Fix blocking UI when waiting start of the authorization fallback process

Instead of constantly checking (busy waiting) if the server was started,
perform the task in a local event loop.

Task-number: QTIFW-2374
Change-Id: I7ddf63014c0cf0a187085339a5394186b0245a63
Reviewed-by: Iikka Eklund <iikka.eklund@qt.io>
Reviewed-by: Katja Marttila <katja.marttila@qt.io>

1 files changed, 14 insertions, 5 deletions

diff --git a/src/libs/installer/remoteclient_p.h b/src/libs/installer/remoteclient_p.h
index 9cc679de8..e1809e0af 100644
--- a/src/libs/installer/remoteclient_p.h
+++ b/src/libs/installer/remoteclient_p.h
@@ -1,6 +1,6 @@
 /**************************************************************************
 **
-** Copyright (C) 2017 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the Qt Installer Framework.
@@ -39,7 +39,8 @@
 #include "constants.h"
 
 #include <QCoreApplication>
-#include <QElapsedTimer>
+#include <QDeadlineTimer>
+#include <QTimer>
 #include <QMutex>
 #include <QThread>
 
@@ -165,11 +166,19 @@ public:
         }
 
         if (started) {
-            QElapsedTimer t;
-            t.start();
+            QTimer timer;
+            QEventLoop loop;
             // 30 seconds waiting ought to be enough for the app to start
-            while ((!m_serverStarted) && (t.elapsed() < 30000))
+            QDeadlineTimer deadline(30000);
+
+            connect(&timer, &QTimer::timeout, [&]() {
                 m_serverStarted = authorize();
+                if (m_serverStarted || deadline.hasExpired())
+                    loop.quit();
+            });
+
+            timer.start(100);
+            loop.exec();
         }
     }