corewlan: avoid unnecessary currentInterface.serviceActive checks

currentInterface.serviceActive is relatively expensive and causes
significant spikes in cpu load. Luckily, we can easily memorize
the result.

Change-Id: Ic7983b63bba5507bc1e34b0644e73365dc44f200
Task-number: QTBUG-45798
Task-number: QTCREATORBUG-15741
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@theqtcompany.com>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@theqtcompany.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@theqtcompany.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/plugins/bearer/corewlan/qcorewlanengine.mm b/src/plugins/bearer/corewlan/qcorewlanengine.mm
index 6d16b59d35..d89078465b 100644
--- a/src/plugins/bearer/corewlan/qcorewlanengine.mm
+++ b/src/plugins/bearer/corewlan/qcorewlanengine.mm
@@ -158,6 +158,7 @@ void QScanThread::run()
     mutex.lock();
     CWInterface *currentInterface = [CWInterface interfaceWithName: QCFString::toNSString(interfaceName)];
     mutex.unlock();
+    const bool currentInterfaceServiceActive = currentInterface.serviceActive;
 
     if (currentInterface.powerOn) {
         NSError *err = nil;
@@ -172,7 +173,7 @@ void QScanThread::run()
 
                 QNetworkConfiguration::StateFlags state = QNetworkConfiguration::Undefined;
                 bool known = isKnownSsid(networkSsid);
-                if (currentInterface.serviceActive) {
+                if (currentInterfaceServiceActive) {
                     if( networkSsid == QCFString::toQString( [currentInterface ssid])) {
                         state = QNetworkConfiguration::Active;
                     }
@@ -215,7 +216,7 @@ void QScanThread::run()
                 interfaceName = ij.value();
             }
 
-            if (currentInterface.serviceActive) {
+            if (currentInterfaceServiceActive) {
                 if( networkSsid == QCFString::toQString([currentInterface ssid])) {
                     state = QNetworkConfiguration::Active;
                 }