Re: [rules-users] The effect of not using shadow facts

Chris, For the solution to work, it is important that a superclass or interface matches all the ObjectTypes in your rulebase that your final class (proxy) matches... I guess that is the case with JDK proxies, isn't it? []s Edson 2007/7/18, Chris West <crayzfishr(a)gmail.com&gt;: > > Edson, > > I downloaded and built the latest from the trunk of the repository. I > applied this new build toward my test case, and it seemed to fix the > problem. However, when I applied it to my real project, it still exhibits > the problem. If I discover more information about the problem I'll let you > know. > > Thanks, > Chris West > > On 7/17/07, Edson Tirelli < tirelli(a)post.com&gt; wrote: > > > > > > Chris, > > > > I found and developed an intermediate solution that shall work for > > your proxies. > > If it is not possible to create a shadow fact for a class that is > > asserted (because the class is final or whatever), the engine goes up in the > > class hierarchy, looking for a class or interface for which is possible to > > create the proxy, but that still matches all ObjectTypes available in the > > rule base matched by the original class. The analysis is a bit complex, > > specially because new rules with new object types can be dynamically added > > to the rule base, but I believe the solution will work for JDK proxies and > > the most common proxy frameworks out there, that usually don't proxy > > multiple unrelated interfaces at once. > > > > So, I ask you please to get latest snapshot from the repository and > > try it out for your use case and report back to the list the results, since > > seems there are a few other people using similar things. > > > > Thanks, > > Edson > > > > > > 2007/7/17, Chris West < crayzfishr(a)gmail.com&gt;: > > > > > > Is that still true if the equals() and hashcode() methods are only > > > based on the identity fields of the object (which cannot change)? > > > > > > -Chris West > > > > > > On 7/17/07, Mark Proctor <mproctor(a)codehaus.org&gt; wrote: > > > > > > > > you only need to use modifyRetract if the object is inserted. The > > > > reason for this is if you change field values on your facts we will not be > > > > able to remove them from our various internal hashmaps; thus the need to > > > > remove first prior to any changes, then make the changes and then insert it > > > > again. We can't allow users to just call update() as we have no idea what > > > > the old values where, thus we cannot find the objects in our hashmaps. > > > > > > > > Mark > > > > Chris West wrote: > > > > > > > > Mark, > > > > > > > > Using modifyRetract and modifyInsert seems to fix the problem (at > > > > least in my test case I finally created). I'll try this on my real code. > > > > > > > > My only concern here is that it puts the burden on the rule author > > > > to know whether things are being shadowed or not. For shadowing that is > > > > explicitly turned off this is ok. But for implicit non-shadowing based on a > > > > class being final, this is not at all obvious to the rule auther. > > > > > > > > Is there any way to have this hidden such that I can still call > > > > "update" but have it use "modifyRetract" and "modifyInsert" instead? > > > > > > > > Also, I'm curious why I have to call modifyRetract before I start > > > > modifing the object, since the engine does not know about my modifications > > > > anyway until I call update or modifyInsert? By the way, I was unable to use > > > > the block setter approach in the rule consequence due to not having set > > > > methods for modifying my objects. > > > > > > > > Thanks, > > > > -Chris West > > > > > > > > On 7/17/07, Mark Proctor <mproctor(a)codehaus.org > wrote: > > > > > > > > > > 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=tirell... > > > > > [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 > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > rules-users mailing list > > > > > rules-users(a)lists.jboss.org > > > > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > > > > > > > > ------------------------------ > > > > > > > > _______________________________________________ > > > > rules-users mailing list > > > > rules-users(a)lists.jboss.org > > > > > > > > > > > > > > > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > > > > > > > > > > _______________________________________________ > > > > rules-users mailing list > > > > rules-users(a)lists.jboss.org > > > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > > > > > > > > _______________________________________________ > > > rules-users mailing list > > > rules-users(a)lists.jboss.org > > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > > > > > > -- > > Edson Tirelli > > Software Engineer - JBoss Rules Core Developer > > Office: +55 11 3529-6000 > > Mobile: +55 11 9287-5646 > > JBoss, a division of Red Hat @ www.jboss.com > > > > _______________________________________________ > > rules-users mailing list > > rules-users(a)lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- Edson Tirelli Software Engineer - JBoss Rules Core Developer Office: +55 11 3529-6000 Mobile: +55 11 9287-5646 JBoss, a division of Red Hat @ www.jboss.com _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users