使用 autbahn.asyncio.wamp 以非阻塞方式运行多个 ApplicationSession

Question

我正在尝试同时在 python 中运行两个autobahn.asyncio.wamp.ApplicationSessions。以前，我使用this post's answer 中建议的修改高速公路库来做到这一点。我现在 需要更专业的解决方案。

在谷歌上搜索了一段时间后，this post appeared quite promising，但使用 twisted 库，而不是 asyncio。我无法为autobahn 库的asyncio 分支找到类似的解决方案，因为它似乎没有使用Reactors。

我遇到的主要问题是 ApplicationRunner.run() 阻塞（这就是我之前将它外包给线程的原因），所以我不能在它之后再运行第二个 ApplicationRunner。

我确实需要同时访问 2 个 websocket 通道，而我似乎无法使用单个 ApplicationSession。

到目前为止我的代码：

from autobahn.asyncio.wamp import ApplicationSession
from autobahn.asyncio.wamp import ApplicationRunner
from asyncio import coroutine
import time


channel1 = 'BTC_LTC'
channel2 = 'BTC_XMR'

class LTCComponent(ApplicationSession):

    def onConnect(self):
        self.join(self.config.realm)

    @coroutine
    def onJoin(self, details):
        def onTicker(*args, **kwargs):
            print('LTCComponent', args, kwargs)

        try:
            yield from self.subscribe(onTicker, channel1)
        except Exception as e:
            print("Could not subscribe to topic:", e)

class XMRComponent(ApplicationSession):

    def onConnect(self):
        self.join(self.config.realm)

    @coroutine
    def onJoin(self, details):
        def onTicker(*args, **kwargs):
            print('XMRComponent', args, kwargs)

        try:
            yield from self.subscribe(onTicker, channel2)
        except Exception as e:
            print("Could not subscribe to topic:", e)

def main():
    runner = ApplicationRunner("wss://api.poloniex.com:443", "realm1", extra={})
    runner.run(LTCComponent)
    runner.run(XMRComponent) # <- is not being called


if __name__ == "__main__":

    try:
        main()
    except KeyboardInterrupt:
        quit()

    except Exception as e:
        print(time.time(), e)

我对@9​​87654338@ 库的了解有限，恐怕文档并没有太大改善我的情况。我在这里忽略了什么吗？一个函数、一个参数，可以让我组合我的组件或同时运行它们？

也许是与provided here 类似的解决方案，它实现了替代ApplicationRunner？

---

相关主题

Running two ApplicationSessions in twisted

Running Autobahn ApplicationRunner in Thread

Autobahn.wamp.ApplicationSession Source

Autobahn.wamp.Applicationrunner Source

---

根据要求，来自@stovfl 的回复使用multithreading 代码：

Exception in thread Thread-2:
Traceback (most recent call last):
  File "/home/nils/anaconda3/lib/python3.5/threading.py", line     914, in _bootstrap_inner
    self.run()
  File "/home/nils/git/tools/gemini_wss/t2.py", line 27, in run
    self.appRunner.run(self.__ApplicationSession)
  File "/home/nils/anaconda3/lib/python3.5/site-packages/autobahn-    0.14.1-py3.5.egg/autobahn/asyncio/wamp.py", line 143,     in run
    transport_factory = WampWebSocketClientFactory(create,         url=self.url,                 serializers=self.serializers)
  File "/home/nils/anaconda3/lib/python3.5/site-packages/autobahn-    0.14.1-py3.5.egg/autobahn/asyncio/websocket.py", line     319, in __init__
    WebSocketClientFactory.__init__(self, *args, **kwargs)
  File "/home/nils/anaconda3/lib/python3.5/site-packages/autobahn-    0.14.1-py3.5.egg/autobahn/asyncio/websocket.py", line     268, in __init__
    self.loop = loop or asyncio.get_event_loop()
  File "/home/nils/anaconda3/lib/python3.5/asyncio/events.py",     line 626, in get_event_loop
    return get_event_loop_policy().get_event_loop()
  File "/home/nils/anaconda3/lib/python3.5/asyncio/events.py",     line 572, in get_event_loop
    % threading.current_thread().name)
RuntimeError: There is no current event loop in thread 'Thread-2'.
Exception in thread Thread-1:
**Same as in Thread-2**
...
RuntimeError: There is no current event loop in thread 'Thread-1'.

Answer 1

正如我从traceback 看到的，我们只达到第 2 步，共 4 步

来自 asyncio 文档：
该模块提供了使用协程编写单线程并发代码的基础设施，通过套接字和其他资源多路复用 I/O 访问

所以我使用multithreading 放弃了我的第一个提案。
我可以想象以下三个选项：

1. 用multiprocessing 代替multithreading
2. 在asyncio loop 内使用coroutine 进行操作
3. 在channels 和def onJoin(self, details) 之间切换

---

第二个提案，第一个选项使用multiprocessing。
我可以启动两个asyncio loops，所以appRunner.run(...) 应该可以工作。

如果channel 是唯一不同的，您可以使用一个 class ApplicationSession。 如果您需要传递不同的class ApplicationSession，请将其添加到args=

class __ApplicationSession(ApplicationSession):
        # ...
        try:
            yield from self.subscribe(onTicker, self.config.extra['channel'])
        except Exception as e:
            # ...

import multiprocessing as mp
import time

def ApplicationRunner_process(realm, channel):
        appRunner = ApplicationRunner("wss://api.poloniex.com:443", realm, extra={'channel': channel})
        appRunner.run(__ApplicationSession)

if __name__ == "__main__":
    AppRun = [{'process':None, 'channel':'BTC_LTC'},
              {'process': None, 'channel': 'BTC_XMR'}]

    for app in AppRun:
        app['process'] =  mp.Process(target = ApplicationRunner_process, args = ('realm1', app['channel'] ))
        app['process'].start()
        time.sleep(0.1)

    AppRun[0]['process'].join()
    AppRun[1]['process'].join()

Answer 2

按照you linked for twisted 的方法，我设法通过异步设置获得了相同的行为start_loop=False

import asyncio
from autobahn.asyncio.wamp import ApplicationSession, ApplicationRunner

runner1 = ApplicationRunner(url, realm, extra={'cli_id': 1})
coro1 = runner1.run(MyApplicationSession, start_loop=False)

runner2 = ApplicationRunner(url, realm, extra={'cli_id': 2})
coro2 = runner2.run(MyApplicationSession, start_loop=False)

asyncio.get_event_loop().run_until_complete(coro1)
asyncio.get_event_loop().run_until_complete(coro2)
asyncio.get_event_loop().run_forever()

class MyApplicationSession(ApplicationSession):

    def __init__(self, cfg):
        super().__init__(cfg)
        self.cli_id = cfg.extra['cli_id']

   def onJoin(self, details):
        print("session attached", self.cli_id)