CompileException invalid stack height 2 expecting 1

[whitingjr]

Hi,

I am getting this exception when a Byteman Rule is being initially loaded on my server.

19:58:18,028 INFO  [stdout] (ServerService Thread Pool -- 60) Rule.ensureTypeCheckedCompiled : error compiling rule TxConnectionListener state

19:58:18,028 INFO  [stdout] (ServerService Thread Pool -- 60) org.jboss.byteman.rule.exception.CompileException: FieldExpression.compile : invalid stack height 2 expecting 1

19:58:18,028 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.expression.FieldExpression.compile(FieldExpression.java:298)

19:58:18,028 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.expression.LogicalExpression.compile(LogicalExpression.java:104)

19:58:18,029 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.Condition.compile(Condition.java:101)

19:58:18,029 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.compiler.Compiler.compileBytes(Compiler.java:406)

19:58:18,029 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.compiler.Compiler.getHelperAdapter(Compiler.java:64)

19:58:18,029 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.Rule.compile(Rule.java:545)

19:58:18,029 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.Rule.ensureTypeCheckedCompiled(Rule.java:450)

19:58:18,029 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.Rule.execute(Rule.java:672)

19:58:18,029 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.byteman.rule.Rule.execute(Rule.java:653)

19:58:18,029 INFO  [stdout] (ServerService Thread Pool -- 60)   at org.jboss.jca.core.connectionmanager.listener.TxConnectionListener.setTrackByTx(TxConnectionListener.java)

1

Using the bmcheck tool no errors or warnings were reported.

$ bmcheck -cp ./java/jboss/ironjacamar/ironjacamar_1.0.21/target/ironjacamar-core-impl.jar -cp ./java/jboss/ironjacamar/ironjacamar_1.0.21/target/ironjacamar-core-api.jar -cp ./java/jboss/jboss-eap-6.2.0.ER7/modules/system/layers/base/javax/resource/api/main/jboss-connector-api_1.6_spec-1.0.1.Final-redhat-2.jar -cp ./java/jboss/jboss-eap-6.2.0.ER7/modules/system/layers/base/javax/transaction/api/main/jboss-transaction-api_1.1_spec-1.0.1.Final-redhat-2.jar -cp ./java/jboss/jboss-eap-6.2.0.ER7/modules/system/layers/base/org/jboss/logging/main/jboss-logging-3.1.2.GA-redhat-1.jar ./java/jboss/byteman/byteman-download-2.1.3/sample/scripts/ConnectionTrackByTxStateMonitor.btm

checking rule TxConnectionListener state against class org.jboss.jca.core.connectionmanager.listener.TxConnectionListener

parsed rule "TxConnectionListener state" for class org.jboss.jca.core.connectionmanager.listener.TxConnectionListener

type checked rule "TxConnectionListener state"

TestScript: no errors

This is my Byteman script

# StateMonitor

#

# A byteman script which finds a condition causing the state for connection

# tracking to change during a transaction.

#

########################################################################

#

# Rule to detect state change

#

RULE TxConnectionListener state

CLASS org.jboss.jca.core.connectionmanager.listener.TxConnectionListener

METHOD setTrackByTx(boolean)

AT ENTRY

IF (!$1)

   AND

   ($this.isTrackByTx())

   AND

   ($this.getTransactionSynchronization().enlisted)

DO traceStack("*** the trackByTx state is being changed to false for an inflight transaction by thread name ["+Thread.currentThread().getName()+ "]. ***")

ENDRULE

The class the rule has been written for is added as an attachment.

[adinn]

Hi Jeremy,

Jeremy Whiting wrote:

Hi,

I am getting this exception when a Byteman Rule is being initially loaded on my server.

. . .

Thanks very much for the fully detailed error report. That should make it very easy to find the problem.

What I can see straight away is that the error is happening during the runtime type check of  the rule but only because the rule is being compiled to bytecode. The offline type checker does not normally compile rules when it performs its type checking so that explains the disparity between testing and offline checking. If you set

BYTEMAN_JAVA_OPTS="-Dorg.jboss.byteman.compile.to.bytecode"

when you run bmcheck.sh (yes, the value of the that environment variable gets added to the java command line :-)  I would expect you to see the error during the offline type check.

When the Byteman engine compiles to bytecode it walks the expression tree of the parsed rule and generates bytecode to implement the desired behaviours. As a sanity check it tracks the stack heights before and after translating an expression and ensures that they differ by teh expected amount. Clearly, something is going  wrong when translating the field access in your condition, either in the counted heights or in the expectations. I'll check this as soon as I can and try to include a fix in the next Byteman release.

[adinn]

And here is the JIRA BYTEMAN-253

[whitingjr]

Thanks for creating a jira.

[whitingjr]

Thank you for the detailed explanation.

So to get round this I removed the option "-Dorg.jboss.byteman.compile.to.bytecode" on the server. Transformation when the code is initially executed is working fine.

Many thanks.