Function tryRunEventLoop

src/Gui/Application.cpp:2561–2612

}

void tryRunEventLoop(GUISingleApplication& mainApp)
{
    std::stringstream out;
    out << App::Application::getUserCachePath() << App::Application::getExecutableName() << "_"
        << App::Application::uniqueInstanceId() << ".lock";

    // open a lock file with the PID
    Base::FileInfo fi(out.str());
    Base::ofstream lock(fi);

#if !defined(FC_OS_WIN32) || (BOOST_VERSION < 107600)
    std::string filename = out.str();
#else
    std::wstring filename = fi.toStdWString();
#endif
    try {
        boost::interprocess::file_lock flock(filename.c_str());
        if (flock.try_lock()) {
            Base::Console().log("Init: Executing event loop…\n");
            QApplication::exec();

            // Qt can't handle exceptions thrown from event handlers, so we need
            // to manually rethrow SystemExitExceptions.
            if (mainApp.caughtException) {
                throw Base::SystemExitException(*mainApp.caughtException.get());
            }

            // close the lock file, in case of a crash we can see the existing lock file
            // on the next restart and try to repair the documents, if needed.
            flock.unlock();
            lock.close();
            fi.deleteFile();
        }
        else {
            Base::Console().error(
                "Failed to create a file lock for the IPC.\n"
                "The application will be terminated.\n"
                "Attempted lock file: %s",
                fi.filePath().c_str()
            );
        }
    }
    catch (const boost::interprocess::interprocess_exception& e) {
        QString msg = QString::fromLocal8Bit(e.what());
        Base::Console().error(
            "Failed to create a file lock for the IPC: %s\n"
            "Attempted lock file: %s\n",
            msg.toUtf8().constData(),
            fi.filePath().c_str()
        );
    }
}

void runEventLoop(GUISingleApplication& mainApp)
{