Question about thread

On Sat, 2004-11-20 at 04:56, Jarek Zgoda wrote:

Are you sure? I keep observing that child threads continue its execution
until completion even if I do nothing in main thread. Consider this example:

Well, I'm very far from an expert, but I've also experienced the
poster's reported behaviour even with quite simple programs. I'm
surprised to hear that the initially described behaviour isn't always
the case, and would be interested in knowing more about when it is, and
is not, generally encountered.

--
Craig Ringer

Diez B. Roggisch wrote:

Even after printing "finished creating threads" all spawned threads
continue its execution up to final "thread nnnn is being destroyed", so
I think there's no need to take any special action (unless it's Python
on iSeries, buy this is another story) to wait for completion.
The OP used the module "thread", while you used "threading" and didn't set
setDaemon(False ). Then python waits until all threads are finished.

Well... I was bit too fast in replying. ;)
From the thread module docs:

When the main thread exits, it is system defined whether the other threads
survive. On SGI IRIX using the native thread implementation, they survive.
On most other systems, they are killed without executing try ... finally
clauses or executing object destructors.

So it looks that using threading should be preferred over using thread,
as presented example works identically on Windows and on linux (it
doesn't work on AS/400, though...).

--
Jarek Zgoda
http://jpa.berlios.de/ | http://www.zgodowie.org/

Jarek Zgoda wrote:

You need to cause the main thread to wait on the child threads until
they've all finished, otherwise - as Peter Hickman just mentioned - your
script will terminate and all threads will end. Ten seconds on Google
found this:

http://www.faqts.com/knowledge_base/view.phtml/aid/1364

Are you sure? I keep observing that child threads continue its execution
until completion even if I do nothing in main thread. Consider this
example:

You are using the real thing - the highlevel threading.Threa d class - not
the underlying thread.start_ne w_thread() function.
The threading module creates a _MainThread (a Thread subclass) instance that
registers itself as an atexit handler and waits for the other (non-demon)
Thread instances to terminate.

Failure-to-provide-the-source-code-will-ultimately-work-against
-companies-sitting-on-a-pile-of-crap-patents-ly yours

Peter

I just looked up for the keywords "python thread example" in google and few
useful links are retrieved. It seems that most of the examples are too complicated.

Scott David Daniels wrote:

Valkyrie wrote:

Thank you for your advice. I have quite seriously searched for it in fact, but
just without the luck on finding such article...

Can you suggest where this information might have shown up
that you would have found it? If so, you may want to submit
a documentation bug or patch request. That is, repay the
group by making it more likely that the next person with your
problem finds their answer on their own.

--Scott David Daniels
Sc***********@A cm.Org

So may I ask is threading do exactly the same in terms of functionalities as
those in thread?
Jarek Zgoda wrote:

Diez B. Roggisch wrote:

Even after printing "finished creating threads" all spawned threads
continue its execution up to final "thread nnnn is being destroyed", so
I think there's no need to take any special action (unless it's Python
on iSeries, buy this is another story) to wait for completion.

The OP used the module "thread", while you used "threading" and didn't
set
setDaemon(False ). Then python waits until all threads are finished.

Well... I was bit too fast in replying. ;)

From the thread module docs:

When the main thread exits, it is system defined whether the other
threads
survive. On SGI IRIX using the native thread implementation, they
survive.
On most other systems, they are killed without executing try ... finally
clauses or executing object destructors.

So it looks that using threading should be preferred over using thread,
as presented example works identically on Windows and on linux (it
doesn't work on AS/400, though...).

Valkyrie wrote:

So may I ask is threading do exactly the same in terms of functionalities
as those in thread?

Yes, even more than thread. threading is considered the somewhat "better"
interface, as it exposes its funtionality in an objectorientied fashion -
and in this case, that's actually better :)
--
Regards,

Diez B. Roggisch