[Qt-interest] Is it sensible to call "delete this; " at the end of a QThread's run method?

[Chris Vickery]

The thread affinity thing doesn't really make sense, if you remove that part
then you can simply do this:

connect(this, SIGNAL(finished()), this, SLOT(deleteLater()));

The signal name might be wrong, check the docs...

You're really better off using the thread object to fire off a worker class
so that the thread affinity makes sense.

You're going to get annoying thread object deleted while thread is still
running errors, even if the event loop has exited. Basically it's impossible
to properly clean up a QThread object that you've run moveToThread(this)
on...

Chris
On May 29, 2011 7:21 PM, "K. Frank" <kfrank29.c at gmail.com> wrote:
> Hello List!
>
> I have a worker class derived from QThread, and now I want to be able
> to clean up its instance programmatically while the application is
running,
> rather than just when the application terminates.
>
> I'm thinking of using QThread's quit slot to cause it to exit its event
> loop, and then having the the run method execute delete(this).
>
> Specifically:
>
> void run() {
> timer_ = new QTimer(this);
> connect(timer_, SIGNAL(timeout()), this, SLOT(update()));
> timer_->start (updateTime_);
> exec();
> delete (this); // <-- new line of code; does it make sense?
> }
>
>
> (Note, just for your information, and with no intention to reopen the
> debate: My QThread object has thread affinity for itself as I call
> "moveToThread (this);" in the QThread's constructor.)
>
> The point is that I don't want to delete the QThread from the gui thread
> (where it was new'ed) because I don't want to rip it our from under itself
> while it might still processing its event loop.
>
> So the idea is my gui thread triggers QThread's quit slot to cause the
> QThread's exec() method to return. (Am I correct that the quit slot causes
> the QThread's event loop to exit cleanly and synchronously after any of
> my custom event-processing code has completed and returned control
> to the event loop?) After exec() returns, "delete (this)" releases the
> QThread object's memory (and hypothetically any other resources it
> allocated). Is this scheme legitimate? Or would I be setting myself
> up for trouble somehow?
>
> (As an aside, is it okay to call QThread's quit() (or exec()) member
> function directly from the gui thread, rather than through a signal-slot
> connection? Also, am I right that because the QThread allocates the
> QTimer it uses with "timer_ = new QTimer (this);", i.e., setting itself as
> the QTimer's parent, the QThread's destructor will delete the QTimer?)
>
> Thanks for any information on this.
>
>
> K. Frank
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