Threading & garbage collection

[Gordon McMillan]

Matt Gushee wrote:

> I'm trying to write a subclass of threading.Thread where each
> thread:
> 
>   1) is invoked by a GUI event handler
>   2) collects some data (to be exact, it downloads a web page
> 	and extracts some information from it), and finally
>   3) invokes a GUI method to display the data

It would probably be wise (and with some GUIs, absolutely 
vital) to make sure that all the GUI calls are made on the GUI 
thread. In other words, the worker thread should probably post 
the data to the GUI thread somehow. Queue.py is a likely 
candidate for passing the data. Depending on the GUI, you 
may be able to notify the GUI thread when the data is 
available, or the GUI thread may have to periodically check for 
it.


> ...Do the standard
> rules about circular references apply to threads? I.e., should I
> add something like:
> 
> 	self.win = None
> 
> to the above?

Sure thing.

- Gordon (who lives 2.5 hrs downeast from you)