qoperatingsystemversion_win: cache the retrieved version

Make it a static variable to avoid acquiring the system version multiple times. The system version won't change at runtime after all. Pick-to: 6.2 Change-Id: Ic381e5dd7b482fedc9c01242482559ffca9d3f2b Reviewed-by: Oliver Wolff <[email protected]>
sohide · Nov 2, 2021 · 3fe89ee · 3fe89ee
1 parent 059c48b
commit 3fe89ee
Showing 1 changed file with 8 additions and 6 deletions.
diff --git a/src/corelib/global/qoperatingsystemversion_win.cpp b/src/corelib/global/qoperatingsystemversion_win.cpp
@@ -110,12 +110,14 @@ OSVERSIONINFOEX qWindowsVersionInfo()
 
 QOperatingSystemVersion QOperatingSystemVersion::current()
 {
-    QOperatingSystemVersion v;
-    v.m_os = currentType();
-    const OSVERSIONINFOEX osv = qWindowsVersionInfo();
-    v.m_major = osv.dwMajorVersion;
-    v.m_minor = osv.dwMinorVersion;
-    v.m_micro = osv.dwBuildNumber;
+    static QOperatingSystemVersion v;
+    if (v.m_os == Unknown) {
+        v.m_os = currentType();
+        const OSVERSIONINFOEX osv = qWindowsVersionInfo();
+        v.m_major = osv.dwMajorVersion;
+        v.m_minor = osv.dwMinorVersion;
+        v.m_micro = osv.dwBuildNumber;
+    }
     return v;
 }