Keep tracingMode on TraceRecordingState (#53077)

Summary:
Pull Request resolved: #53077

# Changelog: [Internal]

Stores the tracing::Mode on a TraceRecordingState and updates the logic for:
- InstanceTracingAgent to enable PerformanceTracer with a specified window size
- RuntimeTracingAgent to only enable sampling profiler for CDP-initiated sessions

Reviewed By: sbuggay

Differential Revision: D79670864

fbshipit-source-id: 2c4eacb29666b59acbc508848a0a3d859f21a403

Author: hoxyq

packages/react-native/ReactCommon/jsinspector-modern/HostTargetTraceRecording.cpp

@@ -29,7 +29,10 @@ void HostTargetTraceRecording::start() {
       hostTracingAgent_ == nullptr &&
       "Tracing Agent for the HostTarget was already initialized.");
 
-  state_ = tracing::TraceRecordingState{.startTime = HighResTimeStamp::now()};
+  state_ = tracing::TraceRecordingState{
+      .mode = tracingMode_,
+      .startTime = HighResTimeStamp::now(),
+  };
   hostTracingAgent_ = hostTarget_.createTracingAgent(*state_);
 }
 

packages/react-native/ReactCommon/jsinspector-modern/InstanceAgent.cpp

@@ -15,6 +15,15 @@
 
 namespace facebook::react::jsinspector_modern {
 
+namespace {
+
+// The size of the timeline for the trace recording that happened in the
+// background.
+constexpr HighResDuration kBackgroundTracePerformanceTracerWindowSize =
+    HighResDuration::fromMilliseconds(20000);
+
+} // namespace
+
 InstanceAgent::InstanceAgent(
     FrontendChannel frontendChannel,
     InstanceTarget& target,
@@ -160,7 +169,12 @@ void InstanceAgent::maybeSendPendingConsoleMessages() {
 
 InstanceTracingAgent::InstanceTracingAgent(tracing::TraceRecordingState& state)
     : tracing::TargetTracingAgent(state) {
-  tracing::PerformanceTracer::getInstance().startTracing();
+  auto& performanceTracer = tracing::PerformanceTracer::getInstance();
+  if (state.mode == tracing::Mode::Background) {
+    performanceTracer.startTracing(kBackgroundTracePerformanceTracerWindowSize);
+  } else {
+    performanceTracer.startTracing();
+  }
 }
 
 InstanceTracingAgent::~InstanceTracingAgent() {

packages/react-native/ReactCommon/jsinspector-modern/RuntimeAgent.cpp

@@ -134,14 +134,18 @@ RuntimeTracingAgent::RuntimeTracingAgent(
     tracing::TraceRecordingState& state,
     RuntimeTargetController& targetController)
     : tracing::TargetTracingAgent(state), targetController_(targetController) {
-  targetController_.enableSamplingProfiler();
+  if (state.mode == tracing::Mode::CDP) {
+    targetController_.enableSamplingProfiler();
+  }
 }
 
 RuntimeTracingAgent::~RuntimeTracingAgent() {
-  targetController_.disableSamplingProfiler();
-  auto profile = targetController_.collectSamplingProfile();
+  if (state_.mode == tracing::Mode::CDP) {
+    targetController_.disableSamplingProfiler();
+    auto profile = targetController_.collectSamplingProfile();
 
-  state_.runtimeSamplingProfiles.emplace_back(std::move(profile));
+    state_.runtimeSamplingProfiles.emplace_back(std::move(profile));
+  }
 }
 
 } // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/tracing/TraceRecordingState.h

@@ -9,6 +9,7 @@
 
 #include "InstanceTracingProfile.h"
 #include "RuntimeSamplingProfile.h"
+#include "TracingMode.h"
 
 #include <oscompat/OSCompat.h>
 #include <react/timing/primitives.h>
@@ -18,6 +19,9 @@
 namespace facebook::react::jsinspector_modern::tracing {
 
 struct TraceRecordingState {
+  // The mode of this Trace Recording.
+  tracing::Mode mode;
+
   // The ID of the OS-level process that this Trace Recording is associated
   // with.
   ProcessId processId = oscompat::getCurrentProcessId();