Port from implicit to explicit atomic integer operations

The old code used the implicit conversions from QAtomicInteger<T> to T
and vice versa. The semantics of these differ from the ones std::atomic
uses, so we're going to deprecate these, like we did for load() and
store(), too.

This patch fixex some users of these APIs before we deprecate them.

Change-Id: I4877276581757cd57e042efea8296fe535a493d1
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

4 files changed, 10 insertions, 8 deletions

diff --git a/src/corelib/global/qrandom.cpp b/src/corelib/global/qrandom.cpp
index 84cf960f2d..379e37ac07 100644
--- a/src/corelib/global/qrandom.cpp
+++ b/src/corelib/global/qrandom.cpp
@@ -359,17 +359,17 @@ Q_NEVER_INLINE void QRandomGenerator::SystemGenerator::generate(quint32 *begin,
     quint32 *buffer = begin;
     qsizetype count = end - begin;
 
-    if (Q_UNLIKELY(uint(qt_randomdevice_control) & SetRandomData)) {
-        uint value = uint(qt_randomdevice_control) & RandomDataMask;
+    if (Q_UNLIKELY(uint(qt_randomdevice_control.loadAcquire()) & SetRandomData)) {
+        uint value = uint(qt_randomdevice_control.loadAcquire()) & RandomDataMask;
         std::fill_n(buffer, count, value);
         return;
     }
 
     qsizetype filled = 0;
-    if (qt_has_hwrng() && (uint(qt_randomdevice_control) & SkipHWRNG) == 0)
+    if (qt_has_hwrng() && (uint(qt_randomdevice_control.loadAcquire()) & SkipHWRNG) == 0)
         filled += qt_random_cpu(buffer, count);
 
-    if (filled != count && (uint(qt_randomdevice_control) & SkipSystemRNG) == 0) {
+    if (filled != count && (uint(qt_randomdevice_control.loadAcquire()) & SkipSystemRNG) == 0) {
         qsizetype bytesFilled =
                 fillBuffer(buffer + filled, (count - filled) * qsizetype(sizeof(*buffer)));
         filled += bytesFilled / qsizetype(sizeof(*buffer));
@@ -1222,7 +1222,7 @@ void QRandomGenerator::_fillRange(void *buffer, void *bufferEnd)
     quint32 *begin = static_cast<quint32 *>(buffer);
     quint32 *end = static_cast<quint32 *>(bufferEnd);
 
-    if (type == SystemRNG || Q_UNLIKELY(uint(qt_randomdevice_control) & (UseSystemRNG|SetRandomData)))
+    if (type == SystemRNG || Q_UNLIKELY(uint(qt_randomdevice_control.loadAcquire()) & (UseSystemRNG|SetRandomData)))
         return SystemGenerator::self().generate(begin, end);
 
     SystemAndGlobalGenerators::PRNGLocker lock(this);
diff --git a/src/corelib/global/qrandom_p.h b/src/corelib/global/qrandom_p.h
index 917a91098e..167f4cc57d 100644
--- a/src/corelib/global/qrandom_p.h
+++ b/src/corelib/global/qrandom_p.h
@@ -76,7 +76,9 @@ Q_CORE_EXPORT QBasicAtomicInteger<uint> qt_randomdevice_control = Q_BASIC_ATOMIC
 #elif defined(QT_BUILD_INTERNAL)
 extern Q_CORE_EXPORT QBasicAtomicInteger<uint> qt_randomdevice_control;
 #else
-enum { qt_randomdevice_control = 0 };
+static const struct {
+    uint loadAcquire() const { return 0; }
+} qt_randomdevice_control;
 #endif
 
 inline bool qt_has_hwrng()
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 8f80be30bd..e3b25f8bf7 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -421,7 +421,7 @@ void QObjectPrivate::ConnectionData::cleanOrphanedConnectionsImpl(QObject *sende
     ConnectionOrSignalVector *c = nullptr;
     {
         QBasicMutexLocker l(signalSlotLock(sender));
-        if (ref > 1)
+        if (ref.loadAcquire() > 1)
             return;
 
         // Since ref == 1, no activate() is in process since we locked the mutex. That implies,
diff --git a/src/corelib/kernel/qobject_p.h b/src/corelib/kernel/qobject_p.h
index 1953aea21e..247c7b1501 100644
--- a/src/corelib/kernel/qobject_p.h
+++ b/src/corelib/kernel/qobject_p.h
@@ -279,7 +279,7 @@ public:
         void removeConnection(Connection *c);
         void cleanOrphanedConnections(QObject *sender)
         {
-            if (orphaned.loadRelaxed() && ref == 1)
+            if (orphaned.loadRelaxed() && ref.loadAcquire() == 1)
                 cleanOrphanedConnectionsImpl(sender);
         }
         void cleanOrphanedConnectionsImpl(QObject *sender);