On Sep 16, 2010, at 10:44 PM, mdipierro wrote:
>
> Jonathan,
>
> I misunderstood your problem. You should not spawn threads from a
> web2py app. This is not just because the current routing mechanism
> does not support it. This is a very general with all web applications
> because threads are managed by the web server which starts/stops and
> kills them. If your thread spawns a new thread and the parent is
> killed by the web server you may end up with a memory leak.
>
> Please explain what you are trying to achieve, perhaps show us some
> code, and I am sure there is another way.
Here's a quick patch to rewrite.filter_out that should fix the problem for
URL() as long as app-specific routes are not in use:
def filter_out(url, e=None):
"called from html.URL to rewrite outgoing URL"
+ if not hasattr(thread, 'routes'):
+ select() # ensure thread.routes is set (for application threads)
if thread.routes.routes_out:
items = url.split('?', 1)
if e:
Massimo, this will be a little confusing, since there are two Jonathans on this
(message) thread, and both of us are using application threads.
Here's my case:
The application is a manager for a collection of servers, from tens to possibly
hundreds. On the central management page, I create a table that summarizes the
status of the servers. I get the status by sending an xmlrpc query to each
server, and the response can take several seconds (say 2-10).
Because serializing these requests can take too long, I create a thread per
server to make the query and wait for the response. CPU time for such a request
is nil, so all the threads complete in approximately the time for the slowest
one.
The code is very simple and very clean.
No doubt I could accomplish something like it with Ajax, and effectively a
request thread for each server. But I hesitate to rely on the web server's
thread pool, assuming it has one big enough, and an Ajax solution wouldn't be
so straightforward, I don't think.
>
> Massimo
>
> On Sep 16, 2:26 pm, "Jonathan Z." <[email protected]> wrote:
>> I'm kicking off a threaded process. As part of the "run" method, I'm
>> calling: env("application", import_models=True) in order to work with
>> the web2py environment inside the context of my thread. As a result,
>> models are parsed and the following exception is raised:
>>
>> Traceback (most recent call last):
>> File ".../web2py/gluon/restricted.py", line 188, in restricted
>> exec ccode in environment
>> File "applications/app/models/db.py", line 32, in <module>
>> auth = Auth(globals(), db)
>> File ".../web2py/gluon/tools.py", line 804, in __init__
>> self.settings.login_url = self.url('user', args='login')
>> File ".../web2py/gluon/tools.py", line 762, in url
>> f=f, args=args, vars=vars)
>> File ".../web2py/gluon/html.py", line 228, in _URL
>> return URL(*args, **kwargs)
>> File ".../web2py/gluon/html.py", line 206, in URL
>> return XML(rewrite.filter_out(url, env))
>> File ".../web2py/gluon/rewrite.py", line 183, in filter_out
>> if thread.routes.routes_out:
>> AttributeError: 'thread._local' object has no attribute 'routes'
>>
>> As soon as URLs are parsed during Auth initialization, the thread hits
>> a case where an invalid "routes" attribute is dereferenced within
>> rewrite.py. My threaded code was working until the following change
>> was rolled into 1.84.x: "moved DAL and routes to thread.local"
