QThreadPool: Protect the access to internal data with mutex

The class claims to be thread safe, however, when e.g.
one thread is calling setMaxThreadCount() and the second
is calling maxThreadCount() at the same time for the same thread pool
instance, the latter may receive rubbish data.
Protect all public setters/getters with a mutex.

Pick-to: 6.5 6.4
Change-Id: Ief29d017d4f80443fa1ae06f6b20872f07588768
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/corelib/thread/qthreadpool.cpp b/src/corelib/thread/qthreadpool.cpp
index a8a58fd12a..bb7e232f42 100644
--- a/src/corelib/thread/qthreadpool.cpp
+++ b/src/corelib/thread/qthreadpool.cpp
@@ -590,12 +590,14 @@ 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 +618,7 @@ void QThreadPool::setExpiryTimeout(int expiryTimeout)
 int QThreadPool::maxThreadCount() const
 {
     Q_D(const QThreadPool);
+    QMutexLocker locker(&d->mutex);
     return d->requestedMaxThreadCount;
 }
 
@@ -685,12 +688,14 @@ 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 +716,14 @@ 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;
 }