ac694a464a..a499dc2d30 100644
--- a/src/corelib/io/qurl.cpp
+++ b/src/corelib/io/qurl.cpp
@@ -499,9 +499,10 @@ public:
 
         InvalidFragmentError = Fragment << 8,
 
-        // the following two cases are only possible in combination
-        // with presence/absence of the authority and scheme. See validityError().
+        // the following three cases are only possible in combination with
+        // presence/absence of the path, authority and scheme. See validityError().
         AuthorityPresentAndPathIsRelative = Authority << 8 | Path << 8 | 0x10000,
+        AuthorityAbsentAndPathIsDoubleSlash,
         RelativeUrlPathContainsColonBeforeSlash = Scheme << 8 | Authority << 8 | Path << 8 | 0x10000,
 
         NoError = 0
@@ -1627,19 +1628,32 @@ inline QUrlPrivate::ErrorCode QUrlPrivate::validityError(QString *source, int *p
         return error->code;
     }
 
-    // There are two more cases of invalid URLs that QUrl recognizes and they
+    // There are three more cases of invalid URLs that QUrl recognizes and they
     // are only possible with constructed URLs (setXXX methods), not with
     // parsing. Therefore, they are tested here.
     //
-    // The two cases are a non-empty path that doesn't start with a slash and:
+    // Two cases are a non-empty path that doesn't start with a slash and:
     //  - with an authority
     //  - without an authority, without scheme but the path with a colon before
     //    the first slash
+    // The third case is an empty authority and a non-empty path that starts
+    // with "//".
     // Those cases are considered invalid because toString() would produce a URL
     // that wouldn't be parsed back to the same QUrl.
 
-    if (path.isEmpty() || path.at(0) == QLatin1Char('/'))
+    if (path.isEmpty())
         return NoError;
+    if (path.at(0) == QLatin1Char('/')) {
+        if (sectionIsPresent & QUrlPrivate::Authority || port != -1 ||
+                path.length() == 1 || path.at(1) != QLatin1Char('/'))
+            return NoError;
+        if (source) {
+            *source = path;
+            *position = 0;
+        }
+        return AuthorityAbsentAndPathIsDoubleSlash;
+    }
+
     if (sectionIsPresent & QUrlPrivate::Host) {
         if (source) {
             *source = path;
@@ -2514,10 +2528,7 @@ void QUrl::setPath(const QString &path, ParsingMode mode)
         mode = TolerantMode;
     }
 
-    int from = 0;
-    while (from < data.length() - 2 && data.midRef(from, 2) == QLatin1String("//"))
-        ++from;
-    d->setPath(data, from, data.length());
+    d->setPath(data, 0, data.length());
 
     // optimized out, since there is no path delimiter
 //    if (path.isNull())
@@ -3989,6 +4000,8 @@ static QString errorMessage(QUrlPrivate::ErrorCode errorCode, const QString &err
 
     case QUrlPrivate::AuthorityPresentAndPathIsRelative:
         return QStringLiteral("Path component is relative and authority is present");
+    case QUrlPrivate::AuthorityAbsentAndPathIsDoubleSlash:
+        return QStringLiteral("Path component starts with '//' and authority is absent");
     case QUrlPrivate::RelativeUrlPathContainsColonBeforeSlash:
         return QStringLiteral("Relative URL's path component contains ':' before any '/'");
     }
diff --git a/src/corelib/kernel/qcoreevent.cpp b/src/corelib/kernel/qcoreevent.cpp
index e90cd842ab..1e6b328c75 100644
--- a/src/corelib/kernel/qcoreevent.cpp
+++ b/src/corelib/kernel/qcoreevent.cpp
@@ -170,10 +170,10 @@ QT_BEGIN_NAMESPACE
     \value LeaveEditFocus                   An editor widget loses focus for editing. QT_KEYPAD_NAVIGATION must be defined.
     \value LeaveWhatsThisMode               Send to toplevel widgets when the application leaves "What's This?" mode.
     \value LocaleChange                     The system locale has changed.
-    \value NonClientAreaMouseButtonDblClick A mouse double click occurred outside the client area.
-    \value NonClientAreaMouseButtonPress    A mouse button press occurred outside the client area.
-    \value NonClientAreaMouseButtonRelease  A mouse button release occurred outside the client area.
-    \value NonClientAreaMouseMove           A mouse move occurred outside the client area.
+    \value NonClientAreaMouseButtonDblClick A mouse double click occurred outside the client area (QMouseEvent).
+    \value NonClientAreaMouseButtonPress    A mouse button press occurred outside the client area (QMouseEvent).
+    \value NonClientAreaMouseButtonRelease  A mouse button release occurred outside the client area (QMouseEvent).
+    \value NonClientAreaMouseMove           A mouse move occurred outside the client area (QMouseEvent).
     \value MacSizeChange                    The user changed his widget sizes (\macos only).
     \value MetaCall                         An asynchronous method invocation via QMetaObject::invokeMethod().
     \value ModifiedChange                   Widgets modification state has been changed.
diff --git a/src/corelib/thread/qmutex.h b/src/corelib/thread/qmutex.h
index f40dd3c814..541f6af546 100644
--- a/src/corelib/thread/qmutex.h
+++ b/src/corelib/thread/qmutex.h
@@ -251,7 +251,7 @@ class Q_CORE_EXPORT QMutex
 public:
     enum RecursionMode { NonRecursive, Recursive };
 
-    inline explicit QMutex(RecursionMode mode = NonRecursive) Q_DECL_NOTHROW { Q_UNUSED(mode); }
+    inline Q_DECL_CONSTEXPR explicit QMutex(RecursionMode = NonRecursive) Q_DECL_NOTHROW { }
 
     inline void lock() Q_DECL_NOTHROW {}
     inline bool tryLock(int timeout = 0) Q_DECL_NOTHROW { Q_UNUSED(timeout); return true; }
diff --git a/src/corelib/thread/qthreadpool.cpp b/src/corelib/thread/qthreadpool.cpp
index fd5a1106a0..157cbeaf4d 100644
--- a/src/corelib/thread/qthreadpool.cpp
+++ b/src/corelib/thread/qthreadpool.cpp
@@ -73,7 +73,7 @@ public:
     \internal
 */
 QThreadPoolThread::QThreadPoolThread(QThreadPoolPrivate *manager)
-    :manager(manager), runnable(0)
+    :manager(manager), runnable(nullptr)
 {
     setStackSize(manager->stackSize);
 }
@@ -86,7 +86,7 @@ void QThreadPoolThread::run()
     QMutexLocker locker(&manager->mutex);
     for(;;) {
         QRunnable *r = runnable;
-        runnable = 0;
+        runnable = nullptr;
 
         do {
             if (r) {
@@ -118,8 +118,19 @@ void QThreadPoolThread::run()
             if (manager->tooManyThreadsActive())
                 break;
 
-            r = !manager->queue.isEmpty() ? manager->queue.takeFirst().first : 0;
-        } while (r != 0);
+            if (manager->queue.isEmpty()) {
+                r = nullptr;
+                break;
+            }
+
+            QueuePage *page = manager->queue.first();
+            r = page->pop();
+
+            if (page->isFinished()) {
+                manager->queue.removeFirst();
+                delete page;
+            }
+        } while (true);
 
         if (manager->isExiting) {
             registerThreadInactive();
@@ -160,6 +171,7 @@ QThreadPoolPrivate:: QThreadPoolPrivate()
 
 bool QThreadPoolPrivate::tryStart(QRunnable *task)
 {
+    Q_ASSERT(task != nullptr);
     if (allThreads.isEmpty()) {
         // always create at least one thread
         startThread(task);
@@ -180,7 +192,7 @@ bool QThreadPoolPrivate::tryStart(QRunnable *task)
     if (!expiredThreads.isEmpty()) {
         // restart an expired thread
         QThreadPoolThread *thread = expiredThreads.dequeue();
-        Q_ASSERT(thread->runnable == 0);
+        Q_ASSERT(thread->runnable == nullptr);
 
         ++activeThreads;
 
@@ -196,22 +208,25 @@ bool QThreadPoolPrivate::tryStart(QRunnable *task)
     return true;
 }
 
-inline bool operator<(int priority, const QPair<QRunnable *, int> &p)
-{ return p.second < priority; }
-inline bool operator<(const QPair<QRunnable *, int> &p, int priority)
-{ return priority < p.second; }
+inline bool comparePriority(int priority, const QueuePage *p)
+{
+    return p->priority() < priority;
+}
 
 void QThreadPoolPrivate::enqueueTask(QRunnable *runnable, int priority)
 {
+    Q_ASSERT(runnable != nullptr);
     if (runnable->autoDelete())
         ++runnable->ref;
 
-    // put it on the queue
-    QVector<QPair<QRunnable *, int> >::const_iterator begin = queue.constBegin();
-    QVector<QPair<QRunnable *, int> >::const_iterator it = queue.constEnd();
-    if (it != begin && priority > (*(it - 1)).second)
-        it = std::upper_bound(begin, --it, priority);
-    queue.insert(it - begin, qMakePair(runnable, priority));
+    for (QueuePage *page : qAsConst(queue)) {
+        if (page->priority() == priority && !page->isFull()) {
+            page->push(runnable);
+            return;
+        }
+    }
+    auto it = std::upper_bound(queue.constBegin(), queue.constEnd(), priority, comparePriority);
+    queue.insert(std::distance(queue.constBegin(), it), new QueuePage(runnable, priority));
 }
 
 int QThreadPoolPrivate::activeThreadCount() const
@@ -225,8 +240,18 @@ int QThreadPoolPrivate::activeThreadCount() const
 void QThreadPoolPrivate::tryToStartMoreThreads()
 {
     // try to push tasks on the queue to any available threads
-    while (!queue.isEmpty() && tryStart(queue.constFirst().first))
-        queue.removeFirst();
+    while (!queue.isEmpty()) {
+        QueuePage *page = queue.first();
+        if (!tryStart(page->first()))
+            break;
+
+        page->pop();
+
+        if (page->isFinished()) {
+            queue.removeFirst();
+            delete page;
+        }
+    }
 }
 
 bool QThreadPoolPrivate::tooManyThreadsActive() const
@@ -240,6 +265,7 @@ bool QThreadPoolPrivate::tooManyThreadsActive() const
 */
 void QThreadPoolPrivate::startThread(QRunnable *runnable)
 {
+    Q_ASSERT(runnable != nullptr);
     QScopedPointer <QThreadPoolThread> thread(new QThreadPoolThread(this));
     thread->setObjectName(QLatin1String("Thread (pooled)"));
     Q_ASSERT(!allThreads.contains(thread.data())); // if this assert hits, we have an ABA problem (deleted threads don't get removed here)
@@ -303,12 +329,14 @@ bool QThreadPoolPrivate::waitForDone(int msecs)
 void QThreadPoolPrivate::clear()
 {
     QMutexLocker locker(&mutex);
-    for (QVector<QPair<QRunnable *, int> >::const_iterator it = queue.constBegin();
-         it != queue.constEnd(); ++it) {
-        QRunnable* r = it->first;
-        if (r->autoDelete() && !--r->ref)
-            delete r;
+    for (QueuePage *page : qAsConst(queue)) {
+        while (!page->isFinished()) {
+            QRunnable *r = page->pop();
+            if (r && r->autoDelete() && !--r->ref)
+                delete r;
+        }
     }
+    qDeleteAll(queue);
     queue.clear();
 }
 
@@ -333,22 +361,21 @@ bool QThreadPool::tryTake(QRunnable *runnable)
 {
     Q_D(QThreadPool);
 
-    if (runnable == 0)
+    if (runnable == nullptr)
         return false;
     {
         QMutexLocker locker(&d->mutex);
 
-        auto it = d->queue.begin();
-        auto end = d->queue.end();
-
-        while (it != end) {
-            if (it->first == runnable) {
-                d->queue.erase(it);
+        for (QueuePage *page : qAsConst(d->queue)) {
+            if (page->tryTake(runnable)) {
+                if (page->isFinished()) {
+                    d->queue.removeOne(page);
+                    delete page;
+                }
                 if (runnable->autoDelete())
                     --runnable->ref; // undo ++ref in start()
                 return true;
             }
-            ++it;
         }
     }
 
diff --git a/src/corelib/thread/qthreadpool_p.h b/src/corelib/thread/qthreadpool_p.h
index 8b6a8cc476..d03ba9d77f 100644
--- a/src/corelib/thread/qthreadpool_p.h
+++ b/src/corelib/thread/qthreadpool_p.h
@@ -63,6 +63,87 @@
 
 QT_BEGIN_NAMESPACE
 
+class QueuePage {
+public:
+    enum {
+        MaxPageSize = 256
+    };
+
+    QueuePage(QRunnable *runnable, int pri)
+        : m_priority(pri)
+    {
+        push(runnable);
+    }
+
+    bool isFull() {
+        return m_lastIndex >= MaxPageSize - 1;
+    }
+
+    bool isFinished() {
+        return m_firstIndex > m_lastIndex;
+    }
+
+    void push(QRunnable *runnable) {
+        Q_ASSERT(runnable != nullptr);
+        Q_ASSERT(!isFull());
+        m_lastIndex += 1;
+        m_entries[m_lastIndex] = runnable;
+    }
+
+    void skipToNextOrEnd() {
+        while (!isFinished() && m_entries[m_firstIndex] == nullptr) {
+            m_firstIndex += 1;
+        }
+    }
+
+    QRunnable *first() {
+        Q_ASSERT(!isFinished());
+        QRunnable *runnable = m_entries[m_firstIndex];
+        Q_ASSERT(runnable);
+        return runnable;
+    }
+
+    QRunnable *pop() {
+        Q_ASSERT(!isFinished());
+        QRunnable *runnable = first();
+        Q_ASSERT(runnable);
+
+        // clear the entry although this should not be necessary
+        m_entries[m_firstIndex] = nullptr;
+        m_firstIndex += 1;
+
+        // make sure the next runnable returned by first() is not a nullptr
+        skipToNextOrEnd();
+
+        return runnable;
+    }
+
+    bool tryTake(QRunnable *runnable) {
+        Q_ASSERT(!isFinished());
+        for (int i = m_firstIndex; i <= m_lastIndex; i++) {
+            if (m_entries[i] == runnable) {
+                m_entries[i] = nullptr;
+                if (i == m_firstIndex) {
+                    // make sure first() does not return a nullptr
+                    skipToNextOrEnd();
+                }
+                return true;
+            }
+        }
+        return false;
+    }
+
+    int priority() const {
+        return m_priority;
+    }
+
+private:
+    int m_priority = 0;
+    int m_firstIndex = 0;
+    int m_lastIndex = -1;
+    QRunnable *m_entries[MaxPageSize];
+};
+
 class QThreadPoolThread;
 class Q_CORE_EXPORT QThreadPoolPrivate : public QObjectPrivate
 {
@@ -84,12 +165,13 @@ public:
     bool waitForDone(int msecs);
     void clear();
     void stealAndRunRunnable(QRunnable *runnable);
+    void deletePageIfFinished(QueuePage *page);
 
     mutable QMutex mutex;
     QList<QThreadPoolThread *> allThreads;
     QQueue<QThreadPoolThread *> waitingThreads;
     QQueue<QThreadPoolThread *> expiredThreads;
-    QVector<QPair<QRunnable *, int> > queue;
+    QVector<QueuePage*> queue;
     QWaitCondition noActiveThreads;
 
     int expiryTimeout = 30000;