apscheduler error

[Alice Bevan–McGregor]

Howdy!

On 2011-01-07 17:08:28 -0800, linna li said:
> I tried to use the apscheduler and used the sample code below from the 
> tutorial, but got the error message: Exception in thread APScheduler 
> (most likely raised during interpreter shutdown). What's going on here? 
> I really appreciate any help!

After talking a bit with Alex Grönholm it seems this is an issue raised 
fairly often (not always in the context of this package) and is not 
really a problem with APScheduler.  It has far more to do with 
attempting to start a thread, then immediately exiting the main thread. 
 That's not how threading is supposed to be used, so don't do it.  ;)

APScheduler 2.0 adds some improved examples, according to Alex, that 
don't suffer the "problem" demonstrated by the short code snippit you 
provided.

A package of mine, TurboMail, suffers from the same threading issue if 
used improperly; you enqueue e-mail, it starts a thread, then you 
immediately exit.  TM tries to work around the issue, but in most cases 
that workaround does not work properly.  (You get strange uncatchable 
exceptions printed on stderr though AFIK the e-mail does get sent 
correctly, your application may hang waiting for the thread pool to 
drain if you have a "minimum thread count" option set.)

I hope this clears things up a bit,

	- Alice.