RFR (testbug): 8216562: UnknownBodyLength sometimes fails due to "Connection reset by peer"

[Daniel Fuchs]

Hi,

Please find below a fix for:

8216562: UnknownBodyLength sometimes fails due to
          "Connection reset by peer"
https://bugs.openjdk.java.net/browse/JDK-8216562

webrev:
http://cr.openjdk.java.net/~dfuchs/webrev_8216562/webrev.00/

My previous attempt at at fixing this test proved
unsuccessful, as I was still seeing some very infrequent
failures - caused by connection reset, with https.

The present fix does 3 things:

1. increase the SO_LINGER time, to reduce the risk of
    generating a reset (1s -> 30s).
2. keep the accepted socket around (server side) until the
    client finishes - to avoid it to be prematurely gc'ed
    and its file descriptor released.
3. calls shutdownOutput() - but delay closing the socket
    until the client finishes. This should also reduce the
    risk of generating a reset.

with this, I haven't been able to reproduce the issue yet.
I believe it does fix it - though I'm afraid only time will
tell...

best regards,

-- daniel