Hi,

I have finally gained a tiny bit of control (and maybe even some competency) in using the DROOLs language operators ‘no-loop’ and ‘lock-on-active’ as a basis for controlling rule set firing behavior in response to Fact mutation events (during consequence processing).

I now want to (competently!) use DROOLs language tactics that give me ever finer grained control over managing rule set firing behavior on Fact mutation events.  Specifically, I want to be able to implement some form of ‘Guarded entry/block’ controls. 

E.g. let’s say I have a Fact  (InsertedFactPOJO) that I insert into the KS and want to have its ‘fireAllRules()’  AgendaSet(s) renedered in exact incremental ordinal stages and in perfect isolation.  To do this, I am testing the inclusion of a ‘countdownLatch’ Semaphore reference as a Fact member (initialized to N=`total rule count` value).  I then use this to ‘Guard’ individual rule entry, by generating an explicit predicate participant

(InsertedFactPOJO(countdownLatch             == i) )

@ each ith Rule producedby my template.

Is this approach a valid/sound/complete way to implement ‘Guarded entry/block’ controls in DROOLs?  Is there a better way?

As always, my sincerest gratitude to this community for its generosity (and its genius).

Ben

package com.ms.fast.triclear.eligibility.rules.drools_community.questions.posted;

import com.ms.fast.triclear.eligibility.InsertedFactPOJO;  

//fact:(backed by Class 'InsertedFactPOJO'  has

//- 'countdownLatch' (Semaphore) member

//- 'aList' (List)member

rule "RULE_ALL_RULES_HAVE_FIRED_ONCE_ORDINALLY"

when

    fact:InsertedFactPOJO()

    InsertedFactPOJO(countdownLatch == 0)

then

    System.out.format("\tALL RULES have fired *EXACTLY* once, *EXACTLY* ordinally. "+

                    " fact.countdownLatch=%d \n\t fact.aList=%s\n\n",

                    fact.countdownLatch,

                    fact.aList.toString());

end

rule "RULE_3"

    when

        fact:InsertedFactPOJO()

        InsertedFactPOJO(countdownLatch             == 3)

        //bunch of other L-Value PREDICATES      

    then

        System.out.format("\t %20.20s"+

                         " \t(DROOLS agenda: consequence fired for L-value predicate match @RULE="+

                      "3"+" -- fact.countDownLatch=%d)\n", "Rule 3",fact.countdownLatch);

        modify (fact) {

            countdownLatch = fact.countdownLatch - 1,

            aList.add("Rule 3 pattern-match event added to POJO 'aList' field");

        }     

end

rule "RULE_2"

    when

        fact:InsertedFactPOJO()

        InsertedFactPOJO(countdownLatch             == 2)

        //bunch of other L-Value PREDICATES      

    then

        System.out.format("\t %20.20s"+

                         " \t(DROOLS agenda: consequence fired for L-value predicate match @RULE="+

                      "2"+" -- fact.countDownLatch=%d)\n", "Rule 2",fact.countdownLatch);

        modify (fact) {

            countdownLatch = fact.countdownLatch - 1,

            aList.add("Rule 2 pattern-match event added to POJO 'aList' field");

        }     

end

rule "RULE_1"

    when

        fact:InsertedFactPOJO()

        InsertedFactPOJO(countdownLatch             == 1)

        //bunch of other L-Value PREDICATES      

    then

        System.out.format("\t %20.20s"+

                         " \t(DROOLS agenda: consequence fired for L-value predicate match @RULE="+

                      "1"+" -- fact.countDownLatch=%d)\n", "Rule 1",fact.countdownLatch);

        modify (fact) {

            countdownLatch = fact.countdownLatch - 1,

            aList.add("Rule 1 pattern-match event added to POJO 'aList' field");

        }     

end

Ben D Cotton III
Morgan Stanley & Co.
OTC Derivatives Clearing Technology
1221 AOTA Rockefeller Ctr - Flr 27
New York, NY 10020
(212)762.9094
ben.cotton@ms.com