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artiq/artiq/protocols/asyncio_server.py

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1.6 KiB
Python

import asyncio
from copy import copy
class AsyncioServer:
"""Generic TCP server based on asyncio.
Users of this class must derive from it and define the
``_handle_connection_cr`` method and coroutine.
"""
def __init__(self):
self._client_tasks = set()
@asyncio.coroutine
def start(self, host, port):
"""Starts the server.
The user must call ``stop`` to free resources properly after this
method completes successfully.
This method is a `coroutine`.
:param host: Bind address of the server (see ``asyncio.start_server``
from the Python standard library).
:param port: TCP port to bind to.
"""
self.server = yield from asyncio.start_server(self._handle_connection,
host, port)
@asyncio.coroutine
def stop(self):
"""Stops the server.
"""
wait_for = copy(self._client_tasks)
for task in self._client_tasks:
task.cancel()
for task in wait_for:
try:
yield from asyncio.wait_for(task, None)
except asyncio.CancelledError:
pass
self.server.close()
yield from self.server.wait_closed()
del self.server
def _client_done(self, task):
self._client_tasks.remove(task)
def _handle_connection(self, reader, writer):
task = asyncio.Task(self._handle_connection_cr(reader, writer))
self._client_tasks.add(task)
task.add_done_callback(self._client_done)