import asyncio, socket, ssl, struct, threading

def serve(lsock):
    for _ in range(2):
        conn, _ = lsock.accept()
        conn.recv(65536)  # ClientHello
        # Reset the connection in the middle of the handshake.
        conn.setsockopt(socket.SOL_SOCKET, socket.SO_LINGER, struct.pack('ii', 1, 0))
        conn.close()

class Proto(asyncio.Protocol):
    lost = False
    def connection_lost(self, exc):
        self.lost = True

async def main():
    loop = asyncio.get_running_loop()
    ctx = ssl.create_default_context()
    lsock = socket.create_server(('127.0.0.1', 0))
    threading.Thread(target=serve, args=(lsock,), daemon=True).start()
    addr = lsock.getsockname()

    tr, proto = await loop.create_connection(Proto, *addr)
    try:
        await loop.start_tls(tr, proto, ctx, server_hostname='localhost')
    except OSError as exc:
        print('loop.start_tls():', repr(exc))
    await asyncio.sleep(1)
    print('connection_lost() called:', proto.lost)

    reader, writer = await asyncio.open_connection(*addr)
    try:
        await writer.start_tls(ctx, server_hostname='localhost')
    except OSError as exc:
        print('writer.start_tls():', repr(exc))
    writer.close()
    try:
        await asyncio.wait_for(writer.wait_closed(), 5)
    except TimeoutError:
        print('wait_closed() still pending after 5 seconds')
    except OSError as exc:
        print('wait_closed():', repr(exc))
    lsock.close()

asyncio.run(main())