From 0627ab17277ad5fa83fe6fcab5af5cd2748162a3 Mon Sep 17 00:00:00 2001
From: Jarek Kobus <jaroslaw.kobus@qt.io>
Date: Mon, 20 Feb 2023 13:57:18 +0100
Subject: [PATCH] QThreadPool: Protect the access to internal data with mutex
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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>
---
 src/corelib/thread/qthreadpool.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/corelib/thread/qthreadpool.cpp b/src/corelib/thread/qthreadpool.cpp
index a8a58fd12a0..bb7e232f42e 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;
 }