Simplest app with QNetworkAccessManager and First-chance exception

[wysota]

Since the very beginning I was suspecting some problem with threads which could explain what is going on. However you said the code you posted was a complete testbed so the only threads running are those related to QNetworkAccessManager. Or at least that should be the case. On the other hand we can see around 10 threads in your app. Where are they coming from? Are you sure there is no additional code involved? Are you linking with some external libraries or something like that? Where does qmyapp.h come from?

[allexz]

On the other hand we can see around 10 threads in your app. Where are they coming from?

I wonder myself...

Are you sure there is no additional code involved? Are you linking with some external libraries or something like that? Where does qmyapp.h come from?

Yes, I'm sure. qmyapp.h - it contained custom QApplication derived class, but now I don't use it. I even removed it from the project - nothing changed.
Input libraries: qtmaind.lib;QtCored4.lib;QtGuid4.lib;QtNetworkd4.l ib;

OK, thank you anyway!

[pke]

Did you solve this? I am running into the exact same problem in my code. Same stacktrace, same simple code, just a get() call with the QNAM. And its 100% reproducible.

[crioux]

I get this error as well, without even using the QNAM. It's loading 'qnativewifibearerd' and then crapping out in it after it tries to to call 'closeHandle'.
My stack trace looks nearly the same.

--chris

[ChrisW67]

@pke: Are you using exactly the posted code without the customised QApplication, VS2010, and Qt 5.0.0? If so, upgrade your Qt and do a clean build.

@crioux: So you are crashing in this fashion with a program that contains nothing except a QApplication instantiation and Designer Ui. Forgive me if I do not trust that assertion. Do a complete rebuild. Post a single file example and complete version details if the problem persists.

[abc100m]

I have the same issue, QNetworkAccessManager cause a debug output like :
test.exe .. 0x74fcb727 .....: 0x0000000D: The data is invalid


my test environment is :

window 7 64 bit
visual studio 2008
Qt 5.1

[wysota]

I have the same issue,

How do you know it is the same issue?

[abc100m]

I want to reproduce this issue, but same character is Chinese.

Ok, I change a bit code that provide by #1. I create a new Qt project, and have two button:

void Test::Request_finished(QNetworkReply *reply)
{
//reply->deleteLater();
}

void Test::Button_clicked()
{
manager = new QNetworkAccessManager(this);

QObject::connect(manager, SIGNAL(finished(QNetworkReply *)), this, SLOT(Request_finished(QNetworkReply *)));
QNetworkRequest request(QUrl("http://www.google.com"));
reply = manager->get(request);
}

void Test::destroy_clicked()
{
qDebug() << "to delete reply...";
if (reply)
{
reply->abort();
delete reply;//->deleteLater();
reply = NULL;
}

qDebug() << "to delete manager...";
if (manager)
{
delete manager;
manager = NULL;
}

qDebug() << "reply, manager destroyed...";
}

now, I begin to debug my test program in visual studio IDE(just F5).

after the program is run, I break it to see how many threads, and now just have 6 threads:
--------
0 > 3012 主线程 主线程 _free_base æ*£å¸¸ 0
0 1228 RPC 线程 RPC 回调线程 7739fd81 æ*£å¸¸ 0
0 6636 辅助线程 Win32 线程 773a014d æ*£å¸¸ 0
0 5628 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 5948 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 6696 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
------------------

now I click button1 to execute void Test::Button_clicked(), after executed I see there 14 threads:
---------------------
0 > 3012 主线程 主线程 _free_base æ*£å¸¸ 0
0 1228 RPC 线程 RPC 回调线程 7739f8c1 æ*£å¸¸ 0
0 5928 辅助线程 Win32 线程 7739f8c1 æ*£å¸¸ 0
0 7972 辅助线程 Win32 线程 7739f949 高于æ*£å¸¸ 0
0 5632 辅助线程 Win32 线程 773a014d 时间关键 0
0 6636 辅助线程 Win32 线程 773a014d æ*£å¸¸ 0
0 4404 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 5528 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 5628 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 6260 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 6696 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 6640 辅助线程 Qt HTTP thread QMetaObject::activate æ*£å¸¸ 0
0 8092 辅助线程 Qt bearer thread QMetaObject::activate æ*£å¸¸ 0
0 4496 辅助线程 Thread (pooled) QWaitConditionPrivate::wait æ*£å¸¸ 0
---------------------

and these time I click button2 to execute void Test::destroy_clicked(), after execute I see there 10 threads left:
---------------------
0 > 3012 主线程 主线程 _free_base æ*£å¸¸ 0
0 5928 辅助线程 Win32 线程 7739f8c1 æ*£å¸¸ 0
0 5632 辅助线程 Win32 线程 773a014d 时间关键 0
0 6636 辅助线程 Win32 线程 773a014d æ*£å¸¸ 0
0 3092 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 4060 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 5528 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 5628 辅助线程 Win32 线程 773a1f36 æ*£å¸¸ 0
0 4912 辅助线程 qt_adopted_thread_watcher_function QArrayData::data æ*£å¸¸ 0
0 8092 辅助线程 Qt bearer thread QMetaObject::activate æ*£å¸¸ 0
---------------------------

after about 1 minute, I close the test program, and the visual studio debug window shows:
--------------------------
to delete reply...
to delete manager...
线程 'Qt HTTP thread' (0x19f0) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
reply, manager destroyed...
线程 'Win32 线程' (0xc14) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'Win32 线程' (0x15fc) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
test.exe ä¸*çš„ 0x74fcb727 处最可能的异常: 0x0000000D: The data is invalid
线程 'Win32 线程' (0x1728) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'qt_adopted_thread_watcher_function' (0x1330) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'Qt bearer thread' (0x1f9c) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'Win32 线程' (0x1600) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'Win32 线程' (0x1338) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'Win32 线程' (0x1598) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'Win32 线程' (0xfdc) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'Win32 线程' (0x19ec) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
线程 'Win32 线程' (0xe9c) å·²é€€å‡ºï¼Œè¿”å›žå€¼ä ¸º 0 (0x0)。
程序“[4784] test.exe: æœ¬æœºâ€å·²é€€å‡ºï¼Œè¿ ”回值为 0 (0x0)。
------------------------------------------------

[wysota]

Your code goes way past an empty project with an instance of QNetworkAccessManager that does nothing.

If your back trace is different than OP's then please start your own thread instead of hijacking this one.

[abc100m]

Different back trace but have the same result,

For test this case, I create a new Visual Studio project, and my test code list below. May be someone can test this code

//test.h
#ifndef TEST_H
#define TEST_H
 
#include <QtWidgets/QMainWindow>
#include <QtNetwork>
#include "ui_test.h"
 
 
class Test : public QMainWindow
{
    Q_OBJECT
 
public:
    Test(QWidget *parent = 0);
    ~Test();
 
    public slots:
        void Button_clicked();
        void destroy_clicked();
        void Request_finished(QNetworkReply *reply);
 
private:
    Ui::TestClass ui;
    QNetworkReply* reply;
    QNetworkAccessManager* manager;
};
 
#endif // TEST_H

//test.h
#ifndef TEST_H
#define TEST_H

#include <QtWidgets/QMainWindow>
#include <QtNetwork>
#include "ui_test.h"


class Test : public QMainWindow
{
    Q_OBJECT

public:
    Test(QWidget *parent = 0);
    ~Test();

    public slots:
        void Button_clicked();
        void destroy_clicked();
        void Request_finished(QNetworkReply *reply);

private:
    Ui::TestClass ui;
    QNetworkReply* reply;
    QNetworkAccessManager* manager;
};

#endif // TEST_H

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//test.cpp
#include "test.h"
#include <QtWidgets>
 
Test::Test(QWidget *parent)
: QMainWindow(parent)
{
    ui.setupUi(this);
    QObject::connect(ui.pushButton, SIGNAL(clicked()), this, SLOT(Button_clicked()));
    QObject::connect(ui.btn_destroy, SIGNAL(clicked()), this, SLOT(destroy_clicked()));
 
    reply = NULL;
    manager = NULL;
}
 
Test::~Test()
{
}
 
void Test::Request_finished(QNetworkReply *reply)
{
    //reply->deleteLater();
}
 
void Test::Button_clicked()
{
    manager = new QNetworkAccessManager(this);
    QObject::connect(manager, SIGNAL(finished(QNetworkReply *)), this, SLOT(Request_finished(QNetworkReply *)));
    QNetworkRequest request(QUrl("http://www.google.com"));
    reply = manager->get(request);
}
 
void Test::destroy_clicked()
{
    qDebug() << "to delete reply...";
    if (reply)
    {
        reply->abort();
        delete reply;//->deleteLater();
        reply = NULL;
    }
 
    qDebug() << "to delete manager...";
    if (manager)
    {
        delete manager;
        manager = NULL;
    }
 
    qDebug() << "reply, manager destroyed...";
}

//test.cpp
#include "test.h"
#include <QtWidgets>

Test::Test(QWidget *parent)
: QMainWindow(parent)
{
    ui.setupUi(this);
    QObject::connect(ui.pushButton, SIGNAL(clicked()), this, SLOT(Button_clicked()));
    QObject::connect(ui.btn_destroy, SIGNAL(clicked()), this, SLOT(destroy_clicked()));

    reply = NULL;
    manager = NULL;
}

Test::~Test()
{
}

void Test::Request_finished(QNetworkReply *reply)
{
    //reply->deleteLater();
}

void Test::Button_clicked()
{
    manager = new QNetworkAccessManager(this);
    QObject::connect(manager, SIGNAL(finished(QNetworkReply *)), this, SLOT(Request_finished(QNetworkReply *)));
    QNetworkRequest request(QUrl("http://www.google.com"));
    reply = manager->get(request);
}

void Test::destroy_clicked()
{
    qDebug() << "to delete reply...";
    if (reply)
    {
        reply->abort();
        delete reply;//->deleteLater();
        reply = NULL;
    }

    qDebug() << "to delete manager...";
    if (manager)
    {
        delete manager;
        manager = NULL;
    }

    qDebug() << "reply, manager destroyed...";
}

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