Based on discussions around 8010815 I withdraw my comments on this change.
I'll leave it to others to review this.
David
On 4/06/2013 7:51 PM, Jaroslav Bachorik wrote:
On 05/29/2013 04:08 AM, David Holmes wrote:
On 28/05/2013 11:13 PM, Jaroslav Bachorik wrote:
Please, review the fix for JDK-8002307.
The fix assures the immutability by cloning the provided arrays in the
constructor and then cloning them again in the getters.
This fix has the same problems/issues as 8010815:
http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-May/016930.html
It is not obvious that the specification of these classes allows for
cloning, nor that people using this won't expect external changes to the
arrays to be passed through.
The use of "immutability" in the spec for MBeanInfo is ambiguous. It
might just mean that the references to the arrays never change. It need
not imply/require "deep" immutability.
Hm, I see. While the implicit mutability is an obvious error as it
allows external parties to modify the MBeanInfo contents without proper
checks and without sending the proper notifications there is no word
about the provided info arrays being immutable either in javadoc or the
JMX spec.
If we want to do this aggressive defensive copying to placate FindBugs
(which is simply flagging things to pay attention to, not that are
necessarily incorrect) then I think spec updates may also be required.
We wouldn't be doing this only to placate FindBugs - it is rather easy
to break JMX by eg. nullifying a slot of MBeanAttributeInfo[] array that
was previously used to build a ModelMBeanInfoSupport.
If the spec is to be updated we should also rev the JSR 3. I'm just
wandering whether it is really worth to address this issue :/
-JB-
David
-----
The constructors are fixed in the javax/management/MBeanInfo.java and
the arrays used in getters are cloned using an already existing
functionality in the same class.
http://cr.openjdk.java.net/~jbachorik/8002307/webrev.01
Thanks,
-JB-
