[Tutor] The thread module

[Bernard Lebel]

Thanks a bunch Kent, this is exactly what I was after.

Bernard


----- Original Message ----- 
From: "Kent Johnson" <kent_johnson at skillsoft.com>
To: <tutor at python.org>
Sent: Saturday, September 04, 2004 7:29 PM
Subject: Re: [Tutor] The thread module


> Bernard,
>
> Thinking about threads can twist your brain in knots, but for simple uses
> its pretty easy. The threading module is simpler to use than thread. To
> start a new thread, create a Thread object passing a function to the
> constructor. Then call start() on the object. The thread will run until
the
> function you pass it returns, or forever if the function doesn't return.
>
> Here is a simple example of creating two threads that run forever, this is
> similar to what you are trying to do:
>  >>> from threading import Thread
>  >>> import time
>
> Here are the two callback functions:
>  >>> def f1():
> ...   while 1:
> ...     print 'f1'
> ...     time.sleep(1)
> ...
>  >>> def f2():
> ...   while 1:
> ...     print 'f2'
> ...     time.sleep(3)
> ...
>
> Create the two threads and start them. You don't have to do this in one
> line from your program but from the console it is easier...
>  >>> Thread(target=f1).start(); Thread(target=f2).start()
> f1
> f2
>  >>> f1
> f1
> f2
> f1
> f1
> f1
> f2
> f1
> f1
> etc.
>
> Another way you could write your program is to have one loop that checks
to
> see if it is time to run any of the tasks. It could keep a list of
> scheduled tasks and check the list each time it wakes.
>
> Kent
>
> At 05:36 PM 9/4/2004 +0200, Bernard Lebel wrote:
> >Hello,
> >
> >It is my first ever attempt at managing threads. And I must admit that I
am
> >absolutely lost! I don't know if I'm using the right approach at all for
> >what I'm after, so if you have any suggestion, do not hesitate!
> >
> >What I'm looking for:
> >I launch a command line shell, import a script, and the script runs
forever.
> >The watches two main things:
> >1- The accessibility of two shared locations on the network, so if one of
> >them goes down (or both), an email is sent to various people. When one
> >server goes down, it is no longer checked. When both server go down, none
> >are checked. A check is performed every 5 minutes.
> >2- The remaining space on several network volumes, and if one goes under
> >5Gb, again, an email is sent. The check is performed no matter what,
every
> >hour.
> >
> >Currently I have two scripts that do the job very well.
> >
> >Now the problem is that I want to consolidate them into one, so I don't
have
> >two python shell running, but one.
> >I figured that using child threads would be a good way to manage this,
> >because each thread could manage task. Basically I am looking at doing
two
> >parallel loops.
> >
> >
> >So I've messed a little bit with the thread module, and have read the pdf
> >tutorial from Norman Matloff, but I'm still confused about the whole
thing.
> >Anyone can recommend tutorial or ressources for this? Or even a different
> >approach for the problem?
> >
> >
> >Thanks in advance
> >Bernard