RIP QBasicMutexLocker

This was used as a work-around for Q5MutexLocker's UB downcasting
QBasicMutex to QMutex, and for some unspecified performance
improvements.

Now that Q6MutexLocker is a template, the two are almost
token-by-token identical, so we can remove this work-around and use
QMutexLocker directly.

Partially reverts aea500d5d76864bb1a3918e338ca6806e1766e41.

Change-Id: I57ef5c53999869aa3454fbbaad884c1d18591b2a
Reviewed-by: Fabian Kosmale <[email protected]>
Reviewed-by: Thiago Macieira <[email protected]>
(cherry picked from commit 8d39b2165596f0aaae0e5841eb4c849cf4ee1bb0)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>

2 files changed, 12 insertions, 43 deletions

diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 137c1d8ac5a..d82f296cb66 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -234,7 +234,7 @@ bool QObjectPrivate::isSender(const QObject *receiver, const char *signal) const
     ConnectionData *cd = connections.loadRelaxed();
     if (signal_index < 0 || !cd)
         return false;
-    QBasicMutexLocker locker(signalSlotLock(q));
+    QMutexLocker locker(signalSlotLock(q));
     if (signal_index < cd->signalVectorCount()) {
         const QObjectPrivate::Connection *c = cd->signalVector.loadRelaxed()->at(signal_index).first.loadRelaxed();
 
@@ -274,7 +274,7 @@ QObjectList QObjectPrivate::senderList() const
     QObjectList returnValue;
     ConnectionData *cd = connections.loadRelaxed();
     if (cd) {
-        QBasicMutexLocker locker(signalSlotLock(q_func()));
+        QMutexLocker locker(signalSlotLock(q_func()));
         for (Connection *c = cd->senders; c; c = c->next)
             returnValue << c->sender;
     }
@@ -1025,7 +1025,7 @@ QObject::~QObject()
         }
 
         QBasicMutex *signalSlotMutex = signalSlotLock(this);
-        QBasicMutexLocker locker(signalSlotMutex);
+        QMutexLocker locker(signalSlotMutex);
 
         // disconnect all receivers
         int receiverCount = cd->signalVectorCount();
@@ -1383,7 +1383,7 @@ bool QObject::event(QEvent *e)
             QAbstractMetaCallEvent *mce = static_cast<QAbstractMetaCallEvent*>(e);
 
             if (!d_func()->connections.loadRelaxed()) {
-                QBasicMutexLocker locker(signalSlotLock(this));
+                QMutexLocker locker(signalSlotLock(this));
                 d_func()->ensureConnectionData();
             }
             QObjectPrivate::Sender sender(this, const_cast<QObject*>(mce->sender()), mce->signalId());
@@ -2537,7 +2537,7 @@ QObject *QObject::sender() const
 {
     Q_D(const QObject);
 
-    QBasicMutexLocker locker(signalSlotLock(this));
+    QMutexLocker locker(signalSlotLock(this));
     QObjectPrivate::ConnectionData *cd = d->connections.loadRelaxed();
     if (!cd || !cd->currentSender)
         return nullptr;
@@ -2579,7 +2579,7 @@ int QObject::senderSignalIndex() const
 {
     Q_D(const QObject);
 
-    QBasicMutexLocker locker(signalSlotLock(this));
+    QMutexLocker locker(signalSlotLock(this));
     QObjectPrivate::ConnectionData *cd = d->connections.loadRelaxed();
     if (!cd || !cd->currentSender)
         return -1;
@@ -2644,7 +2644,7 @@ int QObject::receivers(const char *signal) const
         }
 
         QObjectPrivate::ConnectionData *cd = d->connections.loadRelaxed();
-        QBasicMutexLocker locker(signalSlotLock(this));
+        QMutexLocker locker(signalSlotLock(this));
         if (cd && signal_index < cd->signalVectorCount()) {
             const QObjectPrivate::Connection *c = cd->signalVector.loadRelaxed()->at(signal_index).first.loadRelaxed();
             while (c) {
@@ -2691,7 +2691,7 @@ bool QObject::isSignalConnected(const QMetaMethod &signal) const
 
     signalIndex += QMetaObjectPrivate::signalOffset(signal.mobj);
 
-    QBasicMutexLocker locker(signalSlotLock(this));
+    QMutexLocker locker(signalSlotLock(this));
     return d->isSignalConnected(signalIndex, true);
 }
 
@@ -3597,7 +3597,7 @@ bool QMetaObjectPrivate::disconnect(const QObject *sender,
     QObject *s = const_cast<QObject *>(sender);
 
     QBasicMutex *senderMutex = signalSlotLock(sender);
-    QBasicMutexLocker locker(senderMutex);
+    QMutexLocker locker(senderMutex);
 
     QObjectPrivate::ConnectionData *scd = QObjectPrivate::get(s)->connections.loadRelaxed();
     if (!scd)
@@ -3824,7 +3824,7 @@ static void queued_activate(QObject *sender, int signal, QObjectPrivate::Connect
     while (argumentTypes[nargs - 1])
         ++nargs;
 
-    QBasicMutexLocker locker(signalSlotLock(c->receiver.loadRelaxed()));
+    QMutexLocker locker(signalSlotLock(c->receiver.loadRelaxed()));
     QObject *receiver = c->receiver.loadRelaxed();
     if (!receiver) {
         // the connection has been disconnected before we got the lock
@@ -3965,7 +3965,7 @@ void doActivate(QObject *sender, int signal_index, void **argv)
 
                 QSemaphore semaphore;
                 {
-                    QBasicMutexLocker locker(signalSlotLock(receiver));
+                    QMutexLocker locker(signalSlotLock(receiver));
                     if (!c->isSingleShot && !c->receiver.loadAcquire())
                         continue;
                     QMetaCallEvent *ev = c->isSlotObject ?
@@ -4270,7 +4270,7 @@ void QObject::dumpObjectInfo() const
            objectName().isEmpty() ? "unnamed" : objectName().toLocal8Bit().data());
 
     Q_D(const QObject);
-    QBasicMutexLocker locker(signalSlotLock(this));
+    QMutexLocker locker(signalSlotLock(this));
 
     // first, look for connections where this object is the sender
     qDebug("  SIGNALS OUT");
diff --git a/src/corelib/thread/qorderedmutexlocker_p.h b/src/corelib/thread/qorderedmutexlocker_p.h
index 730ba612731..68c33e499c8 100644
--- a/src/corelib/thread/qorderedmutexlocker_p.h
+++ b/src/corelib/thread/qorderedmutexlocker_p.h
@@ -116,35 +116,6 @@ private:
     bool locked;
 };
 
-class QBasicMutexLocker
-{
-public:
-    inline explicit QBasicMutexLocker(QBasicMutex *m) QT_MUTEX_LOCK_NOEXCEPT
-        : m(m), isLocked(true)
-    {
-        m->lock();
-    }
-    inline ~QBasicMutexLocker() { if (isLocked) unlock(); }
-
-    inline void unlock() noexcept
-    {
-        isLocked = false;
-        m->unlock();
-    }
-
-    inline void relock() QT_MUTEX_LOCK_NOEXCEPT
-    {
-        isLocked = true;
-        m->lock();
-    }
-
-private:
-    Q_DISABLE_COPY(QBasicMutexLocker)
-
-    QBasicMutex *m;
-    bool isLocked;
-};
-
 #else
 
 class QOrderedMutexLocker
@@ -163,8 +134,6 @@ public:
     static bool relock(QBasicMutex *, QBasicMutex *) { return false; }
 };
 
-using QBasicMutexLocker = QMutexLocker<QBasicMutex>;
-
 #endif