From 92db806aa8e7c0c40b265e3cf584d4aa85fc3ba5 Mon Sep 17 00:00:00 2001
From: Lars Knoll <lars.knoll@qt.io>
Date: Mon, 14 Dec 2020 09:05:01 +0100
Subject: [PATCH] Update QMutexLocker documentation

And add an entry about the API changes to qt6-changed.qdoc.

Pick-to: 6.0
Task-number: QTBUG-89429
Change-Id: I146574acd3e4aa5ed6f1629fc68888f009472f19
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 .../doc/snippets/code/src_corelib_thread_qmutex.cpp      | 2 +-
 src/corelib/doc/src/qt6-changes.qdoc                     | 9 +++++++++
 src/corelib/thread/qmutex.cpp                            | 2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/corelib/doc/snippets/code/src_corelib_thread_qmutex.cpp b/src/corelib/doc/snippets/code/src_corelib_thread_qmutex.cpp
index 63897cabd4..020dc44eac 100644
--- a/src/corelib/doc/snippets/code/src_corelib_thread_qmutex.cpp
+++ b/src/corelib/doc/snippets/code/src_corelib_thread_qmutex.cpp
@@ -184,7 +184,7 @@ int complexFunction(int flag)
 class SignalWaiter
 {
 private:
-    QMutexLocker locker;
+    QMutexLocker<QMutex> locker;
 
 public:
     SignalWaiter(QMutex *mutex)
diff --git a/src/corelib/doc/src/qt6-changes.qdoc b/src/corelib/doc/src/qt6-changes.qdoc
index d789f42fc5..570dc45e93 100644
--- a/src/corelib/doc/src/qt6-changes.qdoc
+++ b/src/corelib/doc/src/qt6-changes.qdoc
@@ -392,6 +392,15 @@
         }
     \endcode
 
+    \section1 QMutex and Related Classes
+
+    In Qt 6, QRecursiveMutex does not inherit from QMutex anymore. This change was
+    done to improve the performance of both QMutex and QRecursiveMutex.
+
+    Due to those changes, the QMutex::RecursionMode enum has been removed, and
+    QMutexLocker is now a templated class that can operate on both QMutex and
+    QRecursiveMutex.
+
     \section1 QFuture and Related Classes
 
     \section2 QFuture
diff --git a/src/corelib/thread/qmutex.cpp b/src/corelib/thread/qmutex.cpp
index 4926eae2e9..702cf671cd 100644
--- a/src/corelib/thread/qmutex.cpp
+++ b/src/corelib/thread/qmutex.cpp
@@ -415,7 +415,7 @@ void QRecursiveMutex::unlock() noexcept
 
 
 /*!
-    \class QMutexLocker
+    \class template <typename Mutex> QMutexLocker
     \inmodule QtCore
     \brief The QMutexLocker class is a convenience class that simplifies
     locking and unlocking mutexes.