wasm: add asyncify manual test

Add simple QtCore-based test case which spins
a nested event loop.

Change-Id: Ia3a4ef76d561d0554faffcac8d36ae5dda2c6c53
Reviewed-by: Lorn Potter <lorn.potter@gmail.com>

tests/manual/wasm/eventloop/CMakeLists.txt

@@ -1,3 +1,4 @@
+add_subdirectory(asyncify_exec)
 add_subdirectory(main_exec)
 add_subdirectory(main_noexec)
 if(QT_FEATURE_widgets)

tests/manual/wasm/eventloop/asyncify_exec/CMakeLists.txt

@@ -0,0 +1,6 @@
+qt_internal_add_manual_test(asyncify_exec
+    SOURCES
+        main.cpp
+    PUBLIC_LIBRARIES
+        Qt::Core
+)

tests/manual/wasm/eventloop/asyncify_exec/main.cpp

@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include <QtCore>
+
+// This test shows how to asyncify enables blocking
+// the main thread on QEventLoop::exec(), while event
+// provessing continues.
+int main(int argc, char **argv)
+{
+    QCoreApplication app(argc, argv);
+
+#ifdef QT_HAVE_EMSCRIPTEN_ASYNCIFY
+    QTimer::singleShot(1000, []() {
+
+        QEventLoop loop;
+        QTimer::singleShot(2000, [&loop]() {
+            qDebug() << "Calling QEventLoop::quit()";
+            loop.quit();
+        });
+
+        qDebug() << "Calling QEventLoop::exec()";
+        loop.exec();
+        qDebug() << "Returned from QEventLoop::exec()";
+    });
+#else
+        qDebug() << "This test requires Emscripten asyncify. To enable,"
+                 << "configure Qt with -device-option QT_EMSCRIPTEN_ASYNCIFY=1";
+#endif
+
+    app.exec();
+}