[8u] RFR: 8215355: Object monitor deadlock with no threads holding the monitor (using jemalloc 5.1)

[Severin Gehwolf]

Hi,

Could I please get a review of this OpenJDK 8u backport? The patch is
in Oracle JDK 8u and we should get it backported for parity. It doesn't
apply cleanly, but is rather trivial to be fixed up manually. The hunk
in thread.hpp didn't apply since JDK-8139864[1] is not in OpenJDK 8u.
Thus, changed '>=' to '>' manually in thread.hpp.

Bug: https://bugs.openjdk.java.net/browse/JDK-8215355
webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8215355/01/webrev/
Original change: https://hg.openjdk.java.net/jdk/jdk/rev/189f47d990b5

Testing: Reproducer in JDK-8215355 (fails prior/passes after), tier1 tests.

Thoughts?

Thanks,
Severin