Hi Jeremy,
lockedMonitors and lockedSynchronizers attribute are not optional if that's
the issue you try to resolve. I think the specification should be clarified.
ThreadInfo::from supports the three different versions for interoperability:
1. CompositeData for JDK 1.5 ThreadInfo with no lockedMonitors and
lockedSynchronizers attribute
2. CompositeData for JDK 6 ThreadInfo with lockedMonitors and
lockedSynchronizers
attributes
3. CompositeData for JDK 9 ThreadInfo with lockedMonitors and
lockedSynchronizers
attributes and with daemon and priority attribute.
JMX client can connect to a running VM in any version and get back a
proper ThreadInfo.
If ThreadInfo::from is called with a CompositeData containing daemon and
priority attribute but lockedMonitors and lockedSynchronizers attributes are
absent then the given CompositeData is invalid and IllegalArgumentException
should be thrown.
Does this help?
Mandy
On 2/15/18 4:46 PM, Jeremy Manson wrote:
Hi folks,
Been a long time! I'd like someone to do a code review. This is in
code I wrote a few years ago, and got wrong. At the time, David
Holmes, Staffan Larsen, and Mandy Chung reviewed it. It does mean
that people using ThreadInfo.from(CompositeData) may be getting the
wrong values out for ThreadInfo, so it is definitely worth fixing.
The patch below fixes the bug, but is a pretty questionable approach.
Better approaches happily considered.
Patch:
http://cr.openjdk.java.net/~jmanson/8198253/webrev.00/
<http://cr.openjdk.java.net/%7Ejmanson/8198253/webrev.00/>
Bug:
https://bugs.openjdk.java.net/browse/JDK-8198253
Thanks!
Jeremy
