`_SSLProtocolTransport` keeps reference to protocol after close

[kumaraditya303]

_SSLProtocolTransport keeps reference to protocol after close. It leads to reference cyeles between the transport and the protocol and is bad for gc. Clearing this is better as it frees up the memory immediately without waiting for the gc. This causes memory leaks in some cases as if an exception occurs the deallocation is delayed even further as tracebacks keeps ref to frame and frame keeps locals alive.

cpython/Lib/asyncio/sslproto.py

Lines 102 to 111 in 8d57423

	def close(self):
	"""Close the transport.
	Buffered data will be flushed asynchronously. No more data
	will be received. After all buffered data is flushed, the
	protocol's connection_lost() method will (eventually) called
	with None as its argument.
	"""
	self._closed = True
	self._ssl_protocol._start_shutdown()

Linked PRs

• gh-98539: Make _SSLTransportProtocol.abort() safe to call when closed #104474
• [3.11] gh-98539: Make _SSLTransportProtocol.abort() safe to call when closed (GH-104474) #104485

[kumaraditya303]

Fixed by #98540