1 files changed, 28 insertions, 6 deletions

diff --git a/src/corelib/thread/qthreadpool.cpp b/src/corelib/thread/qthreadpool.cpp
index b1078dab18..51783321b9 100644
--- a/src/corelib/thread/qthreadpool.cpp
+++ b/src/corelib/thread/qthreadpool.cpp
@@ -188,7 +188,7 @@ inline bool comparePriority(int priority, const QueuePage *p)
 void QThreadPoolPrivate::enqueueTask(QRunnable *runnable, int priority)
 {
     Q_ASSERT(runnable != nullptr);
-    for (QueuePage *page : qAsConst(queue)) {
+    for (QueuePage *page : std::as_const(queue)) {
         if (page->priority() == priority && !page->isFull()) {
             page->push(runnable);
             return;
@@ -200,9 +200,9 @@ void QThreadPoolPrivate::enqueueTask(QRunnable *runnable, int priority)
 
 int QThreadPoolPrivate::activeThreadCount() const
 {
-    return (allThreads.count()
-            - expiredThreads.count()
-            - waitingThreads.count()
+    return (allThreads.size()
+            - expiredThreads.size()
+            - waitingThreads.size()
             + reservedThreads);
 }
 
@@ -269,7 +269,7 @@ void QThreadPoolPrivate::reset()
 
     mutex.unlock();
 
-    for (QThreadPoolThread *thread : qAsConst(allThreadsCopy)) {
+    for (QThreadPoolThread *thread : std::as_const(allThreadsCopy)) {
         if (thread->isRunning()) {
             thread->runnableReady.wakeAll();
             thread->wait();
@@ -348,7 +348,7 @@ bool QThreadPool::tryTake(QRunnable *runnable)
         return false;
 
     QMutexLocker locker(&d->mutex);
-    for (QueuePage *page : qAsConst(d->queue)) {
+    for (QueuePage *page : std::as_const(d->queue)) {
         if (page->tryTake(runnable)) {
             if (page->isFinished()) {
                 d->queue.removeOne(page);
@@ -475,6 +475,21 @@ QThreadPool *QThreadPool::globalInstance()
 }
 
 /*!
+    Returns the QThreadPool instance for Qt Gui.
+    \internal
+*/
+QThreadPool *QThreadPoolPrivate::qtGuiInstance()
+{
+    Q_CONSTINIT static QPointer<QThreadPool> guiInstance;
+    Q_CONSTINIT static QBasicMutex theMutex;
+
+    const QMutexLocker locker(&theMutex);
+    if (guiInstance.isNull() && !QCoreApplication::closingDown())
+        guiInstance = new QThreadPool();
+    return guiInstance;
+}
+
+/*!
     Reserves a thread and uses it to run \a runnable, unless this thread will
     make the current thread count exceed maxThreadCount().  In that case,
     \a runnable is added to a run queue instead. The \a priority argument can
@@ -590,12 +605,14 @@ bool QThreadPool::tryStart(std::function<void()> functionToRun)
 int QThreadPool::expiryTimeout() const
 {
     Q_D(const QThreadPool);
+    QMutexLocker locker(&d->mutex);
     return d->expiryTimeout;
 }
 
 void QThreadPool::setExpiryTimeout(int expiryTimeout)
 {
     Q_D(QThreadPool);
+    QMutexLocker locker(&d->mutex);
     if (d->expiryTimeout == expiryTimeout)
         return;
     d->expiryTimeout = expiryTimeout;
@@ -616,6 +633,7 @@ void QThreadPool::setExpiryTimeout(int expiryTimeout)
 int QThreadPool::maxThreadCount() const
 {
     Q_D(const QThreadPool);
+    QMutexLocker locker(&d->mutex);
     return d->requestedMaxThreadCount;
 }
 
@@ -685,12 +703,14 @@ void QThreadPool::reserveThread()
 void QThreadPool::setStackSize(uint stackSize)
 {
     Q_D(QThreadPool);
+    QMutexLocker locker(&d->mutex);
     d->stackSize = stackSize;
 }
 
 uint QThreadPool::stackSize() const
 {
     Q_D(const QThreadPool);
+    QMutexLocker locker(&d->mutex);
     return d->stackSize;
 }
 
@@ -711,12 +731,14 @@ uint QThreadPool::stackSize() const
 void QThreadPool::setThreadPriority(QThread::Priority priority)
 {
     Q_D(QThreadPool);
+    QMutexLocker locker(&d->mutex);
     d->threadPriority = priority;
 }
 
 QThread::Priority QThreadPool::threadPriority() const
 {
     Q_D(const QThreadPool);
+    QMutexLocker locker(&d->mutex);
     return d->threadPriority;
 }