im doing something wrong with QNetworkAccessManager thread request free threads

[umen]

i know that in version 4.8 each http request gets its own thread to run ,
im doing links checker app that doing allot of http request in while loop
i notice in the windows task manager that my app is using more then 1600 threads over time and the number never gos down only up until its crash the app . ( i guessing it is the couse ) my question is does QNetworkAccessManager has option to use thread pool ?
or it has option to clean its thread after it finish its http request?

this is the main loop :

while(!rpm_urlStack->isEmpty())
    {
         QString url = rpm_urlStack->top();
         rpm_urlStack->pop();
 
         QString urlForReq(url);
 
         bool returnVal = true;
         QNetworkRequest request;
 
         request.setUrl(QUrl(urlForReq));
         request.setRawHeader("User-Agent", USER_AGENT.toUtf8());
         request.setRawHeader("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.7");
         request.setRawHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
         request.setRawHeader("Accept-Language", "en-us,en;q=0.5");
         request.setRawHeader("Connection", "Keep-Alive");
 
          QEventLoop loop;
          reply = m_networkManager->get(request);
          connect(reply, SIGNAL(finished()), &loop, SLOT(quit()));
          loop.exit();
          if(!loop.isRunning())
          {
 
             loop.exec();
 
          }
 
          RequestFinishedHandler(reply);
 
    }
 
RequestFinishedHandler(QNetworkReply *reply)
{
 
 
 if (reply->error() > 0) {
        QNetworkReply::NetworkError networkError = reply->error();       
        QString err = reply->errorString(); 
 
 
    }
    else {
        QVariant vStatusCodeV =  reply->attribute(QNetworkRequest::HttpStatusCodeAttribute); 
        QMutexLocker lock(_pMutex); // _pMutex defined as class member
        char *buffer;
        buffer  = getCurrentDateTime();
        QTextStream out(m_file);
        out << buffer <<"  "<<   _sCurrentUrl << "\n";  
        lock.unlock();
        if(vStatusCodeV.toInt() == 200)
        {
               QString ApiResponse;
               QByteArray data;              
               data=reply->readAll();
               ApiResponse.append(QString::fromUtf8(data));
 
         } 
 
    }
    reply->deleteLater();
 
}

while(!rpm_urlStack->isEmpty())
    {
         QString url = rpm_urlStack->top();
         rpm_urlStack->pop();

         QString urlForReq(url);

         bool returnVal = true;
         QNetworkRequest request;

         request.setUrl(QUrl(urlForReq));
         request.setRawHeader("User-Agent", USER_AGENT.toUtf8());
         request.setRawHeader("Accept-Charset", "ISO-8859-1,utf-8;q=0.7,*;q=0.7");
         request.setRawHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
         request.setRawHeader("Accept-Language", "en-us,en;q=0.5");
         request.setRawHeader("Connection", "Keep-Alive");

          QEventLoop loop;
          reply = m_networkManager->get(request);
          connect(reply, SIGNAL(finished()), &loop, SLOT(quit()));
          loop.exit();
          if(!loop.isRunning())
          {

             loop.exec();

          }

          RequestFinishedHandler(reply);

    }

RequestFinishedHandler(QNetworkReply *reply)
{


 if (reply->error() > 0) {
        QNetworkReply::NetworkError networkError = reply->error();       
        QString err = reply->errorString(); 


    }
    else {
        QVariant vStatusCodeV =  reply->attribute(QNetworkRequest::HttpStatusCodeAttribute); 
        QMutexLocker lock(_pMutex); // _pMutex defined as class member
        char *buffer;
        buffer  = getCurrentDateTime();
        QTextStream out(m_file);
        out << buffer <<"  "<<   _sCurrentUrl << "\n";  
        lock.unlock();
        if(vStatusCodeV.toInt() == 200)
        {
               QString ApiResponse;
               QByteArray data;              
               data=reply->readAll();
               ApiResponse.append(QString::fromUtf8(data));

         } 

    }
    reply->deleteLater();

}

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[ChrisW67]

Your code never returns to the event loop so the QNetworkReply objects will not be deleted until the entire queue is finished

I really do not know why you are trying to build a blocking system rather than simply connect the QNetworkAccessManager::finished() signal to a slot to handle the finished reply. The "problem" would then be a non-issue. I also see no reason for the mutex in the RequestFinishedHandler: yes, QNetworkAccessManager uses threads internally, but your code remains single-threaded.

[umen]

hello and thanks for the replay ,
im using eventloop and blocking system , because the flow of the app depend on the return of the http requests , i can just make a sync requests
and see what happen .
more info is that each such while loop is happening inside worker thread and i have 10 like this in each given moment , this is why i have the mutex.
they all writing to the same single file.

about the single threaded i do see 1600++ threads created from my app in the window manager , i guess is from the http requests .
but the problem is they never cleaned.
again as the topic says maybe im doing it all wrong .

[ChrisW67]

They are not cleaned up because the QNetworkReply objects are never being deleted.

[umen]

where do you suggest to clean them ? is it by simple

delete reply