[13] RFR: 8216478: Cleanup HttpResponseImpl back reference to HttpConnection

[Daniel Fuchs]

Hi,

Please find below a fix for:

8216478: Cleanup HttpResponseImpl back reference to HttpConnection
https://bugs.openjdk.java.net/browse/JDK-8216478

webrev:
http://cr.openjdk.java.net/~dfuchs/webrev_8216478/webrev.00/

HttpResponseImpl keeps an internal hard reference to the Exchange
and HttpConnection objects which were involved in the exchange
through which the response was received.
This has the inconvenience of pinning a number of auxiliary
internal objects in memory until all references to the HttpResponse
is released by the application code.

These internal references are only useful in the case of the
initial request that establishes a WebSocket connection.
This small patch proposes to only keep them in the
case where the request is a WebSocket connect request.

This should avoid pinning these objects in memory until the
reference to the HttpResponseImpl is released by user code
for the regular case where no WebSocket is involved.

There's no additional non-regression test - but I have verified
that all existing tests are still passing.

best regards,

-- daniel