QNetworkReply app crash in QThread

I create an QThread using moveToThread(), where I use a QTimer to pull stuff from network instantly.

In construct I call

Code:

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_http = new HttpAdapter(this);

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and in periodically function run

Code:

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_http->Download();

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In httpAdapter header

Code:

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QNetworkReply* _reply;

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Code:

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void HttpAdapter::Download() {
 
    QString url;
    url += Server::get()->GetBaseUrl();
    url += "get.xml";
 
    QNetworkAccessManager * http = new QNetworkAccessManager;
 
    QNetworkRequest request;
    request.setHeader(QNetworkRequest::ContentLengthHeader, "0");
    request.setUrl(QUrl::fromUserInput(url));
 
    _reply = http->get(request);
 
    connect(_reply,SIGNAL(finished()),this, SLOT(Finished()));
    connect(_reply,SIGNAL(readyRead()),this, SLOT(ReadyData()));
    connect(_reply,SIGNAL(error(QNetworkReply::NetworkError)),this, SLOT(foldersError(QNetworkReply::NetworkError)));
    connect(_reply,SIGNAL(sslErrors ( const QList<QSslError> & )),this, SLOT(SslErrors( const QList<QSslError> &)));
}

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The on finish...

Code:

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void HttpAdapter::Finished() {
    DEBUGME_MSG("finished");
 
    int httpCode = _reply->attribute( QNetworkRequest::HttpStatusCodeAttribute ).toInt();
    if (httpCode != 200) {
        INFO_DEBUGME("HTTP CODE " + QString::number(httpCode));
        return;
    }
 
    if (!_reply->isFinished()) {
        return;
    }
 
    if (!_reply->isReadable()) {
        return;
    }
 
    _data = _reply->readAll();
    _reply->deleteLater();
 
    if (_data.isEmpty()) {
        INFO_DEBUGME("DATA EMPTY");  
        return;
    }
 
    //success
}

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And THE CRASH IS ON

Code:

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_data = _reply->readAll();

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The crash happen randomly, I would say in 5% of the calls, Any idea why ??

Get rid of the memory leak related to creating the access manager object at every iteration and then see if the problem persists.

How do I do it ?

QNetworkAccessManager * http = new QNetworkAccessManager;

on finished

http->deleteLater() ?

I have tried

Code:

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delete _reply->manager();

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always crash

Quote:

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Originally Posted by migel

How do I do it ?

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You rewrite the code so it doesn't leak memory. For example by reusing the same object.

Quote:

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always crash

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Well, if "reply" is invalid then "reply->manager()" will surely be invalid as well.

I have put it that to the construct

Code:

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_http = new QNetworkAccessManager;

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So I am using same object every call, app crashed on readAll() again after few minutes.

Any clues ?

You need to provide us with more complete code. I'm especially interested in when and how you call this Download() method. My guess is that when finished() is emitted, your reply is already invalid or overwritten by something else.