I think Krasnigor, Scott L (N-AST) wrote:
> Not a problem. Is there a simple fix I can implement. I am trying to
> prototype a failover capability and I am dead in the water without the
> bsave/bload functionality working. I have the source code. I will be
> happy to figure out a temporary fix if you can just point me in the
> right direction. Thanks.
I am thinking of something like this (jess/Rete.java. around like 1800):
public void bsave(OutputStream os) throws IOException {
ObjectOutputStream oos = new ObjectOutputStream(os);
synchronized (getActivationSemaphore()) {
synchronized (getCompiler()) {
oos.writeObject(m_globalContext);
...
The order of the two nested locks is, of course, significant.
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> On Behalf Of friedman_hill ernest j
> Sent: Thursday, June 22, 2006 9:43 AM
> To: [email protected]
> Subject: Re: JESS: Help with error
>
> I think Krasnigor, Scott L (N-AST) wrote:
> > I am getting the following exception when trying to do a bsave. It is
> > occurring when the bsave method is executing oss.writeObject(m_rules).
>
> > I don't understand what could be causing this and am looking for any
> > insight into the issue. I am running Jess version 70b7 from a java
> > application. I will be happy to provide more detail if needed. Thanks.
>
> Looks like this is caused by new rules being activated during the call
> to "bsave," presumably because working memory is being modified on
> another thread. I'm surprised this has never come up before, because
> thinking of it, it seems that bsave() should probably lock the agenda
> and working memory while it runs -- but it does not. Thanks for
> reporting this.
>
>
>
> >
> > Jess reported an error in routine bsave
> > while executing (bsave enginedata).
> > Message: Error during execution.
> > Program text: ( bsave enginedata ) at line 1.
> > at jess.Funcall.execute(Funcall.java:328)
> > at jess.Jesp.parseAndExecuteFuncall(Jesp.java:2261)
> > at jess.Jesp.parseExpression(Jesp.java:436)
> > at jess.Jesp.promptAndParseOneExpression(Jesp.java:291)
> > at jess.Jesp.parse(Jesp.java:270)
> > at jess.Rete.eval(Rete.java:2051)
> > at jess.Rete.eval(Rete.java:2006)
> > at control.Controller.run(Controller.java:67)
> > at java.lang.Thread.run(Unknown Source) Caused by:
> > java.util.ConcurrentModificationException
> > at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
> > at java.util.HashMap$EntryIterator.next(Unknown Source)
> > at java.util.HashMap$EntryIterator.next(Unknown Source)
> > at java.util.HashMap.writeObject(Unknown Source)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
> > at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> > Source)
> > at java.lang.reflect.Method.invoke(Unknown Source)
> > at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
> > at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
> > at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown
> > Source)
> > at java.io.ObjectOutputStream.writeObject0(Unknown Source)
> > at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source)
> > at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
> > at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown
> > Source)
> > at java.io.ObjectOutputStream.writeObject0(Unknown Source)
> > at java.io.ObjectOutputStream.writeObject(Unknown Source)
> > at java.util.TreeMap.writeObject(Unknown Source)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
> > at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> > Source)
> > at java.lang.reflect.Method.invoke(Unknown Source)
> > at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
> > at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
> > at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown
> > Source)
> > at java.io.ObjectOutputStream.writeObject0(Unknown Source)
> > at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source)
> > at java.io.ObjectOutputStream.defaultWriteObject(Unknown Source)
> > at java.util.Collections$SynchronizedMap.writeObject(Unknown
> > Source)
> > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> > at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
> > at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown
> > Source)
> > at java.lang.reflect.Method.invoke(Unknown Source)
> > at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)
> > at java.io.ObjectOutputStream.writeSerialData(Unknown Source)
> > at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown
> > Source)
> > at java.io.ObjectOutputStream.writeObject0(Unknown Source)
> > at java.io.ObjectOutputStream.writeObject(Unknown Source)
> > at jess.Rete.bsave(Rete.java:1768)
> > at jess.Dumper.call(DumpFunctions.java:43)
> > at jess.FunctionHolder.call(FunctionHolder.java:31)
> > at jess.Funcall.execute(Funcall.java:320)
> > ... 8 more
> >
> > Scott L. Krasnigor
> > Principal Engineer/Scientist
> > Advanced Sciences & Technologies, LLC.
> > Lockheed Martin - MS2
> > ' 856-359-3094
> > * [EMAIL PROTECTED]
> > * 780-1A
> >
>
>
>
> ---------------------------------------------------------
> Ernest Friedman-Hill
> Advanced Software Research Phone: (925) 294-2154
> Sandia National Labs FAX: (925) 294-2234
> PO Box 969, MS 9012 [EMAIL PROTECTED]
> Livermore, CA 94550 http://herzberg.ca.sandia.gov
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>
---------------------------------------------------------
Ernest Friedman-Hill
Advanced Software Research Phone: (925) 294-2154
Sandia National Labs FAX: (925) 294-2234
PO Box 969, MS 9012 [EMAIL PROTECTED]
Livermore, CA 94550 http://herzberg.ca.sandia.gov
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