corrupted double-linked list error after closing main window

[Dijkstra]

so i get a very long error starting with

corrupted double-linked list: 0x0000000002081a70 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x777f5)[0x7fdae30987f5]
/lib/x86_64-linux-gnu/libc.so.6(+0x7e6fd)[0x7fdae309f6fd]
/lib/x86_64-linux-gnu/libc.so.6(+0x80688)[0x7fdae30a1688]

after closing the main window what i am trying to do is choose a json file and parse it extract data from it
the data is extracted correctly but closing the mainwindow causes the app to crash
this is how i kill the qprocesses

void plugin::terminate_kill(){
    QProcess::execute("kill", QStringList()<< "-9" << QString::number(getpid()));
}

this is how i run them and track if they finished then stop them

void Sessions::Run(QString type){

    for(auto it:Plugins){
        //std::cout<<(*it)<<std::endl;
        if(it->gettype()==type)
            it->run();
    }
    emit(start_cpu_gpu(false));
}
void Sessions::recievefinishedid(int id){
    std::cout<<"plugin number "<<id<<" has finished"<<std::endl;
    add_finished();
    Plugins[id]->terminate_kill();
    if(get_finished()==get_existing()){
        stop_servers();
    }
}
void Sessions::stop_servers(){
    for(auto it:Plugins){
        if(it->gettype()=="server"){
            it->terminate_kill();
            std::cout<<it->getname().toStdString()<<' '<<"stopped"<<std::endl;
        }
    }
    emit(plugins_finished(false));
}

and this is how i start it

void plugin::run(){
    //plugin_process.start("/bin/bash",QStringList()<<getfilename()<<" -v3 -j "<<getjsonfilename());
    plugin_process.start("/bin/bash",QStringList() << "-c" <<getfilename());
    if(plugin_process.pid()){
        QString nstart=getname()+" started";
        std::cout<<getname().toStdString()<<" started"<<std::endl;
        setpid(plugin_process.pid());
        QObject::connect(&plugin_process , SIGNAL(finished(int,QProcess::ExitStatus)), this, SLOT(processFinished(int, QProcess::ExitStatus)));
        QObject::connect(&plugin_process , SIGNAL(started()), this, SLOT(processStarted()));
        QObject::connect(&plugin_process , SIGNAL(readyReadStandardOutput()), this, SLOT(processStandardOutput()));
    }
    else{
        std::cout<<"failed to start "<<getname().toStdString()<<std::endl;
    }
}

[JonB]

@Dijkstra
Some things show up when main window closed/program exited, e.g. double-deletion of objects.

I do not see you using a "double-linked list". As ever with a crash, same every time, run in debugger. When it crashes debugger should break, look at stack trace window, trace back to your own code to see where it came from.

BTW, in terminate_kill() you kill the pid from getpid(). Which getpid() is this? If it's Linux's ::getpid() you are killing yourself....

[Dijkstra]

@JonB ran in debugger and this was the output after the error

RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'
RTTI symbol not found for class 'QWidget'

[JonB]

@Dijkstra
No, that is irrelevant. Please take the time to read what I wrote. What did I write in bold?

[Dijkstra]

@JonB no its a getter to get the qprocess pid
do u mean this ?

i ran in debugger and that is what i got

[JonB]

@Dijkstra said in corrupted double-linked list error after closing main window:

no its a getter to get the qprocess pid

That's OK then.

do u mean this ?

Not the top window, because that window is entitled Disassembler. But yes for the window underneath that. But you have stopped at the bottom-most 11 calls --- which btw does indeed show your problem is inside some free(), exactly as I suspected (trying to free something bad/already freed, during some "font destroy"). You need to keep scrolling down that pane, till we can see where in your code it came from. (I'm not sure, but you may be able to "copy as text" (right-click?) and paste here, instead of screenshots.)

[Dijkstra]

@JonB this is the correct scrrenshot

[JonB]

@Dijkstra
So it's failing while destructing some QString, which in turn is happening while destructing MainWindow. Please, like I have said several times, move the "current frame" into your code. There's no point being shown it has died in qdataarray.h, we need to see what line in your code is the cause, and then figure out what you have done wrong about it. Maybe you can even break in the main window destructor so we can see which QString (content) it is trying to destruct. I'll look at it again if/when you show the needed information.....

[Dijkstra]

@JonB i dont know where the current frame is and now the table changes for no reason and shows this

[JonB]

@Dijkstra said in corrupted double-linked list error after closing main window:

and now the table changes for no reason

No comment.

Do you do anything with fonts in your app? All the errors seem to have something to do with that. Can't say more from the information you show.

[Dijkstra]

@JonB after trying to debugg i found that the problem occurs when i parse the json file and this is the function

void Sessions::parsejsonfile(QString inputFileName){

    QJsonParseError jsonError;
    QFile file;
    file.setFileName(inputFileName);
    bool open=file.open(QIODevice::ReadOnly | QIODevice::Text);
    if(open){
        QString file_values=file.readAll();
        file.close();
        QJsonDocument parsejson = QJsonDocument::fromJson(file_values.toUtf8(),&jsonError);
        if (QJsonParseError::NoError != jsonError.error) {
            std::cout<<"error parsing json file"<<std::endl;
        }
        else{
            QJsonObject jsonobject = parsejson.object();
            QJsonValue plugin_file_name=jsonobject.value(QString("file"));
            QJsonValue jsonfile=jsonobject.value(QString("JSON_File"));
            QJsonValue name=jsonobject.value(QString("name"));
            QJsonValue number_instances=jsonobject.value(QString("number_instants"));
            plugin *Plugin=new plugin();
            Plugin->setfilename(plugin_file_name.toString());
            Plugin->setjsonfilename(jsonfile.toString());
            Plugin->setname(name.toString());
            Plugin->setnumber_instances(number_instances.toString().toInt());
            Plugin->settype(QString("plugin"));
            Plugin->setid(0);
            QObject::connect(Plugin, SIGNAL(sendfinishedid(int)),
                             this, SLOT(recievefinishedid(int)));
            QObject::connect(Plugin, SIGNAL(LogMessage(QString)),
                             this, SLOT(logMessage(QString)));
            Plugins.push_back(Plugin);
            add_existing();
            QJsonValue gpu_servers_configurations=jsonobject.value(QString("gpu_servers_configurations"));
            QJsonArray array=gpu_servers_configurations.toArray();
            int idx=1;
            foreach(const QJsonValue &it,array){
                plugin *server=new plugin();
                server->setname(it.toObject().value(QString("name")).toString());
                server->setjsonfilename(it.toObject().value(QString("JSON_File")).toString());
                server->setfilename(it.toObject().value(QString("path")).toString());
                server->setnumber_instances(it.toObject().value(QString("number_instants")).toString().toInt());
                server->settype(QString("server"));
                server->setid(idx);
                Plugins.push_back(server);
                idx++;
            }
        }
    }
    else{
        std::cout<<"failed to open file"<<std::endl;
    }
}

when i fire this function only after choosing the file and closing the error occurs when i remove it no probhlems happen

[JonB]

@Dijkstra
Don't know why that is relevant, or why this has a connection to fonts, if indeed it does. Comment out bits here --- especially whatever else it calls/causes to happen --- and see how you go.