From a3d8512fe167d838c4f6afbdd41a59ef913937ce Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Thu, 22 Dec 2022 11:36:04 +0100
Subject: [PATCH] Don't create a QRunnable in
 QAndroidApplication::runOnAndroidMainThread() w/o timeout

Creating a QRunnable is expensive business, incl. setting up
QThreadPool::globalInstance() if it wasn't set up already, so don't do
it for a no-op task.

Somewhat mitigates, but doesn't fix, QTBUG-109586.

Task-number: QTBUG-109586
Change-Id: If2043134414d68adc9188e5bb7650ca08046b4aa
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>
(cherry picked from commit 26ea6157e6429a6ba0794272df195c0bc591cda9)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/corelib/platform/android/qandroidnativeinterface.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/corelib/platform/android/qandroidnativeinterface.cpp b/src/corelib/platform/android/qandroidnativeinterface.cpp
index a93844139ba..6fb6bceadf7 100644
--- a/src/corelib/platform/android/qandroidnativeinterface.cpp
+++ b/src/corelib/platform/android/qandroidnativeinterface.cpp
@@ -159,8 +159,8 @@ QFuture<QVariant> QNativeInterface::QAndroidApplication::runOnAndroidMainThread(
     QFuture<QVariant> future = promise->future();
     promise->start();
 
-    (void) QtConcurrent::run([=, &future]() {
-        if (!timeout.isForever()) {
+    if (!timeout.isForever()) {
+        (void) QtConcurrent::run([=, &future]() {
             QEventLoop loop;
             QTimer::singleShot(timeout.remainingTime(), &loop, [&]() {
                 future.cancel();
@@ -177,8 +177,8 @@ QFuture<QVariant> QNativeInterface::QAndroidApplication::runOnAndroidMainThread(
             });
             watcher.setFuture(future);
             loop.exec();
-        }
-    });
+        });
+    }
 
     QMutexLocker locker(&g_pendingRunnablesMutex);
     g_pendingRunnables->push_back(std::pair(runnable, promise));