MetaMember not found for X

[aryairani]

I am getting hundreds of errors like
MetaMember not found for org.mypkg.benchmark.Compilation2Benchmarks$ fib$1,
corresponding to the classes that I specifically want to analyze. 😄
I believe I've set the sources and classes correctly in config. The class and method do exist:

$ javap -p org.mypkg.benchmark.Compilation2Benchmarks$ | grep fib$1
  private static final int fib$1(int);

Where should I go from here?

[aryairani]

A weirder one:

Could not parse line 1148 : org.u.Lib2$$$Lambda$30.1002191352 apply (DD)D : 
MetaMember not found for org.u.Lib2$$$Lambda$30.1002191352 apply (DD)D

the corresponding line is

<task_queued compile_id='500' method='org.u.Lib2$$$Lambda$30/1002191352 apply (DD)D'
  bytes='6' count='3968' iicount='3968' level='3' stamp='1.236' comment='tiered' hot_count='3968'/>

and I'm not sure how to interpret that one at all. I do have an org.u.Lib2$.class$ but nothing with both Lib2andLambda` in the class file name.

[chriswhocodes]

Hi,

For the first one, if you've set up the config then that could be a bug. Is there any more detail in a file called jitwatch.out in your jitwatch directory?

For the second one, those look like autogenerated classes if you are using functional programming in JDK8+ (lambdas) but this could be related to the first problem.

Thanks,

Chris

[aryairani]

Thanks Chris. Will JDK8 lambdas be problematic? I am using them.

[chriswhocodes]

Hi, I've not tested much (any?) lambda code in JITWatch yet. Do you have a short example program you could share and I'll see if I can get JITWatch to analyse it correctly?

Thanks

[stevenschlansker]

I similarly was attempting to use jitwatch specifically to dive into the performance of lambdas (and LambdaMetafactory) but also ran into this limitation:

Could not parse line 169708 : com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$71.0x00000008400f9c40 get ()Ljava.lang.Object; : MetaMember not found for com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$71.0x00000008400f9c40 get ()Ljava.lang.Object;
Could not parse line 169711 : com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$54.0x00000008400dc040 accept (Ljava.lang.Object;Ljava.lang.Object;)V : MetaMember not found for com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$54.0x00000008400dc040 accept (Ljava.lang.Object;Ljava.lang.Object;)V
Could not parse line 170960 : com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$51.0x00000008400dd040 accept (Ljava.lang.Object;I)V : MetaMember not found for com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$51.0x00000008400dd040 accept (Ljava.lang.Object;I)V
Could not parse line 170961 : com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$52.0x00000008400dd440 accept (Ljava.lang.Object;Ljava.lang.Object;)V : MetaMember not found for com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$52.0x00000008400dd440 accept (Ljava.lang.Object;Ljava.lang.Object;)V
Could not parse line 172129 : com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$54.0x00000008400dc040 accept (Ljava.lang.Object;Ljava.lang.Object;)V : MetaMember not found for com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$54.0x00000008400dc040 accept (Ljava.lang.Object;Ljava.lang.Object;)V
Could not parse line 173207 : com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$55.0x00000008400dc440 accept (Ljava.lang.Object;Ljava.lang.Object;)V : MetaMember not found for com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$55.0x00000008400dc440 accept (Ljava.lang.Object;Ljava.lang.Object;)V
Could not parse line 218766 : com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$55.0x00000008400dc440 accept (Ljava.lang.Object;Ljava.lang.Object;)V : MetaMember not found for com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$55.0x00000008400dc440 accept (Ljava.lang.Object;Ljava.lang.Object;)V
Could not parse line 219447 : com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$51.0x00000008400dd040 accept (Ljava.lang.Object;I)V : MetaMember not found for com.fasterxml.jackson.module.blackbird.BaseBenchmark$SomeBean$$Lambda$51.0x00000008400dd040 accept (Ljava.lang.Object;I)V
Could not parse line 227589 : java.util.regex.Pattern$$Lambda$6.0x0000000840066040 is (I)Z : MetaMember not found for java.util.regex.Pattern$$Lambda$6.0x0000000840066040 is (I)Z
Could not parse line 227592 : java.util.regex.Pattern$$Lambda$6.0x0000000840066040 is (I)Z : MetaMember not found for java.util.regex.Pattern$$Lambda$6.0x0000000840066040 is (I)Z
Could not parse line 237526 : java.util.regex.CharPredicates$$Lambda$31.0x000000084007a440 is (I)Z : MetaMember not found for java.util.regex.CharPredicates$$Lambda$31.0x000000084007a440 is (I)Z
Could not parse line 238304 : java.util.regex.CharPredicates$$Lambda$31.0x000000084007a440 is (I)Z : MetaMember not found for java.util.regex.CharPredicates$$Lambda$31.0x000000084007a440 is (I)Z
Could not parse line 240373 : java.util.regex.Pattern$$Lambda$33.0x000000084007ac40 is (I)Z : MetaMember not found for java.util.regex.Pattern$$Lambda$33.0x000000084007ac40 is (I)Z
Could not parse line 240376 : java.util.regex.Pattern$$Lambda$33.0x000000084007ac40 is (I)Z : MetaMember not found for java.util.regex.Pattern$$Lambda$33.0x000000084007ac40 is (I)Z
Could not parse line 240762 : java.util.regex.Pattern$BmpCharPredicate$$Lambda$35.0x000000084007b440 is (I)Z : MetaMember not found for java.util.regex.Pattern$BmpCharPredicate$$Lambda$35.0x000000084007b440 is (I)Z
Could not parse line 240767 : java.util.regex.Pattern$BmpCharPredicate$$Lambda$35.0x000000084007b440 is (I)Z : MetaMember not found for java.util.regex.Pattern$BmpCharPredicate$$Lambda$35.0x000000084007b440 is (I)Z
Could not parse line 254447 : java.util.regex.Pattern$$Lambda$34.0x000000084007b040 is (I)Z : MetaMember not found for java.util.regex.Pattern$$Lambda$34.0x000000084007b040 is (I)Z
Could not parse line 254451 : java.util.regex.Pattern$$Lambda$34.0x000000084007b040 is (I)Z : MetaMember not found for java.util.regex.Pattern$$Lambda$34.0x000000084007b040 is (I)Z

It is not trivial, but I am running:
https://github.com/stevenschlansker/jackson-blackbird
as
java -XX:+UnlockDiagnosticVMOptions -XX:+LogCompilation -XX:+PrintAssembly -XX:+TraceClassLoading -jar benchmarks/target/benchmarks.jar -f 0 -wi 50 -i 50 Blackbird.beanDeser

Hoping that jitwatch can understand lambdas soon, this feature will not be going away :)

[chriswhocodes]

Hi @stevenschlansker thanks for providing a reproducer for this issue.
A lot of JITWatch functionality relies on the bytecode for a method being available (this was one of the design assumptions) but I don't think this is available after the program exits in the case of lambdas so I need to find a way to build the class model as best I can from method signatures found in the logs etc.
Will give it some thought.
Kind regards,
Chris

[JohnTortugo]

@chriswhocodes - is there any plan for supporting this?

[YujiSoftware]

@chriswhocodes

A lot of JITWatch functionality relies on the bytecode for a method being available (this was one of the design assumptions) but I don't think this is available after the program exits in the case of lambdas so I need to find a way to build the class model as best I can from method signatures found in the logs etc.

Anonymous classes for lambdas can be exported to the path specified by the system property "jdk.internal.lambda.dumpProxyClasses"

Example: java -Djdk.internal.lambda.dumpProxyClasses=. Main.java
https://github.com/openjdk/jdk/blob/c6339cb8a255d387bb182ad20dd69f3d460cf1ed/src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java#L100-L102

Maybe, you can get the method signature.

[chriswhocodes]

Hi, I'm closing all the issues except for the ones I'm actively working on.

[alexei-osipov]

Maybe it's worth to add to JITWatch description or documentation info that lambdas are not supported and there are no plans to support them?