[11u] RFR: 8216472: (se) Stack overflow during selection operation leads to crash (win)

[Alex Kashchenko]

Hi,

Please review the backport of JDK-8216472 to 11u:

Bug: https://bugs.openjdk.java.net/browse/JDK-8216472

Original review thread: 
https://mail.openjdk.java.net/pipermail/nio-dev/2019-October/006684.html

Original review thread (continuation): 
https://mail.openjdk.java.net/pipermail/nio-dev/2019-November/006777.html

Original change: https://hg.openjdk.java.net/jdk/jdk/rev/6bc29ebe053e

11u webrev: http://cr.openjdk.java.net/~akasko/jdk11u/8216472/webrev.00/

Please note, that original change, besides moving structs off the stack, 
additionally removes the logic for the case, when select() call returns 
SOCKET_ERROR:

  - starting here: 
https://hg.openjdk.java.net/jdk/jdk/rev/6bc29ebe053e#l2.58
  - explanation (point 1 there): 
https://mail.openjdk.java.net/pipermail/nio-dev/2019-October/006708.html

To stay on the safe side with LTS versions, this 11u backport keeps 
select() failure logic intact and allocates the space for 6 fd_set 
structs (instead of 3 in original change). It is proposed to have the 
change added to 11u in this "fix only" form. And, if necessary, to 
remove select() failure logic in a follow-up change.

Testing: 11u change in this form was included with Red Hat 
11.0.6-windows release and passed usual release testing.

-- 
-Alex