Revert "improve thread management"

This reverts commit 3f3b268916.

3rdparty/QThreadCreateThread.hpp

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <future>
+#include <QThread>
+
+// FOR OLD QT
+
+class QThreadCreateThread : public QThread {
+public:
+    explicit QThreadCreateThread(std::future<void> &&future)
+            : m_future(std::move(future)) {
+        // deleteLater
+        connect(this, &QThread::finished, this, &QThread::deleteLater);
+    }
+
+private:
+    void run() override {
+        m_future.get();
+    }
+
+    std::future<void> m_future;
+};
+
+inline QThread *createThreadImpl(std::future<void> &&future) {
+    return new QThreadCreateThread(std::move(future));
+}
+
+template<typename Function, typename... Args>
+QThread *createQThread(Function &&f, Args &&... args) {
+    using DecayedFunction = typename std::decay<Function>::type;
+    auto threadFunction =
+            [f = static_cast<DecayedFunction>(std::forward<Function>(f))](auto &&... largs) mutable -> void {
+                (void) std::invoke(std::move(f), std::forward<decltype(largs)>(largs)...);
+            };
+
+    return createThreadImpl(std::async(std::launch::deferred,
+                                       std::move(threadFunction),
+                                       std::forward<Args>(args)...));
+}

3rdparty/qscopeguard.h

@@ -0,0 +1,96 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Sérgio Martins <sergio.martins@kdab.com>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QSCOPEGUARD_H
+#define QSCOPEGUARD_H
+
+#include <QtCore/qglobal.h>
+
+
+QT_BEGIN_NAMESPACE
+
+
+template <typename F> class QScopeGuard;
+template <typename F> QScopeGuard<F> qScopeGuard(F f);
+
+template <typename F>
+class QScopeGuard
+{
+public:
+    QScopeGuard(QScopeGuard &&other) Q_DECL_NOEXCEPT
+        : m_func(std::move(other.m_func))
+        , m_invoke(other.m_invoke)
+    {
+        other.dismiss();
+    }
+
+    ~QScopeGuard()
+    {
+        if (m_invoke)
+            m_func();
+    }
+
+    void dismiss() Q_DECL_NOEXCEPT
+    {
+        m_invoke = false;
+    }
+
+private:
+    explicit QScopeGuard(F f) Q_DECL_NOEXCEPT
+        : m_func(std::move(f))
+    {
+    }
+
+    Q_DISABLE_COPY(QScopeGuard)
+
+    F m_func;
+    bool m_invoke = true;
+    friend QScopeGuard qScopeGuard<F>(F);
+};
+
+
+template <typename F>
+QScopeGuard<F> qScopeGuard(F f)
+{
+    return QScopeGuard<F>(std::move(f));
+}
+
+QT_END_NAMESPACE
+
+#endif // QSCOPEGUARD_H

include/global/Utils.hpp

@@ -22,7 +22,7 @@ inline QWidget *mainwindow;
 inline std::function<void(QString)> MW_show_log;
 inline std::function<void(QString, QString)> MW_dialog_message;
 
-// Threading
+// Dispatchers
 
 class QThread;
 inline QThread *DS_cores;

src/global/Utils.cpp

@@ -1,6 +1,7 @@
 #include "include/global/Utils.hpp"
 
 #include "3rdparty/base64.h"
+#include "3rdparty/QThreadCreateThread.hpp"
 
 #include <random>
 
@@ -16,7 +17,6 @@
 #include <QRegularExpression>
 #include <QDateTime>
 #include <QLocale>
-#include <QThreadPool>
 
 #ifdef Q_OS_WIN
 #include "include/sys/windows/guihelper.h"
@@ -250,15 +250,37 @@ void ActivateWindow(QWidget *w) {
 }
 
 void runOnUiThread(const std::function<void()> &callback) {
-    QMetaObject::invokeMethod(mainwindow, callback);
+    // any thread
+    auto *timer = new QTimer();
+    auto thread = mainwindow->thread();
+    timer->moveToThread(thread);
+    timer->setSingleShot(true);
+    QObject::connect(timer, &QTimer::timeout, [=]() {
+        // main thread
+        callback();
+        timer->deleteLater();
+    });
+    QMetaObject::invokeMethod(timer, "start", Qt::QueuedConnection, Q_ARG(int, 0));
 }
 
 void runOnNewThread(const std::function<void()> &callback) {
-    QThreadPool::globalInstance()->start(callback);
+    createQThread(callback)->start();
 }
 
 void runOnThread(const std::function<void()> &callback, QObject *parent) {
-    QMetaObject::invokeMethod(parent, callback);
+    auto *timer = new QTimer();
+    auto thread = dynamic_cast<QThread *>(parent);
+    if (thread == nullptr) {
+        timer->moveToThread(parent->thread());
+    } else {
+        timer->moveToThread(thread);
+    }
+    timer->setSingleShot(true);
+    QObject::connect(timer, &QTimer::timeout, [=]() {
+        callback();
+        timer->deleteLater();
+    });
+    QMetaObject::invokeMethod(timer, "start", Qt::QueuedConnection, Q_ARG(int, 0));
 }
 
 void setTimeout(const std::function<void()> &callback, QObject *obj, int timeout) {