Maybe someone else on this list can help you off-list? Teasing out the solution seems to be requiring a lot of back-and-forth.
On Thu, Aug 6, 2015 at 7:01 PM, Wellington Cordeiro <willy123...@gmail.com> wrote: > Maybe I'm using asyncio improperly but currently I have a class that I'm > writing that acts as the client. I'm trying to expose the API to it so that > I'm able to use it like > > client = ClientClass() > > try: > client.start() > > client.some_message_method() > > client.other_message_method() > except KeyboardInterrupt: > client.stop() > > Now the client, would be interacted with by other code that is synchronous > so that may be my problem and the calls to other methods may not come > immediately after start(), > so the start method would create the connection, send a logon message to > the server and then send the heartbeats at the set intervals (resetting the > interval when a different method is called.) > > With coroutines I was able to run them with loop.run_until_complete and > then return the response messages to the synchronous code. With tasks > though there doesn't seem to be a way. > > On Wednesday, August 5, 2015 at 11:27:01 AM UTC-6, Guido van Rossum wrote: >> >> You can't have it both ways. If it's a coroutine, you can't get its >> result in the callback. But that shouldn't be a problem -- you can just put >> any processing of the result you need in the coroutine. In effect, the only >> purpose of the callback then is to start the coroutine running. If you have >> an existing coroutine whose result you want to process, just wrap it in >> another coroutine which calls it (using yield from) and then does the >> processing. >> >> On Wed, Aug 5, 2015 at 7:21 PM, Wellington Cordeiro <willy...@gmail.com> >> wrote: >> >>> How do you unwrap the result of the coroutine wrapped in the task >>> though? >>> >>> On Wednesday, August 5, 2015 at 4:02:24 AM UTC-6, Guido van Rossum wrote: >>>> >>>> To start a coroutine from a callback, you wrap the coroutine in a Task. >>>> That's all. E.g. (untested) >>>> >>>> from asyncio import coroutine, get_event_loop >>>> >>>> @coroutine >>>> def coro(): >>>> ... >>>> yield from something() >>>> ... >>>> >>>> # callback >>>> def heartbeat(): >>>> get_event_loop().create_task(coro()) >>>> get_event_loop().call_later(n, heartbeat) >>>> >>>> heartbeat() # Get it all started >>>> >>>> On Wed, Aug 5, 2015 at 5:46 AM, Wellington Cordeiro <willy...@gmail.com >>>> > wrote: >>>> >>>>> I'm trying to add a system where a "heartbeat" message is sent to a >>>>> server every n seconds by my client, but I'm having trouble with the >>>>> loop.call_later or call_at methods. They use callbacks but I'm trying to >>>>> run a coroutine at the set interval without blocking. The conditions I'm >>>>> trying to work within are >>>>> >>>>> 1. countdown from n, when we reach zero send the heartbeat >>>>> 2. If a message is received from the server before we hit zero, reset >>>>> the timer >>>>> 3. If we send a different message before we hit zero, reset the timer >>>>> >>>>> I'm just not sure how to implement something like this with asyncio, I >>>>> tried using the threading.Timer class but since that creates another >>>>> thread >>>>> my client called the loop.stop() method before the interval and closed its >>>>> connection early. >>>>> >>>> >>>> >>>> >>>> -- >>>> --Guido van Rossum (python.org/~guido) >>>> >>> >> >> >> -- >> --Guido van Rossum (python.org/~guido) >> > -- --Guido van Rossum (python.org/~guido)
