Client not reconnecting after postgres restarting

• asyncpg version: asyncpg==0.18.3
• PostgreSQL version: PostgreSQL 10.6 on x86_64-pc-linux-gnu, compiled by gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516, 64-bit
• Do you use a PostgreSQL SaaS? If so, which? Can you reproduce
  the issue with a local PostgreSQL install?:
• Python version: 3.6
• Platform: Ubuntu
• Do you use pgbouncer?: no
• Did you install asyncpg with pip?: yes
• If you built asyncpg locally, which version of Cython did you use?:
• Can the issue be reproduced under both asyncio and
  uvloop?:

I'm using this library using Tortoise ORM but the trace back is going to the asyncpg library. so I hope you can share and help with this issue.

Describe the bug
ORM is not reconnect

To Reproduce

1. connect to postgres instance
2. restart postgres
3. try to execute query within the existing python process
4. see exception

Expected behavior

1. reconnect when postgres instance is up

Additional context
Trace-back1

Traceback (most recent call last):
  File \"/usr/lib/python3.6/asyncio/selector_events.py\", line 714, in _read_ready
    data = self._sock.recv(self.max_size)
ConnectionResetError: [Errno 104] Connection reset by peer
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/tortoise/models.py\", line 277, in create
    await instance.save(using_db=kwargs.get('using_db'))
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/tortoise/models.py\", line 221, in save
    await self._insert_instance(*args, **kwargs)
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/tortoise/models.py\", line 210, in _insert_instance
    ).execute_insert(self)
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/tortoise/backends/base/executor.py\", line 77, in execute_insert
    instance.id = await self.db.execute_insert(query, values)
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/tortoise/backends/asyncpg/client.py\", line 22, in wrapped
    return await func(self, query, *args)
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/tortoise/backends/asyncpg/client.py\", line 108, in execute_insert
    stmt = await connection.prepare(query)
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/asyncpg/connection.py\", line 403, in prepare
    return await self._prepare(query, timeout=timeout, use_cache=False)
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/asyncpg/connection.py\", line 408, in _prepare
    use_cache=use_cache)
  File \"/home/shlomy/PycharmProjects/playground/venv36/lib/python3.6/site-packages/asyncpg/connection.py\", line 329, in _get_statement
    statement = await self._protocol.prepare(stmt_name, query, timeout)
  File \"asyncpg/protocol/protocol.pyx\", line 163, in prepare
asyncpg.exceptions.ConnectionDoesNotExistError: connection was closed in the middle of operation"}

Trace back 2

connection is closed", "level": "error", "logger": "app.controller", "timestamp": "2019-05-23 12:30:55", "exception": "Traceback (most recent call last):
    result = await orm_class.filter(id__in=kwargs['devices_ids']).all()
  File \"/usr/local/lib/python3.7/site-packages/tortoise/queryset.py\", line 442, in _execute
    self.query, custom_fields=list(self._annotations.keys())
  File \"/usr/local/lib/python3.7/site-packages/tortoise/backends/base/executor.py\", line 28, in execute_select
    raw_results = await self.db.execute_query(query.get_sql())
  File \"/usr/local/lib/python3.7/site-packages/tortoise/backends/asyncpg/client.py\", line 22, in wrapped
    return await func(self, query, *args)
   File \"/usr/local/lib/python3.7/site-packages/tortoise/backends/asyncpg/client.py\", line 115, in execute_query
    return await connection.fetch(query)
  File \"/usr/local/lib/python3.7/site-packages/asyncpg/connection.py\", line 420, in fetch
    self._check_open()
  File \"/usr/local/lib/python3.7/site-packages/asyncpg/connection.py\", line 1147, in _check_open
    raise exceptions.InterfaceError('connection is closed')
asyncpg.exceptions._base.InterfaceError: connection is closed"}

从 asyncpg/connection.py 和 asyncpg/protocol/protocol.pyx 中展示的连接处理开始，然后重现报告的操作序列：连接、重启 PostgreSQL 并执行查询。将产生的 ConnectionDoesNotExistError 和 InterfaceError 与预期的重新连接行为进行比较；当 PostgreSQL 恢复运行后可以执行查询时，即表示完成。