[Tutor] Re: setting up a timer

[Lloyd Kvam]

Thanks for the analysis.  I have given up on a watchdog timer.

The timer need was coming from also starting the remote
MySQL server when necessary.  I have lowered the requirements, so
that it will only start a local server.


Derrick 'dman' Hudson wrote:

> On Tue, Jul 02, 2002 at 07:47:02PM -0400, Lloyd Kvam wrote:
> 
> First, it's too bad you can't use the standard, tried-and-true
> signal.alarm().  It would do exactly what you need.
> 
> | Is there a way to kill a thread?
> 
> Not if it is blocked.  The only way to "kill" a thread is to terminate
> it's run() function from the inside.
> 
> | Or is there some documentation about using exceptions with threads?
> 
> If the exception occurs within the running thread, then the run()
> method should be able to catch it and terminate gracefully.  (if it
> doesn't catch it then I think the thread will just die less
> gracefully)
> 
> Each thread's run() method is like a separate main() (in a C program).
> 
> 
> Hmm, maybe something like this could work :
> 
> 
> import threading
> 
> def foo() :
>     raise Exception
> 
> try :
>     timer = threading.Timer( 10 , foo )
>     timer.start()
>     mysql.connect()  # whatever
>     timer.cancel() # we don't really want the exception anymore
> except Exception :
>     print "timeout!"
> 
> 
> I just sorta tested it, and it seems that the Timer runs in a separate
> thread, so it has no effect on this thread.
> 
> If the mysql connection is blocking and has no built-in timeout, I'm
> not sure if you can actually do anything about it.  It's much easier
> to turn an async call into a sync one than the other way around
> (unless you have signal.alarm()!).
>  
> HTH,
> -D
> 
> 


-- 
Lloyd Kvam
Venix Corp.
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