QNetworkAccessManager::get spawns 3 threads and I cannot close them

gsmember

Hello guys,
I am really getting headache with this problem.

I will show you the affected piece of code:
request.h:
@class Request: public QObject{
Q_OBJECT
public:
Request();
~Request();
void func_startRequest();

private:
QNetworkAccessManager *manager;
QNetworkReply *reply;
QUrl url;

public slots:
void slot_requestFinished();
@

request.cpp:
@
#include "request.h"

Request::Request(){
manager=new QNetworkAccessManager(this);
reply=0;
}

Request::~Request(){
if(manager!=0){
manager->deleteLater();
}
if(reply!=0){
reply->deleteLater();
}
}

void Request::func_startRequest(){
QNetworkRequest request;
request.setUrl(QUrl("http://qt-project.org/"));

reply=manager->get(request);

connect(reply, SIGNAL(finished()), this, SLOT(slot_requestFinished()));

}

void Request::slot_requestFinished(){
disconnect(reply,SIGNAL(finished()),this,SLOT(slot_requestFinished()));

/*QNetworkSession session(manager->configuration());
session.close();
session.stop();
reply->abort();
reply->close(); I have tried all of this methods, nothing shut down the threads */

}
@

My problem is that, whenever I call manager->get(), this spawns 3 threads, which I am unable to shut down. After a while (running many requests) there were a huge amount of running threads. They are consuming RAM and running out of max open file descriptors...

Maybe someone could help me with this problem. I would really appreciate that!

Thanks guys

_gs

gsmember

I am talking about threads, not processess. After the first request there were four running thread, the main thread plus 3 threads started by QNAM.

SGaist

Hi and welcome to devnet,

This sounds like a rather strange behavior. What version of Qt are you using on which platform ?

gsmember

Hello,
thanks for your reply.

Sorry I forgot to mention the specs:

Qt 4.8.4 on Debian 5

SGaist

Just to be sure, aren't you forgetting to delete the reply ?

gsmember

Yes, I have also tried to delete the manager and the reply (with deleteLater() ) right after the finished() signal was thrown. Deleting the manger caused the running process amount (opened by QNAM) to reduce to 2 (instead of 3).

And I am very confident that the problem relies on the QNAM, because the three processess (shown in htop and ptree) are spawned right after I call manager->get().

SGaist

Did you already check if something was reported on the "bug report system":http://bugreports.qt-project.org/issues ?

gsmember

Yes, I have found the following closed bugreport, which seems to be very similar to my problem. Indeed, I am hitting the open file limit, but I as penny said, QNAM does not provide any method (or any known one) to close the processess.

https://bugreports.qt-project.org/browse/QTBUG-20148

SGaist

You're not really in the same use case. You could try asking on the interest mailing list to see whether this is an intended behavior. You'll find Qt's developers/maintainers there (this forum is more user oriented)

gsmember

Okay I will do so. Thank you for your interests.

_gs