Fix context propagation for guava AsyncEventBus (open-telemetry#14791)

Co-authored-by: otelbot <[email protected]>
Co-authored-by: Lauri Tulmin <[email protected]>

Author: 3 people

instrumentation/guava-10.0/javaagent/src/test/java/io/opentelemetry/javaagent/instrumentation/guava/v10_0/AsyncEventBusTest.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.instrumentation.guava.v10_0;
+
+import com.google.common.eventbus.AsyncEventBus;
+import com.google.common.eventbus.Subscribe;
+import io.opentelemetry.instrumentation.testing.junit.AgentInstrumentationExtension;
+import io.opentelemetry.instrumentation.testing.junit.InstrumentationExtension;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+class AsyncEventBusTest {
+
+  @RegisterExtension
+  static final InstrumentationExtension testing = AgentInstrumentationExtension.create();
+
+  static final ExecutorService executor = Executors.newSingleThreadExecutor();
+  static final AsyncEventBus asyncEventBus = new AsyncEventBus(executor);
+
+  @Test
+  void contextPropagation() {
+    class Listener {
+
+      @Subscribe
+      public void onEvent(String event) {
+        testing.runWithSpan("listener", () -> {});
+      }
+    }
+
+    asyncEventBus.register(new Listener());
+
+    testing.runWithSpan("parent", () -> asyncEventBus.post("test"));
+
+    testing.waitAndAssertTraces(
+        trace ->
+            trace.hasSpansSatisfyingExactly(
+                span -> span.hasName("parent"), span -> span.hasName("listener")));
+  }
+}

javaagent-tooling/src/main/java/io/opentelemetry/javaagent/tooling/ignore/AdditionalLibraryIgnoredTypesConfigurer.java

@@ -250,7 +250,8 @@ public void configure(IgnoredTypesBuilder builder) {
         .ignoreClass("com.google.common.")
         .allowClass("com.google.common.util.concurrent.")
         .allowClass("com.google.common.base.internal.Finalizer")
-        .allowClass("com.google.common.base.Java8Usage$$Lambda");
+        .allowClass("com.google.common.base.Java8Usage$$Lambda")
+        .allowClass("com.google.common.eventbus.Subscriber$");
 
     builder
         .ignoreClass("com.google.inject.")