12:42 p.m.
Hi,
while working further on our drools integration we came across an odd
exception when removing a particular rule:
java.lang.IllegalArgumentException: Cannot remove a sink, when the list of sinks is null
at org.drools.reteoo.ObjectSource.removeObjectSink(ObjectSource.java:159)
at
org.drools.reteoo.RightInputAdapterNode.doRemove(RightInputAdapterNode.java:217)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at org.drools.reteoo.BetaNode.doRemove(BetaNode.java:275)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at org.drools.reteoo.BetaNode.doRemove(BetaNode.java:280)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at org.drools.reteoo.RuleTerminalNode.doRemove(RuleTerminalNode.java:387)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at org.drools.reteoo.ReteooBuilder.removeRule(ReteooBuilder.java:237)
at org.drools.reteoo.ReteooRuleBase.removeRule(ReteooRuleBase.java:371)
at org.drools.common.AbstractRuleBase.removeRule(AbstractRuleBase.java:746)
While stepping through the code it looked like the network was corrupt (there was indeed
no
sinks on the ObjectSource, but the node calling removeObjectSink was still linked to it
and claiming it as source).
The rule itself contains multiple NotNodes, checking a condition that looks like this:
not(not(Foo.v = X) and not(Foo.v = Y))
I could track this down to some sort of "loop" in the rete that triggers this
when the outer
not node is removed.
When removing BetaNode#doRemove() first walks along 'rightInput':
this.rightInput.remove( context,
builder,
this,
workingMemories );
and eventually _in that call_ it also hits a node that is the direct 'leftInput'
of the original beta node.
The removal marks that node as visited in the removal context, and when the
'rightInput.remove' returns to the
beta node it does not visit the leftInput due to this condition in BetaNode#doRemove():
if ( !context.alreadyVisited( this.leftInput ) ) {
this.leftInput.remove( context,
builder,
this,
workingMemories );
}
In other words: before the remove the BetaNode had another node that was both referenced
directly as 'leftInput',
as well as an input to the 'rightInput'.
The first removal of the rule "worked", and no exceptions happened. But: any
further attempt to re-add the same rule and remove
it again lead to the exception above.
I was able to fix it with the attached patch, reproduced here:
+ boolean needRemoveFromLeft = !context.alreadyVisited( this.leftInput );
this.rightInput.remove( context,
builder,
this,
workingMemories );
- if ( !context.alreadyVisited( this.leftInput ) ) {
+ if ( needRemoveFromLeft ) {
this.leftInput.remove( context,
builder,
this,
workingMemories );
}
With this patch applied I could add/delete/add the particular rule repeatedly without
problems.
The attached patch also adds an assert in ObjectSource#removeObjectSink(): when removing a
sink from an object source with
only one sink the sink was unconditionally replaced with an empty sink, although the
argument ObjectSink could be a different
sink than the one in the ObjectSource. For CompositeObjectSinkAdapters this case is
checked, but not for single sinks.
I originally suspected that place to be responsible for the problem I observed but the
assertion never fired in my tests.
Should I open a JIRA issue? Unfortunately I cannot provide a DRL to reproduce the issue,
but I could
try dumping the rulebase if that would help.
Regards,
--
Andreas
--
Never attribute to malice that which can be adequately explained by
stupidity. -- Hanlon's Razor
noon
Hi Andreas,
Yes, please open a JIRA and attach your patch. I will try to reproduce
and create a test case from your description, but sometimes it would be
faster if you could provide a dumbed down or obfuscated version of the rule
you are using that is causing the problem...
Thanks,
Edson
2010/3/29 Andreas Kohn <andreas.kohn(a)fredhopper.com>
Hi,
while working further on our drools integration we came across an odd
exception when removing a particular rule:
java.lang.IllegalArgumentException: Cannot remove a sink, when the list of
sinks is null
at
org.drools.reteoo.ObjectSource.removeObjectSink(ObjectSource.java:159)
at
org.drools.reteoo.RightInputAdapterNode.doRemove(RightInputAdapterNode.java:217)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at org.drools.reteoo.BetaNode.doRemove(BetaNode.java:275)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at org.drools.reteoo.BetaNode.doRemove(BetaNode.java:280)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at
org.drools.reteoo.RuleTerminalNode.doRemove(RuleTerminalNode.java:387)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at
org.drools.reteoo.ReteooBuilder.removeRule(ReteooBuilder.java:237)
at
org.drools.reteoo.ReteooRuleBase.removeRule(ReteooRuleBase.java:371)
at
org.drools.common.AbstractRuleBase.removeRule(AbstractRuleBase.java:746)
While stepping through the code it looked like the network was corrupt
(there was indeed no
sinks on the ObjectSource, but the node calling removeObjectSink was still
linked to it
and claiming it as source).
The rule itself contains multiple NotNodes, checking a condition that looks
like this:
not(not(Foo.v = X) and not(Foo.v = Y))
I could track this down to some sort of "loop" in the rete that triggers
this when the outer
not node is removed.
When removing BetaNode#doRemove() first walks along 'rightInput':
this.rightInput.remove( context,
builder,
this,
workingMemories );
and eventually _in that call_ it also hits a node that is the direct
'leftInput' of the original beta node.
The removal marks that node as visited in the removal context, and when the
'rightInput.remove' returns to the
beta node it does not visit the leftInput due to this condition in
BetaNode#doRemove():
if ( !context.alreadyVisited( this.leftInput ) ) {
this.leftInput.remove( context,
builder,
this,
workingMemories );
}
In other words: before the remove the BetaNode had another node that was
both referenced directly as 'leftInput',
as well as an input to the 'rightInput'.
The first removal of the rule "worked", and no exceptions happened. But:
any further attempt to re-add the same rule and remove
it again lead to the exception above.
I was able to fix it with the attached patch, reproduced here:
+ boolean needRemoveFromLeft = !context.alreadyVisited(
this.leftInput );
this.rightInput.remove( context,
builder,
this,
workingMemories );
- if ( !context.alreadyVisited( this.leftInput ) ) {
+ if ( needRemoveFromLeft ) {
this.leftInput.remove( context,
builder,
this,
workingMemories );
}
With this patch applied I could add/delete/add the particular rule
repeatedly without problems.
The attached patch also adds an assert in ObjectSource#removeObjectSink():
when removing a sink from an object source with
only one sink the sink was unconditionally replaced with an empty sink,
although the argument ObjectSink could be a different
sink than the one in the ObjectSource. For CompositeObjectSinkAdapters this
case is checked, but not for single sinks.
I originally suspected that place to be responsible for the problem I
observed but the assertion never fired in my tests.
Should I open a JIRA issue? Unfortunately I cannot provide a DRL to
reproduce the issue, but I could
try dumping the rulebase if that would help.
Regards,
--
Andreas
--
Never attribute to malice that which can be adequately explained by
stupidity. -- Hanlon's Razor
_______________________________________________
rules-dev mailing list
rules-dev(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-dev
--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com
3 a.m.
On Tue, 2010-03-30 at 13:00 -0400, Edson Tirelli wrote:
Hi Andreas,
Yes, please open a JIRA and attach your patch. I will try to
reproduce and create a test case from your description, but sometimes
it would be faster if you could provide a dumbed down or obfuscated
version of the rule you are using that is causing the problem...
I created https://jira.jboss.org/jira/browse/JBRULES-2465
We're currently in a release crunch, so I can't get you a self-contained
test right now, but I'll try to get around to it.
Thanks,
--
Andreas
Thanks,
Edson
2010/3/29 Andreas Kohn <andreas.kohn(a)fredhopper.com>
Hi,
while working further on our drools integration we came across
an odd
exception when removing a particular rule:
java.lang.IllegalArgumentException: Cannot remove a sink, when
the list of sinks is null
at
org.drools.reteoo.ObjectSource.removeObjectSink(ObjectSource.java:159)
at
org.drools.reteoo.RightInputAdapterNode.doRemove(RightInputAdapterNode.java:217)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at
org.drools.reteoo.BetaNode.doRemove(BetaNode.java:275)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at
org.drools.reteoo.BetaNode.doRemove(BetaNode.java:280)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at
org.drools.reteoo.RuleTerminalNode.doRemove(RuleTerminalNode.java:387)
at org.drools.common.BaseNode.remove(BaseNode.java:95)
at
org.drools.reteoo.ReteooBuilder.removeRule(ReteooBuilder.java:237)
at
org.drools.reteoo.ReteooRuleBase.removeRule(ReteooRuleBase.java:371)
at
org.drools.common.AbstractRuleBase.removeRule(AbstractRuleBase.java:746)
While stepping through the code it looked like the network was
corrupt (there was indeed no
sinks on the ObjectSource, but the node calling
removeObjectSink was still linked to it
and claiming it as source).
The rule itself contains multiple NotNodes, checking a
condition that looks like this:
not(not(Foo.v = X) and not(Foo.v = Y))
I could track this down to some sort of "loop" in the rete
that triggers this when the outer
not node is removed.
When removing BetaNode#doRemove() first walks along
'rightInput':
this.rightInput.remove( context,
builder,
this,
workingMemories );
and eventually _in that call_ it also hits a node that is the
direct 'leftInput' of the original beta node.
The removal marks that node as visited in the removal context,
and when the 'rightInput.remove' returns to the
beta node it does not visit the leftInput due to this
condition in BetaNode#doRemove():
if ( !context.alreadyVisited( this.leftInput ) ) {
this.leftInput.remove( context,
builder,
this,
workingMemories );
}
In other words: before the remove the BetaNode had another
node that was both referenced directly as 'leftInput',
as well as an input to the 'rightInput'.
The first removal of the rule "worked", and no exceptions
happened. But: any further attempt to re-add the same rule and
remove
it again lead to the exception above.
I was able to fix it with the attached patch, reproduced here:
+ boolean needRemoveFromLeft = !
context.alreadyVisited( this.leftInput );
this.rightInput.remove( context,
builder,
this,
workingMemories );
- if ( !context.alreadyVisited( this.leftInput ) ) {
+ if ( needRemoveFromLeft ) {
this.leftInput.remove( context,
builder,
this,
workingMemories );
}
With this patch applied I could add/delete/add the particular
rule repeatedly without problems.
The attached patch also adds an assert in
ObjectSource#removeObjectSink(): when removing a sink from an
object source with
only one sink the sink was unconditionally replaced with an
empty sink, although the argument ObjectSink could be a
different
sink than the one in the ObjectSource. For
CompositeObjectSinkAdapters this case is checked, but not for
single sinks.
I originally suspected that place to be responsible for the
problem I observed but the assertion never fired in my tests.
Should I open a JIRA issue? Unfortunately I cannot provide a
DRL to reproduce the issue, but I could
try dumping the rulebase if that would help.
Regards,
--
Andreas
--
Never attribute to malice that which can be adequately
explained by
stupidity. -- Hanlon's
Razor
_______________________________________________
rules-dev mailing list
rules-dev(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-dev
--
Edson Tirelli
JBoss Drools Core Development
JBoss by Red Hat @ www.jboss.com
_______________________________________________
rules-dev mailing list
rules-dev(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-dev
--
Never attribute to malice that which can be adequately explained by
stupidity. -- Hanlon's Razor
5385
days inactive
5387
days old
2 comments
2 participants
participants (2)
-
Andreas Kohn -
Edson Tirelli