Wt

Hi, I try it. But "Program received signal SIGSEGV, Segmentation fault."...

Is there examples with QtNetwork thats work without segmentation fault? I try build Wt in debug mode and run app under GDB.

I found the problem. Segmentation fault occures if I try setText ( WText ) from slot replyFinished ( QNetworkAccessManager ). So I have one question... Are there rules how Qt object should interact with Wt.

Thanks.

Hi,

This sounds like you're modifying an object from a thread that is not attached (Wt requires some TLS variables to be set to session-related pointers) to a WApplication. This attachment happens automatically, so it's a signal that you're probably doing something wrong.

Before a thread makes changes to a widget tree, it must lock the widget tree (see WApplication::UpdateLock). We've noticed that this is often challenging to get right (deadlocks etc), so we introduced an easier method: you can use WServer::post to have functions executed in the context of a particular WApplication. Locking will then be handled automatically by Wt. See e.g. examples/features/broadcast.

Best regards,

Wim.

As Wim said, you can't access Wt objects from a Qt thread. You should save the Wt session id when you initialize your QtObject and use WServer::post to access Wt widgets:

void Dictionary::create()
{
    ...
    qtSender_ = new QtObject(this);
    qtSender_->setSessionId(sessionId());
    ...
}

void QtObject::doGreet(const QString& name)
{
    WServer::post(session_id, boost::bind(Dictionary::doGreet, wt_, name));
}

Alan, thank you for information.