Application does no longer start in Qt Creator once it has run into segfault in Linux

[matoom]

I figured out why this was happening and it wasn't related to qt creator but i can't find a way to delete this post.

Just for the odd chance someone runs into this issue. It was cause by using QSharedMemory to allow only single instance of application process to run. In Linux/Unix the shared memory did not get released after application crashed.

int main(int argc, char *argv[]) {
    QSharedMemory shared(QDir::currentPath());
    if(!shared.create(512, QSharedMemory::ReadWrite)) {
        Log4Qt::Logger::logger(QLatin1String("ErrorLogger"))->info("Application already running.");
        exit(0);
    }
...
}

int main(int argc, char *argv[]) {
    QSharedMemory shared(QDir::currentPath());
    if(!shared.create(512, QSharedMemory::ReadWrite)) {
        Log4Qt::Logger::logger(QLatin1String("ErrorLogger"))->info("Application already running.");
        exit(0);
    }
...
}

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[anda_skoa]

Yes, on Unix shared memory is "owned" by the operating system itself: http://qt-project.org/doc/qt-4.8/qsh...y.html#details

An approach that should work better cross-platform is using a QLocalServer.
Has the additional benefit that you can use QLocalSocket in the second instance to communicate with the first one, e.g. passing command line arguments of the new invocation.

Cheers,
_