From c9ebbc1228735a060ebb35c0d6393cadbeb10250 Mon Sep 17 00:00:00 2001
From: Lauri Tulmin <ltulmin@splunk.com>
Date: Sun, 23 Oct 2022 12:56:17 +0300
Subject: [PATCH] restore comment

---
 .../rocketmqclient/v4_8/TracingConsumeMessageHookImpl.java    | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/instrumentation/rocketmq/rocketmq-client/rocketmq-client-4.8/library/src/main/java/io/opentelemetry/instrumentation/rocketmqclient/v4_8/TracingConsumeMessageHookImpl.java b/instrumentation/rocketmq/rocketmq-client/rocketmq-client-4.8/library/src/main/java/io/opentelemetry/instrumentation/rocketmqclient/v4_8/TracingConsumeMessageHookImpl.java
index a1e307019bc5..be6e328bdc37 100644
--- a/instrumentation/rocketmq/rocketmq-client/rocketmq-client-4.8/library/src/main/java/io/opentelemetry/instrumentation/rocketmqclient/v4_8/TracingConsumeMessageHookImpl.java
+++ b/instrumentation/rocketmq/rocketmq-client/rocketmq-client-4.8/library/src/main/java/io/opentelemetry/instrumentation/rocketmqclient/v4_8/TracingConsumeMessageHookImpl.java
@@ -34,6 +34,10 @@ public void consumeMessageBefore(ConsumeMessageContext context) {
     Context parentContext = Context.current();
     Context newContext = instrumenter.start(parentContext, context.getMsgList());
 
+    // it's safe to store the scope in the rocketMq message context, both before() and after()
+    // methods are always called from the same thread; see:
+    // - ConsumeMessageConcurrentlyService$ConsumeRequest#run()
+    // - ConsumeMessageOrderlyService$ConsumeRequest#run()
     if (newContext != parentContext) {
       contextAndScopeField.set(
           context, ContextAndScope.create(newContext, newContext.makeCurrent()));