From 21c6fdf6a1cdf0603fab390fd2e85bd47d142fb5 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Tue, 5 Apr 2022 08:39:19 +0200
Subject: [PATCH] QMetaType: make all atomic operations explicit

In one case, optimize away an unnecessary extra load.

Task-number: QTBUG-103834
Change-Id: Iabbf58a09627dd2fd7a40c713a878d74cb522d60
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit f4b60a0850ea9f67338bfd22d0847f0f0db72255)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/corelib/kernel/qmetatype.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index 92ad38613b7..fc222ad9e8a 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -87,8 +87,9 @@ struct QMetaTypeCustomRegistry
 #endif
                     (ti->name);
             if (auto ti2 = aliases.value(name)) {
-                ti->typeId.storeRelaxed(ti2->typeId.loadRelaxed());
-                return ti2->typeId;
+                const auto id = ti2->typeId.loadRelaxed();
+                ti->typeId.storeRelaxed(id);
+                return id;
             }
             aliases[name] = ti;
             int size = registry.size();
@@ -2555,7 +2556,7 @@ static int qMetaTypeCustomType_unlocked(const char *typeName, int length)
         Q_ASSERT(!reg->lock.tryLockForWrite());
 #endif
         if (auto ti = reg->aliases.value(QByteArray::fromRawData(typeName, length), nullptr)) {
-            return ti->typeId;
+            return ti->typeId.loadRelaxed();
         }
     }
     return QMetaType::UnknownType;