Migrating tomcat 7

Author: LikeTheSalad

instrumentation/tomcat/tomcat-7.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/tomcat/v7_0/Tomcat7InstrumentationModule.java

@@ -11,12 +11,14 @@
 import com.google.auto.service.AutoService;
 import io.opentelemetry.javaagent.extension.instrumentation.InstrumentationModule;
 import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
+import io.opentelemetry.javaagent.extension.instrumentation.internal.ExperimentalInstrumentationModule;
 import io.opentelemetry.javaagent.instrumentation.tomcat.common.TomcatServerHandlerInstrumentation;
 import java.util.List;
 import net.bytebuddy.matcher.ElementMatcher;
 
 @AutoService(InstrumentationModule.class)
-public class Tomcat7InstrumentationModule extends InstrumentationModule {
+public class Tomcat7InstrumentationModule extends InstrumentationModule
+    implements ExperimentalInstrumentationModule {
 
   public Tomcat7InstrumentationModule() {
     super("tomcat", "tomcat-7.0");
@@ -39,4 +41,9 @@ public List<TypeInstrumentation> typeInstrumentations() {
             packageName + ".Tomcat7ServerHandlerAdvice",
             packageName + ".Tomcat7AttachResponseAdvice"));
   }
+
+  @Override
+  public boolean isIndyReady() {
+    return true;
+  }
 }

instrumentation/tomcat/tomcat-7.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/tomcat/v7_0/Tomcat7ServerHandlerAdvice.java

@@ -9,43 +9,61 @@
 
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.Scope;
-import io.opentelemetry.javaagent.bootstrap.Java8BytecodeBridge;
 import io.opentelemetry.javaagent.bootstrap.http.HttpServerResponseCustomizerHolder;
+import javax.annotation.Nullable;
 import net.bytebuddy.asm.Advice;
 import org.apache.coyote.Request;
 import org.apache.coyote.Response;
 
 @SuppressWarnings("unused")
 public class Tomcat7ServerHandlerAdvice {
 
-  @Advice.OnMethodEnter(suppress = Throwable.class)
-  public static void onEnter(
-      @Advice.Argument(0) Request request,
-      @Advice.Argument(1) Response response,
-      @Advice.Local("otelContext") Context context,
-      @Advice.Local("otelScope") Scope scope) {
+  public static class AdviceScope {
+    private final Context context;
+    private final Scope scope;
 
-    Context parentContext = Java8BytecodeBridge.currentContext();
-    if (!helper().shouldStart(parentContext, request)) {
-      return;
+    private AdviceScope(Context context, Scope scope) {
+      this.context = context;
+      this.scope = scope;
     }
 
-    context = helper().start(parentContext, request);
+    @Nullable
+    public static AdviceScope start(Request request, Response response) {
+      Context parentContext = Context.current();
+      if (!helper().shouldStart(parentContext, request)) {
+        return null;
+      }
+
+      Context context = helper().start(parentContext, request);
 
-    scope = context.makeCurrent();
+      Scope scope = context.makeCurrent();
+
+      HttpServerResponseCustomizerHolder.getCustomizer()
+          .customize(context, response, Tomcat7ResponseMutator.INSTANCE);
+
+      return new AdviceScope(context, scope);
+    }
 
-    HttpServerResponseCustomizerHolder.getCustomizer()
-        .customize(context, response, Tomcat7ResponseMutator.INSTANCE);
+    public void end(Request request, Response response, Throwable throwable) {
+      helper().end(request, response, throwable, context, scope);
+    }
+  }
+
+  @Nullable
+  @Advice.OnMethodEnter(suppress = Throwable.class)
+  public static AdviceScope onEnter(
+      @Advice.Argument(0) Request request, @Advice.Argument(1) Response response) {
+    return AdviceScope.start(request, response);
   }
 
   @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
   public static void stopSpan(
       @Advice.Argument(0) Request request,
       @Advice.Argument(1) Response response,
-      @Advice.Thrown Throwable throwable,
-      @Advice.Local("otelContext") Context context,
-      @Advice.Local("otelScope") Scope scope) {
-
-    helper().end(request, response, throwable, context, scope);
+      @Advice.Thrown @Nullable Throwable throwable,
+      @Advice.Enter AdviceScope adviceScope) {
+    if (adviceScope != null) {
+      adviceScope.end(request, response, throwable);
+    }
   }
 }