From a2a73739d80c6a1d120e16246614ed4894de7b8a Mon Sep 17 00:00:00 2001
From: Ruslan Lesiutin <hoxy@meta.com>
Date: Thu, 21 Aug 2025 14:18:27 -0700
Subject: [PATCH] fix: use ThreadId when event is captured, not when
 transformed (#53411)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/53411

# Changelog: [Internal]

This regressed after D80263154, when we introduced a local struct for PerforamanceTracerEvent.

We should use id of the thread where event was captured (registered), not where the transform to TraceEvent happened.

This makes sure that events like Event Loop tick or Microtasks phase tick are correctly point to JavaScript thread, not the thread where the transform could've taken place.

Reviewed By: sbuggay

Differential Revision: D80728931

fbshipit-source-id: d3af16e68adece9ebc37368fec2b8a17c1293b4b
---
 .../tracing/PerformanceTracer.cpp                   | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/packages/react-native/ReactCommon/jsinspector-modern/tracing/PerformanceTracer.cpp b/packages/react-native/ReactCommon/jsinspector-modern/tracing/PerformanceTracer.cpp
index 4c8e8cf7e5e..238003fd393 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/tracing/PerformanceTracer.cpp
+++ b/packages/react-native/ReactCommon/jsinspector-modern/tracing/PerformanceTracer.cpp
@@ -190,6 +190,7 @@ void PerformanceTracer::reportTimeStamp(
       .trackName = std::move(trackName),
       .trackGroup = std::move(trackGroup),
       .color = std::move(color),
+      .threadId = getCurrentThreadId(),
   });
 }
 
@@ -399,7 +400,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'X',
                 .ts = event.start,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .dur = event.end - event.start,
             });
           },
@@ -410,7 +411,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'X',
                 .ts = event.start,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .dur = event.end - event.start,
             });
           },
@@ -429,7 +430,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'I',
                 .ts = event.start,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .args = std::move(eventArgs),
             });
           },
@@ -449,7 +450,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'b',
                 .ts = event.start,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .args = std::move(beginEventArgs),
             });
             events.emplace_back(TraceEvent{
@@ -459,7 +460,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'e',
                 .ts = event.start + event.duration,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
             });
           },
           [&](PerformanceTracerEventTimeStamp&& event) {
@@ -500,7 +501,7 @@ void PerformanceTracer::enqueueTraceEventsFromPerformanceTracerEvent(
                 .ph = 'I',
                 .ts = event.createdAt,
                 .pid = processId_,
-                .tid = getCurrentThreadId(),
+                .tid = event.threadId,
                 .args = folly::dynamic::object("data", std::move(data)),
             });
           },