threading - race condition?

[castironpi at gmail.com]

On May 8, 5:45 pm, skunkwerk <skunkw... at gmail.com> wrote:
> i'm getting the wrong output for the 'title' attributes for this
> data.  the queue holds a data structure (item name, position, and list
> to store results in).  each thread takes in an item name and queries a
> database for various attributes.  from the debug statements the item
> names are being retrieved correctly, but the attributes returned are
> those of other items in the queue - not its own item.  however, the
> model variable is not a global variable... so i'm not sure what's
> wrong.
>
> i've declared a bunch of worker threads (100) and a queue into which
> new requests are inserted, like so:
>
> queue = Queue.Queue(0)
>  WORKERS=100
> for i in range(WORKERS):
>         thread = SDBThread(queue)
>         thread.setDaemon(True)
>         thread.start()
>
> the thread:
>
> class SimpleDBThread ( threading.Thread ):
>    def __init__ ( self, queue ):
>                 self.__queue = queue
>                 threading.Thread.__init__ ( self )
>    def run ( self ):
>                 while 1:
>                         item = self.__queue.get()
>                         if item!=None:
>                                 model = domain.get_item(item[0])
>                                 logger.debug('sdbthread item:'+item[0])
>                                 title = model['title']
>                                 scraped = model['scraped']
>                                 logger.debug("sdbthread title:"+title)
>
> any suggestions?
> thanks

I'll base this on terminology: if a model is in a brain (throughout
the known universe), and a dollar's a dollar, it may not pay to build
a computer out of brains.

If man arises as a tool-carrier, we will carry tools, not people.
Don't use Python to make people; make money, and not too much.  Pick a
wage and you might get somewhere.