If you do not have shadow facts you cannot use the update() method, it
will leave the working memory corrupted. Instead you must manage this
yourself, before you change any values on the object you must call
modifyRetract() and after you hvae finished your changes ot hte object
call modifyInsert() - luckily if you are doing this in the consequence
you can use the MVEL modify keyword combined with the block setter and
it does this for you:
modify ( person ) { age += 1, location = "london" }
Mark
Chris West wrote:
Hello,
With prior versions of JBoss Rules (3.0.5) I have been using JDK
generated dynamic proxies as facts, and they have been working fine.
However, after upgrading to JBoss Rules 4.0.0MR3, I cannot seem to get
the dynamic proxies to work as facts. It seems that even though a
rule fires that changes a field on the proxy, a second rule that
should not be activated after the update still fires.
According to the JDK javadoc documentation, dynamic proxies are
created as final. My assumption is that JBoss Rules is not creating
Shadow facts for these since they are final. After reading the JIRA
at
http://jira.jboss.com/jira/browse/JBRULES-960, I now am questioning
what the effect of not using shadow facts is on the engine. The
relevant part of that is:
"The problem is that SpringAOP is generating a proxy whose methods
equals() and hashCode() are "final". As drools must either override
these methods in the shadow proxy or not shadow the fact at all, I'm
disabling shadow proxy generation for this use case.
It is really important to note that if you are asserting SpringAOP
proxies as facts into the working memory, you will not be able to
change any field value whose field is constrained in rules or you may
incur in a memory leak and non-deterministic behavior by the rules
engine. Unfortunately there is nothing we can do about, since when
SpringAOP makes the methods equals and hashcode final, we can't
override them anymore and as so, we can't shadow them."
[ Show » <
http://jira.jboss.com/jira/browse/JBRULES-960> ]
Edson Tirelli
<
http://jira.jboss.com/jira/secure/ViewProfile.jspa?name=tirelli>
[02/Jul/07 03:29 PM] The problem is that SpringAOP is generating a
proxy whose methods equals() and hashCode() are "final". As drools
must either override these methods in the shadow proxy or not shadow
the fact at all, I'm disabling shadow proxy generation for this use
case. It is really important to note that if you are asserting
SpringAOP proxies as facts into the working memory, you will not be
able to change any field value whose field is constrained in rules or
you may incur in a memory leak and non-deterministic behavior by the
rules engine. Unfortunately there is nothing we can do about, since
when SpringAOP makes the methods equals and hashcode final, we can't
override them anymore and as so, we can't shadow them.
Although I'm not using SpringAOP, I believe my facts are not being
shadowed.
Is it true that not using shadow facts may lead to non-deterministic
behavior? Prior to shadow facts, the engine seemed to handle it. Any
chance of reverting back to the old style of truth maintenance in the
case of not using shadow facts.
I apologize if I'm not on the right track here. My only test case for
my problem is the entire application right now, so I cannot offer it
for discussion. Any advice would be greatly appreciated.
Thanks,
-Chris West
------------------------------------------------------------------------
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users