sqlobject-discuss

[SQLObject] threading with spyce?

[<jws...@ra...>]

I'm considering using mod_python + spyce + sqlobject, but mod_python
apparently needs to have python built without threading. Is that a
deal-breaker for SO?

Re: [SQLObject] threading with spyce?

[Ian B. <ia...@co...>]

jws...@ra... wrote:
> I'm considering using mod_python + spyce + sqlobject, but mod_python
> apparently needs to have python built without threading. Is that a
> deal-breaker for SO?

Not really a problem.  SQLObject is threadsafe (or at least tries to me 
;), which is merely irrelevant if you aren't using threads.

There may be problems though because the threading module won't be 
present.  You might need to use a fake threading module of some sort, 
maybe just like:

# threading.py
class Lock:
     def acquire(self): pass
     def release(self): pass

This way SQLObject can pretend to lock sections of code.

You'll have to be careful about caching, since SQLObject can't maintain 
cache consistency on its own in a multi-process environment.  You'll 
either have to turn caching off, or use .sync/.expire to avoid stale caches.

Anyway, tell us how it goes.

   Ian

Re: [SQLObject] threading with spyce?

[Nick <ni...@dd...>]

Ian Bicking wrote:
> You'll have to be careful about caching, since SQLObject can't maintain 
> cache consistency on its own in a multi-process environment.  You'll 
> either have to turn caching off, or use .sync/.expire to avoid stale 
> caches.

Calling expire at the end of each request (or the beginning, I suppose) 
should take care of any persistency problems in mod_python, fastcgi, etc. 
At least it did for me.

Nick

Re: [SQLObject] threading with spyce?

[alexander s. <al...@an...>]

jws...@ra... wrote, at 28.05.2004 20:30:

> I'm considering using mod_python + spyce + sqlobject, but mod_python
> apparently needs to have python built without threading. Is that a
> deal-breaker for SO?

AFAIK mod_python v3 can use threaded python.  you just need to load the 
threads library in apache if it was built without threads.  on FreeBSD, 
this is done by adding the following lines to /usr/local/sbin/envvars:

   LD_PRELOAD=/usr/lib/libc_r.so  # or libpthread.so
   export LD_PRELOAD

best wishes,
alex.