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i wanna write a qt c++ lib using the pimpl idiom.

Based on this post How to use the Qt's PIMPL idiom? i have written a little program.

Compiling and running is ok but if i wanna close the client with deleteLater() the Prog raise an error:

Client: destroy instance!
ClientPrivate: destroy instance!
double free or corruption (out)

Child terminated with signal = 0x6 (SIGABRT)

I (must) using qt5.6. gcc9, debian buster (and windows later). i'm new in the world of qt's c++ framwork and I unfortunately do not know 100% the internal mechanisms of Qt... where is my problem?

thx!

// public header

namespace X
{
    namespace Y
    {
        class GCDE_DLL_EXPORT Client; // Marco generated by CMake
        class ClientPrivate;
        class Client: public QObject
        {
            Q_OBJECT
            Q_DECLARE_PRIVATE(Client)
            QScopedPointer<ClientPrivate> d_ptr;

        public:
            Client(QObject* parent = Q_NULLPTR);
            ~Client();
        };
    }
}

// private header
namespace X
{
    namespace Y
    {
        class ClientPrivate
        {
            // disable copy ctr's
            Q_DISABLE_COPY(ClientPrivate)

            // Ptr to interface
            Q_DECLARE_PUBLIC(Client)
            Client* q_ptr;

        public:
            ClientPrivate(Client* interf);
            ~ClientPrivate();
        };
    }
}

// impl cpp
namespace X
{
    namespace Y
    {
        ClientPrivate::ClientPrivate(Client* interf):
                q_ptr(interf)
        {}


        ClientPrivate::~ClientPrivate()
        {
            qDebug() << "ClientPrivate: destroy instance!";
        }


        Client::Client(QObject* parent): QObject(parent)
                d_ptr(new ClientPrivate(this))
        {}

        Client::~Client()
        {
            qDebug() << "Client: destroy instance!";
        }
    }
}

// tester
#include <QtCore/QObject>
#include <QtCore/QTimer>
#include <QtCore/QCoreApplication>

#include <socket.hpp>

int main(int argc, char *argv[])
{
    using namespace X;
    QCoreApplication qapp(argc, argv);

    Y::Client clt;

    QTimer::singleShot(2000, &clt, SLOT(deleteLater())); // after 2s -> raise double free

    return qapp.exec();
}
yves84
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  • 1
    You must not delete an object on the stack - c++ basics, nothing Qt specific. – chehrlic Apr 02 '21 at 09:31
  • Ahh, I am stupid xD ! Thx! The Tester is the Problem. clt is not dynamic alloc... i have only focus the classes... – yves84 Apr 02 '21 at 09:45

1 Answers1

0

Ahh, I am stupid xD ! Thx! The Tester is the problem. clt is not dynamic alloc... i have only focus the classes...

yves84
  • 1