To run this sample:
mvn clean installcd child-modulemvn package -Pnative
Java version from sdkman:
openjdk version "17.0.3" 2022-04-19
OpenJDK Runtime Environment GraalVM CE 22.1.0 (build 17.0.3+7-jvmci-22.1-b06)
OpenJDK 64-Bit Server VM GraalVM CE 22.1.0 (build 17.0.3+7-jvmci-22.1-b06, mixed mode, sharing)
---- Experiment with netty and slf4j-simple ------
Using just netty and slf4j-simple results in the following error:
Fatal error: com.oracle.graal.pointsto.util.AnalysisError$ParsingError: Error encountered while parsing io.grpc.netty.shaded.io.netty.channel.nio.AbstractNioChannel.<init>(io.grpc.netty.shaded.io.netty.channel.Channel, java.nio.channels.SelectableChannel, int)
Parsing context:
at io.grpc.netty.shaded.io.netty.channel.nio.AbstractNioChannel.<init>(AbstractNioChannel.java:80)
at io.grpc.netty.shaded.io.netty.channel.nio.AbstractNioMessageChannel.<init>(AbstractNioMessageChannel.java:42)
at com.oracle.graal.pointsto.util.AnalysisError.parsingError(AnalysisError.java:141)
at com.oracle.graal.pointsto.flow.MethodTypeFlow.createTypeFlow(MethodTypeFlow.java:315)
at com.oracle.graal.pointsto.flow.MethodTypeFlow.ensureTypeFlowCreated(MethodTypeFlow.java:286)
at com.oracle.graal.pointsto.flow.MethodTypeFlow.addContext(MethodTypeFlow.java:107)
at com.oracle.graal.pointsto.DefaultAnalysisPolicy$DefaultSpecialInvokeTypeFlow.onObservedUpdate(DefaultAnalysisPolicy.java:364)
at com.oracle.graal.pointsto.flow.TypeFlow.notifyObservers(TypeFlow.java:487)
at com.oracle.graal.pointsto.flow.TypeFlow.update(TypeFlow.java:556)
at com.oracle.graal.pointsto.PointsToAnalysis$2.run(PointsToAnalysis.java:598)
at com.oracle.graal.pointsto.util.CompletionExecutor.executeCommand(CompletionExecutor.java:195)
at com.oracle.graal.pointsto.util.CompletionExecutor.lambda$executeService$0(CompletionExecutor.java:179)
at java.base/java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1395)
at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:373)
at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1182)
at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1655)
at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1622)
at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:165)
Caused by: com.oracle.graal.pointsto.constraints.UnsupportedFeatureException: No instances of org.slf4j.impl.SimpleLogger are allowed in the image heap as this class should be initialized at image runtime. To see how this object got instantiated use --trace-object-instantiation=org.slf4j.impl.SimpleLogger.
at com.oracle.svm.hosted.classinitialization.ClassInitializationFeature.checkImageHeapInstance(ClassInitializationFeature.java:133)
at com.oracle.graal.pointsto.meta.AnalysisUniverse.replaceObject(AnalysisUniverse.java:575)
at com.oracle.svm.hosted.ameta.AnalysisConstantReflectionProvider.replaceObject(AnalysisConstantReflectionProvider.java:217)
at com.oracle.svm.hosted.ameta.AnalysisConstantReflectionProvider.interceptValue(AnalysisConstantReflectionProvider.java:188)
at com.oracle.svm.hosted.ameta.AnalysisConstantReflectionProvider.readValue(AnalysisConstantReflectionProvider.java:102)
Note The slf4j dependency requires some configurations to be compatible with netty. Specifically --initialize-at-build-time=org.slf4j.impl.SimpleLogger,org.slf4j.impl.StaticLoggerBinder,org.slf4j.LoggerFactory. However, adding these configurations results in a conflict with Slf4LoggerFactory:
No instances of io.grpc.netty.shaded.io.netty.util.internal.logging.Slf4JLoggerFactory are allowed in the image heap as this class should be initialized at image runtime. To see how this object got instantiated use --trace-object-instantiation=io.grpc.netty.shaded.io.netty.util.internal.logging.Slf4JLoggerFactory.
------ Experiment with --initialize-at-run-time=...Slf4JLoggerFactory being absent ----------
Using a SNAPSHOT version of gax-grpc which doesn't initialize Slf4jLoggerFactory and Log4JLogger at runtime (or just grpc-netty without any --initalize-at-run-time) results in a successful build with some additional slf4j configurations.
CONCLUSION: Initializing these logging classes at run-time is incompatible when slf4j is present on the classpath, hence, is not a good solution to the resolving the following warning: Warning: class initialization of class io.grpc.netty.shaded.io.netty.util.internal.logging.Slf4JLoggerFactory failed with exception java.lang.NoClassDefFoundError: Could not initialize class io.grpc.netty.shaded.io.netty.util.internal.logging.Slf4JLoggerFactory. This class will be initialized at run time because option --allow-incomplete-classpath is used for image building. Use the option --initialize-at-run-time=io.grpc.netty.shaded.io.netty.util.internal.logging.Slf4JLoggerFactory to explicitly request delayed initialization of this class.