运行时错误：事件循环已关闭

Question

我试图将 pyppeteer 和 quart 结合起来，但由于启动浏览器需要花费很多时间，我宁愿全局处理它（使用异步锁），这似乎意味着我需要手动处理清理。这是我的最小代码示例：

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#!/usr/bin/env python3\n\nimport asyncio\nimport atexit\nimport pyppeteer\n\nfrom quart import Quart, Response, request\n\napp = Quart(__name__)\nbrowser = asyncio.get_event_loop().run_until_complete(pyppeteer.launch())\n\nasync def cleanup_async():\n    await browser.quit()\n\n@atexit.register\ndef cleanup():\n    asyncio.get_event_loop().run_until_complete(cleanup_async())\n

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问题如下：

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[22:26:53] \xe2\x9e\x9c  strokes git:(async_browser) \xe2\x9c\x97  % QUART_APP=/tmp/quart_cleanup.py timeout 10s quart run -h 0.0.0.0\nRunning on http://0.0.0.0:5000 (CTRL + C to quit)\nTraceback (most recent call last):\n  File "/home/d33tah/virtualenv-py3/bin/quart", line 11, in <module>\n    sys.exit(main())\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/quart/cli.py", line 208, in main\n    cli.main(args=args, prog_name=name)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/quart/cli.py", line 152, in main\n    return super().main(*args, **kwargs)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 697, in main\n    rv = self.invoke(ctx)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 1066, in invoke\n    return _process_result(sub_ctx.command.invoke(sub_ctx))\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 895, in invoke\n    return ctx.invoke(self.callback, **ctx.params)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 535, in invoke\n    return callback(*args, **kwargs)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/decorators.py", line 64, in new_func\n    return ctx.invoke(f, obj, *args[1:], **kwargs)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 535, in invoke\n    return callback(*args, **kwargs)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/quart/cli.py", line 165, in run_command\n    use_reloader=debug,\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/quart/serving/__init__.py", line 146, in run_app\n    loop.run_until_complete(_observe_changes())\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 454, in run_until_complete\n    self.run_forever()\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 421, in run_forever\n    self._run_once()\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 1371, in _run_once\n    event_list = self._selector.select(timeout)\n  File "/usr/lib/python3.6/selectors.py", line 445, in select\n    fd_event_list = self._epoll.poll(timeout, max_ev)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/pyppeteer/launcher.py", line 146, in _close_process\n    asyncio.get_event_loop().run_until_complete(self.killChrome())\n  File "/usr/lib/python3.6/asyncio/coroutines.py", line 84, in debug_wrapper\n    return CoroWrapper(gen, None)\n  File "/usr/lib/python3.6/asyncio/coroutines.py", line 92, in __init__\n    self.gen = gen\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/pyppeteer/launcher.py", line 146, in _close_process\n    asyncio.get_event_loop().run_until_complete(self.killChrome())\nRuntimeError: coroutine wrapper <function debug_wrapper at 0x7f29878938c8> attempted to recursively wrap <code object killChrome at 0x7f2985e6edb0, file "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/pyppeteer/launcher.py", line 188>\nError in atexit._run_exitfuncs:\nTraceback (most recent call last):\n  File "/tmp/quart_cleanup.py", line 17, in cleanup\n    asyncio.get_event_loop().run_until_complete(cleanup_async())\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 443, in run_until_complete\n    self._check_closed()\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 357, in _check_closed\n    raise RuntimeError(\'Event loop is closed\')\nRuntimeError: Event loop is closed\nError in atexit._run_exitfuncs:\nTraceback (most recent call last):\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/pyppeteer/launcher.py", line 146, in _close_process\n    asyncio.get_event_loop().run_until_complete(self.killChrome())\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 443, in run_until_complete\n    self._check_closed()\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 357, in _check_closed\n    raise RuntimeError(\'Event loop is closed\')\nRuntimeError: Event loop is closed\nsys:1: RuntimeWarning: coroutine \'Launcher.killChrome\' was never awaited\nException ignored in: <object repr() failed>\nTraceback (most recent call last):\n  File "/usr/lib/python3.6/asyncio/coroutines.py", line 182, in __del__\n    msg = \'%r was never yielded from\' % self\n  File "/usr/lib/python3.6/asyncio/coroutines.py", line 99, in __repr__\n    coro_repr = _format_coroutine(self)\n  File "/usr/lib/python3.6/asyncio/coroutines.py", line 301, in _format_coroutine\n    func = coro.func\nAttributeError: \'CoroWrapper\' object has no attribute \'func\'\nTask was destroyed but it is pending!\ntask: <Task pending coro=<Connection._recv_loop() running at /home/d33tah/virtualenv-py3/lib/python3.6/site-packages/pyppeteer/connection.py:54> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7f2985bd5828>()] created at /usr/lib/python3.6/asyncio/base_events.py:275>>\nException ignored in: <coroutine object Connection._recv_loop at 0x7f2985b39780>\nTraceback (most recent call last):\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/pyppeteer/connection.py", line 59, in _recv_loop\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/websockets/client.py", line 390, in __aexit__\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/websockets/protocol.py", line 370, in close\n  File "/usr/lib/python3.6/asyncio/tasks.py", line 342, in wait_for\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 543, in call_later\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 553, in call_at\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 357, in _check_closed\nRuntimeError: Event loop is closed\nTask was destroyed but it is pending!\ntask: <Task pending coro=<WebSocketCommonProtocol.transfer_data() running at /home/d33tah/virtualenv-py3/lib/python3.6/site-packages/websockets/protocol.py:496> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7f2985b5f258>()] created at /usr/lib/python3.6/asyncio/base_events.py:275> cb=[<TaskWakeupMethWrapper object at 0x7f2985bd5e58>(), _wait.<locals>._on_completion() at /usr/lib/python3.6/asyncio/tasks.py:380]>\nTask was destroyed but it is pending!\ntask: <Task pending coro=<WebSocketCommonProtocol.close_connection() running at /home/d33tah/virtualenv-py3/lib/python3.6/site-packages/websockets/protocol.py:711> wait_for=<Task pending coro=<WebSocketCommonProtocol.transfer_data() running at /home/d33tah/virtualenv-py3/lib/python3.6/site-packages/websockets/protocol.py:496> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7f2985b5f258>()] created at /usr/lib/python3.6/asyncio/base_events.py:275> cb=[<TaskWakeupMethWrapper object at 0x7f2985bd5e58>(), _wait.<locals>._on_completion() at /usr/lib/python3.6/asyncio/tasks.py:380]>>\nException ignored in: <generator object WebSocketCommonProtocol.close_connection at 0x7f2985b39b48>\nTraceback (most recent call last):\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/websockets/protocol.py", line 741, in close_connection\n  File "/usr/lib/python3.6/asyncio/streams.py", line 306, in close\n  File "/usr/lib/python3.6/asyncio/selector_events.py", line 622, in close\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 574, in call_soon\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 357, in _check_closed\nRuntimeError: Event loop is closed\nTask was destroyed but it is pending!\nsource_traceback: Object created at (most recent call last):\n  File "/home/d33tah/virtualenv-py3/bin/quart", line 11, in <module>\n    sys.exit(main())\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/quart/cli.py", line 208, in main\n    cli.main(args=args, prog_name=name)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/quart/cli.py", line 152, in main\n    return super().main(*args, **kwargs)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 697, in main\n    rv = self.invoke(ctx)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 1066, in invoke\n    return _process_result(sub_ctx.command.invoke(sub_ctx))\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 895, in invoke\n    return ctx.invoke(self.callback, **ctx.params)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 535, in invoke\n    return callback(*args, **kwargs)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/decorators.py", line 64, in new_func\n    return ctx.invoke(f, obj, *args[1:], **kwargs)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/click/core.py", line 535, in invoke\n    return callback(*args, **kwargs)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/quart/cli.py", line 165, in run_command\n    use_reloader=debug,\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/quart/serving/__init__.py", line 146, in run_app\n    loop.run_until_complete(_observe_changes())\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 454, in run_until_complete\n    self.run_forever()\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 421, in run_forever\n    self._run_once()\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 1418, in _run_once\n    handle._run()\n  File "/usr/lib/python3.6/asyncio/events.py", line 127, in _run\n    self._callback(*self._args)\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/pyppeteer/connection.py", line 54, in _recv_loop\n    resp = await self.connection.recv()\n  File "/home/d33tah/virtualenv-py3/lib/python3.6/site-packages/websockets/protocol.py", line 305, in recv\n    self.messages.get(), loop=self.loop)\ntask: <Task pending coro=<Queue.get() running at /usr/lib/python3.6/asyncio/queues.py:167> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x7f2985b5f228>()] created at /usr/lib/python3.6/asyncio/base_events.py:275> cb=[_wait.<locals>._on_completion() at /usr/lib/python3.6/asyncio/tasks.py:380] created at /home/d33tah/virtualenv-py3/lib/python3.6/site-packages/websockets/protocol.py:305>\nException ignored in: <generator object Queue.get at 0x7f2985810c50>\nTraceback (most recent call last):\n  File "/usr/lib/python3.6/asyncio/queues.py", line 169, in get\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 574, in call_soon\n  File "/usr/lib/python3.6/asyncio/base_events.py", line 357, in _check_closed\nRuntimeError: Event loop is closed\n

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Answer 1

我使用@app.before_serving和解决了这个问题@app.after_serving。