Fix redefinition failure on openj9

instrumentation/internal/internal-reflection/bootstrap/build.gradle.kts

@@ -0,0 +1,3 @@
+plugins {
+ id("otel.javaagent-bootstrap")
+}

instrumentation/internal/internal-reflection/bootstrap/src/main/java/io/opentelemetry/javaagent/instrumentation/internal/reflection/RealInterfaces.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.instrumentation.internal.reflection;
+
+import java.util.Collections;
+import java.util.Map;
+import java.util.WeakHashMap;
+
+public final class RealInterfaces {
+ private static final Map<Class<?>, Class<?>[]> realInterfaces =
+ Collections.synchronizedMap(new WeakHashMap<>());
+
+ private RealInterfaces() {}
+
+ /**
+ * Returns the interfaces directly implemented by the given class or interface. We instrument
+ * Class#getInterfaces() to remove interfaces added by us. This method can be used to get the
+ * interfaces that the class directly implements including the interfaces that we have added.
+ *
+ * @param clazz class or interface
+ * @return interfaces directly implemented by given class
+ */
+ public static Class<?>[] get(Class<?> clazz) {
+ // instrumentation calls RealInterfaces#set() from Class#getInterfaces()
+ Class<?>[] interfaces = clazz.getInterfaces();
+ Class<?>[] real = realInterfaces.get(clazz);
+ return real != null ? real : interfaces;
+ }
+
+ static void set(Class<?> clazz, Class<?>[] interfaces) {
+ realInterfaces.put(clazz, interfaces);
+ }
+}

instrumentation/internal/internal-reflection/javaagent/build.gradle.kts

@@ -3,6 +3,8 @@ plugins {
 }
 
 dependencies {
+ bootstrap(project(":instrumentation:internal:internal-reflection:bootstrap"))
+
  compileOnly(project(":javaagent-bootstrap"))
 
  testImplementation(project(":javaagent-bootstrap"))

instrumentation/internal/internal-reflection/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/internal/reflection/ReflectionHelper.java

@@ -70,6 +70,10 @@ public static Class<?>[] filterInterfaces(Class<?>[] interfaces, Class<?> contai
  }
  result.add(interfaceClass);
  }
+ if (result.size() != interfaces.length) {
+ // for classes that have removed interfaces remember what they really have
+ RealInterfaces.set(containingClass, interfaces);
+ }
  return result.toArray(new Class<?>[0]);
  }
 }

javaagent-tooling/build.gradle.kts

@@ -18,6 +18,7 @@ dependencies {
  implementation(project(":instrumentation-api-appender"))
  implementation(project(":instrumentation-sdk-appender"))
  implementation(project(":muzzle"))
+ implementation(project(":instrumentation:internal:internal-reflection:bootstrap"))
 
  implementation("io.opentelemetry:opentelemetry-api")
  implementation("io.opentelemetry:opentelemetry-api-metrics")

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/field/FieldBackedImplementationInstaller.java

@@ -13,6 +13,7 @@
 import io.opentelemetry.instrumentation.api.config.Config;
 import io.opentelemetry.javaagent.bootstrap.InstrumentationHolder;
 import io.opentelemetry.javaagent.bootstrap.VirtualFieldInstalledMarker;
+import io.opentelemetry.javaagent.instrumentation.internal.reflection.RealInterfaces;
 import io.opentelemetry.javaagent.tooling.HelperInjector;
 import io.opentelemetry.javaagent.tooling.TransformSafeLogger;
 import io.opentelemetry.javaagent.tooling.instrumentation.InstrumentationModuleInstaller;
@@ -216,13 +217,12 @@ private static AgentBuilder.RawMatcher safeToInjectFieldsMatcher() {
  /*
  * The idea here is that we can add fields if class is just being loaded
  * (classBeingRedefined == null) and we have to add same fields again if class we added
- * fields before is being transformed again. Note: here we assume that Class#getInterfaces()
- * returns list of interfaces defined immediately on a given class, not inherited from its
- * parents. It looks like current JVM implementation does exactly this but javadoc is not
- * explicit about that.
+ * fields before is being transformed again. As we instrument Class#getInterfaces() to remove
+ * interfaces added by us, we need to use our own helper class to get all the interfaces that
+ * the class directly implements.
  */
  return classBeingRedefined == null
- || Arrays.asList(classBeingRedefined.getInterfaces())
+ || Arrays.asList(RealInterfaces.get(classBeingRedefined))
  .contains(VirtualFieldInstalledMarker.class);
  };
  }

settings.gradle.kts

@@ -153,6 +153,7 @@ include(":instrumentation:internal:internal-class-loader:javaagent-integration-t
 include(":instrumentation:internal:internal-eclipse-osgi-3.6:javaagent")
 include(":instrumentation:internal:internal-lambda:javaagent")
 include(":instrumentation:internal:internal-lambda-java9:javaagent")
+include(":instrumentation:internal:internal-reflection:bootstrap")
 include(":instrumentation:internal:internal-reflection:javaagent")
 include(":instrumentation:internal:internal-reflection:javaagent-integration-tests")
 include(":instrumentation:internal:internal-url-class-loader:javaagent")