Le 28 janv. 2016 22:52, "Ian Kelly" <ian.g.ke...@gmail.com> a écrit : > > On Thu, Jan 28, 2016 at 2:23 PM, Maxime S <maxischm...@gmail.com> wrote: > > > > 2016-01-28 17:53 GMT+01:00 Ian Kelly <ian.g.ke...@gmail.com>: > >> > >> On Thu, Jan 28, 2016 at 9:40 AM, Frank Millman <fr...@chagford.com> wrote: > >> > >> > The caller requests some data from the database like this. > >> > > >> > return_queue = asyncio.Queue() > >> > sql = 'SELECT ...' > >> > request_queue.put((return_queue, sql)) > >> > >> Note that since this is a queue.Queue, the put call has the potential > >> to block your entire event loop. > >> > > > > Actually, I don't think you actually need an asyncio.Queue. > > > > You could use a simple deque as a buffer, and call fetchmany() when it is > > empty, like that (untested): > > True. The asyncio Queue is really just a wrapper around a deque with > an interface designed for use with the producer-consumer pattern. If > the producer isn't a coroutine then it may not be appropriate. > > This seems like a nice suggestion. Caution is advised if multiple > cursor methods are executed concurrently since they would be in > different threads and the underlying cursor may not be thread-safe. > -- > https://mail.python.org/mailman/listinfo/python-list
Indeed, the run_in_executor call should probably protected by an asyncio.Lock. But it is a pretty strange idea to call two fetch*() method concurrently anyways. -- https://mail.python.org/mailman/listinfo/python-list