Short live QRecursiveMutex!

Move the recursive mutex use case out of QMutex into a separate class,
unsurprisingly called QRecursiveMutex. As an immediate benefit, 90% of
the QMutex users now enjoy a constexpr QMutex ctor.

This change prepares for a real split in Qt 6, so that both use-cases
are no longer bundled up in one class.

[ChangeLog][QtCore][QMutex] Added QRecursiveMutex as a replacement of
QMutex(QMutex::Recursive).

Change-Id: I79b8724e8a8ee65e4bd0f06acd76103fe4197b8c
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 5 insertions, 4 deletions

diff --git a/tests/auto/corelib/thread/qmutex/tst_qmutex.cpp b/tests/auto/corelib/thread/qmutex/tst_qmutex.cpp
index 37c5874c02..749aa45916 100644
--- a/tests/auto/corelib/thread/qmutex/tst_qmutex.cpp
+++ b/tests/auto/corelib/thread/qmutex/tst_qmutex.cpp
@@ -69,7 +69,8 @@ private slots:
 static const int iterations = 100;
 
 QAtomicInt lockCount(0);
-QMutex normalMutex, recursiveMutex(QMutex::Recursive);
+QMutex normalMutex;
+QRecursiveMutex recursiveMutex;
 QSemaphore testsTurn;
 QSemaphore threadsTurn;
 
@@ -993,9 +994,9 @@ public:
     QMutex mutex;
     QWaitCondition cond;
 
-    QMutex &test_mutex;
+    QRecursiveMutex &test_mutex;
 
-    inline rmutex_Thread(QMutex &m) : test_mutex(m) { }
+    inline rmutex_Thread(QRecursiveMutex &m) : test_mutex(m) { }
 
     void run()
     {
@@ -1024,7 +1025,7 @@ void tst_QMutex::lock_unlock_locked_tryLock()
     QMutex mutex;
     mutex_Thread thread(mutex);
 
-    QMutex rmutex(QMutex::Recursive);
+    QRecursiveMutex rmutex;
     rmutex_Thread rthread(rmutex);
 
     for (int i = 0; i < iterations; ++i) {