Remove AgentTracer.noopScope() sentinel from advice call sites (#12010)

Remove AgentTracer.noopScope() sentinel from advice call sites

Replace noopScope() with null where the returned scope has no observable side effects to preserve.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Co-authored-by: devflow.devflow-routing-intake <devflow.devflow-routing-intake@kubernetes.us1.ddbuild.io>

Author: mcculls

dd-java-agent/instrumentation/netty/netty-4.0/src/main/java/datadog/trace/instrumentation/netty40/NettyChannelHandlerContextInstrumentation.java

@@ -5,7 +5,6 @@
 import static datadog.trace.agent.tooling.bytebuddy.matcher.NameMatchers.named;
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activateSpan;
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activeSpan;
-import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.noopScope;
 import static datadog.trace.bootstrap.instrumentation.api.Java8BytecodeBridge.spanFromContext;
 import static datadog.trace.instrumentation.netty40.AttributeKeys.CONTEXT_ATTRIBUTE_KEY;
 import static datadog.trace.instrumentation.netty40.NettyChannelPipelineInstrumentation.ADDITIONAL_INSTRUMENTATION_NAMES;
@@ -75,14 +74,16 @@ public static AgentScope scopeSpan(@Advice.This final ChannelHandlerContext ctx)
       final AgentSpan channelSpan = spanFromContext(storedContext);
       if (channelSpan == null || channelSpan == activeSpan()) {
         // don't modify the scope
-        return noopScope();
+        return null;
       }
       return activateSpan(channelSpan);
     }
 
     @Advice.OnMethodExit(suppress = Throwable.class, onThrowable = Throwable.class)
     public static void close(@Advice.Enter final AgentScope scope) {
-      scope.close();
+      if (scope != null) {
+        scope.close();
+      }
     }
 
     private void muzzleCheck() {

dd-java-agent/instrumentation/netty/netty-4.1/src/main/java/datadog/trace/instrumentation/netty41/NettyChannelHandlerContextInstrumentation.java

@@ -5,7 +5,6 @@
 import static datadog.trace.agent.tooling.bytebuddy.matcher.NameMatchers.named;
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activateSpan;
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activeSpan;
-import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.noopScope;
 import static datadog.trace.bootstrap.instrumentation.api.Java8BytecodeBridge.spanFromContext;
 import static datadog.trace.instrumentation.netty41.AttributeKeys.CONTEXT_ATTRIBUTE_KEY;
 import static datadog.trace.instrumentation.netty41.NettyChannelPipelineInstrumentation.ADDITIONAL_INSTRUMENTATION_NAMES;
@@ -75,14 +74,16 @@ public static AgentScope scopeSpan(@Advice.This final ChannelHandlerContext ctx)
       final AgentSpan channelSpan = spanFromContext(storedContext);
       if (channelSpan == null || channelSpan == activeSpan()) {
         // don't modify the scope
-        return noopScope();
+        return null;
       }
       return activateSpan(channelSpan);
     }
 
     @Advice.OnMethodExit(suppress = Throwable.class, onThrowable = Throwable.class)
     public static void close(@Advice.Enter final AgentScope scope) {
-      scope.close();
+      if (scope != null) {
+        scope.close();
+      }
     }
 
     private void muzzleCheck() {

dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-3.4/src/main/java/datadog/trace/instrumentation/vertx_3_4/server/RouteHandlerWrapper.java

@@ -2,7 +2,6 @@
 
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activateSpan;
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activeSpan;
-import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.noopScope;
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.startSpan;
 import static datadog.trace.bootstrap.instrumentation.decorator.http.HttpResourceDecorator.HTTP_RESOURCE_DECORATOR;
 import static datadog.trace.instrumentation.vertx_3_4.server.VertxDecorator.DECORATE;
@@ -62,7 +61,7 @@ public void handle(final RoutingContext routingContext) {
       }
       setRoute(routingContext);
     }
-    try (final ContextScope scope = span != null ? activateSpan(span) : noopScope()) {
+    try (final ContextScope scope = span != null ? activateSpan(span) : null) {
       try {
         actual.handle(routingContext);
       } catch (final Throwable t) {

dd-java-agent/instrumentation/vertx/vertx-web/vertx-web-4.0/src/main/java/datadog/trace/instrumentation/vertx_4_0/server/RouteHandlerWrapper.java

@@ -2,7 +2,6 @@
 
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activateSpan;
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.activeSpan;
-import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.noopScope;
 import static datadog.trace.bootstrap.instrumentation.api.AgentTracer.startSpan;
 import static datadog.trace.bootstrap.instrumentation.decorator.http.HttpResourceDecorator.HTTP_RESOURCE_DECORATOR;
 import static datadog.trace.instrumentation.vertx_4_0.server.VertxDecorator.DECORATE;
@@ -61,7 +60,7 @@ public void handle(final RoutingContext routingContext) {
       setRoute(routingContext);
     }
 
-    try (final ContextScope scope = span != null ? activateSpan(span) : noopScope()) {
+    try (final ContextScope scope = span != null ? activateSpan(span) : null) {
       try {
         actual.handle(routingContext);
       } catch (final Throwable t) {

internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentTracer.java

@@ -670,7 +670,7 @@ public Context currentContext() {
 
     @Override
     public ContextScope attach(Context context) {
-      return noopScope();
+      return NoopScope.INSTANCE;
     }
 
     @Override