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QtUtils/RunOnObject: Make safe under object destruction

Co-Authored-By: cancel <cancel@cancel.fm>
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riking and cancel committed May 21, 2018
1 parent f31f1a0 commit 268b424843c859d5d063dfa2da8b3edd7670cddc
@@ -34,7 +34,7 @@
static bool QtMsgAlertHandler(const char* caption, const char* text, bool yes_no, MsgType style)
{
return RunOnObject(QApplication::instance(), [&] {
std::optional<bool> r = RunOnObject(QApplication::instance(), [&] {
QMessageBox message_box(QApplication::activeWindow());
message_box.setWindowTitle(QString::fromUtf8(caption));
message_box.setText(QString::fromUtf8(text));
@@ -68,6 +68,9 @@ static bool QtMsgAlertHandler(const char* caption, const char* text, bool yes_no
return false;
});
if (r.has_value())
return *r;
return false;
}
// N.B. On Windows, this should be called from WinMain. Link against qtmain and specify
@@ -1196,13 +1196,16 @@ void MainWindow::OnImportNANDBackup()
});
},
[this] {
return RunOnObject(this, [this] {
std::optional<std::string> keys_file = RunOnObject(this, [this] {
return QFileDialog::getOpenFileName(this, tr("Select the keys file (OTP/SEEPROM dump)"),
QDir::currentPath(),
tr("BootMii keys file (*.bin);;"
"All Files (*)"))
.toStdString();
});
if (keys_file)
return *keys_file;
return std::string("");
});
QueueOnObject(dialog, &QProgressDialog::close);
});
@@ -580,19 +580,25 @@ void NetPlayDialog::OnTraversalError(TraversalClient::FailureReason error)
bool NetPlayDialog::IsRecording()
{
return RunOnObject(m_record_input_box, &QCheckBox::isChecked);
std::optional<bool> is_recording = RunOnObject(m_record_input_box, &QCheckBox::isChecked);
if (is_recording)
return *is_recording;
return false;
}
std::string NetPlayDialog::FindGame(const std::string& game)
{
return RunOnObject(this, [this, game] {
std::optional<std::string> path = RunOnObject(this, [this, game] {
for (int i = 0; i < m_game_list_model->rowCount(QModelIndex()); i++)
{
if (m_game_list_model->GetUniqueIdentifier(i).toStdString() == game)
return m_game_list_model->GetPath(i).toStdString();
}
return std::string("");
});
if (path)
return *path;
return std::string("");
}
void NetPlayDialog::ShowMD5Dialog(const std::string& file_identifier)
@@ -4,7 +4,11 @@
#pragma once
#include <QCoreApplication>
#include <QEvent>
#include <QPointer>
#include <QThread>
#include <optional>
#include <type_traits>
#include <utility>
@@ -15,21 +19,53 @@ class QObject;
// QWidget and subclasses are not thread-safe! This helper takes arbitrary code from any thread,
// safely runs it on the appropriate GUI thread, waits for it to finish, and returns the result.
//
// If the target object is destructed before the code gets to run, the QPointer will be nulled and
// the function will return nullopt.
template <typename F>
auto RunOnObject(QObject* object, F&& functor)
{
using OptionalResultT = std::optional<std::result_of_t<F()>>;
// If we queue up a functor on the current thread, it won't run until we return to the event loop,
// which means waiting for it to finish will never complete. Instead, run it immediately.
if (object->thread() == QThread::currentThread())
return functor();
Common::Event event;
std::result_of_t<F()> result;
QueueOnObject(object, [&event, &result, functor = std::forward<F>(functor) ] {
result = functor();
event.Set();
});
return OptionalResultT(functor());
class FnInvokeEvent : public QEvent
{
public:
FnInvokeEvent(F&& functor, QObject* obj, Common::Event& event, OptionalResultT& result)
: QEvent(QEvent::None), m_func(std::move(functor)), m_obj(obj), m_event(event),
m_result(result)
{
}
~FnInvokeEvent()
{
if (m_obj)
{
(*m_result) = m_func();
}
else
{
// is already nullopt
}
m_event.Set();
}
private:
F m_func;
QPointer<QObject> m_obj;
Common::Event& m_event;
OptionalResultT& m_result;
};
Common::Event event{};
OptionalResultT result = std::nullopt;
QCoreApplication::postEvent(object,
new FnInvokeEvent(std::forward<F>(functor), object, event, result));
event.Wait();
return result;
}
@@ -30,7 +30,7 @@ void Updater::OnUpdateAvailable(const NewVersionInformation& info)
{
bool later = false;
int choice = RunOnObject(m_parent, [&] {
std::optional<int> choice = RunOnObject(m_parent, [&] {
QDialog* dialog = new QDialog(m_parent);
dialog->setWindowTitle(tr("Update available"));
dialog->setWindowFlags(dialog->windowFlags() & ~Qt::WindowContextHelpButtonHint);
@@ -79,7 +79,7 @@ void Updater::OnUpdateAvailable(const NewVersionInformation& info)
return dialog->exec();
});
if (choice == QDialog::Accepted)
if (choice && *choice == QDialog::Accepted)
{
TriggerUpdate(info, later ? AutoUpdateChecker::RestartMode::NO_RESTART_AFTER_UPDATE :
AutoUpdateChecker::RestartMode::RESTART_AFTER_UPDATE);

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