Scaffold support for Tracing by jsinspector (facebook#48836)

Summary:

# Changelog: [Internal]

When `Tracing.start` CDP method is received, here is what happens next:
- `TracingAgent`, which intercepts the event will propagate this status to `Instance` by calling `startTracing()` on `InstanceAgent`.
- `InstanceAgent` will propagate it to `Runtime` entities. The only difference, there is no concept of tracing for Runtime, it will only have an API for starting sampling profiler.

When `Tracing.end` CDP method is received, it is propagated in the same order.

There is also `collect*()` methods for collecting profiles.

This has multiple benefits:
- We can control when `Runtime` or `Instance` are recreated and can ask them to start recording trace profiles right away. This may be required when we would add support for Reload and Profile from Performance panel.
- We might leverage this setup in the future, once we add instrumentation for Network panel. `InstanceAgent` will get notified when tracing started and will correspondingly notify other part of the infrastructure that will be responsible for recording network calls.
- We remain being fully agnostic to the actual `Runtime`, see corresponding `RuntimeTargetDelegate` for `V8`. We don't have the capacity for implementing and maintaining sampling profiler capabilities for it, but this approach unblocks it from technical perspective, if someone would want to invest into this.

`InstanceProfile` is a superset of `RuntimeSamplingProfile`. In the future, `InstanceProfile` may also include things like `NetworkProfile`, or similar stuff.

The definition for `RuntimeSamplingProfile` will be added in D68414421 and relies on the availability of new API for sampling profiler in Hermes.

Differential Revision: D68327630

packages/react-native/ReactCommon/hermes/inspector-modern/chrome/HermesRuntimeTargetDelegate.cpp

@@ -28,6 +28,12 @@ using namespace facebook::hermes;
 namespace facebook::react::jsinspector_modern {
 
 #ifdef HERMES_ENABLE_DEBUGGER
+namespace {
+
+const uint16_t HERMES_SAMPLING_FREQUENCY_HZ = 1000;
+
+}
+
 class HermesRuntimeTargetDelegate::Impl final : public RuntimeTargetDelegate {
   using HermesStackTrace = debugger::StackTrace;
 
@@ -167,6 +173,18 @@ class HermesRuntimeTargetDelegate::Impl final : public RuntimeTargetDelegate {
         runtime_->getDebugger().captureStackTrace());
   }
 
+  void enableSamplingProfiler() override {
+    runtime_->enableSamplingProfiler(HERMES_SAMPLING_FREQUENCY_HZ);
+  }
+
+  void disableSamplingProfiler() override {
+    runtime_->disableSamplingProfiler();
+  }
+
+  tracing::RuntimeSamplingProfile collectSamplingProfile() override {
+    return tracing::RuntimeSamplingProfile{};
+  }
+
  private:
   HermesRuntimeTargetDelegate& delegate_;
   std::shared_ptr<HermesRuntime> runtime_;
@@ -228,6 +246,19 @@ std::unique_ptr<StackTrace> HermesRuntimeTargetDelegate::captureStackTrace(
   return impl_->captureStackTrace(runtime, framesToSkip);
 }
 
+void HermesRuntimeTargetDelegate::enableSamplingProfiler() {
+  impl_->enableSamplingProfiler();
+}
+
+void HermesRuntimeTargetDelegate::disableSamplingProfiler() {
+  impl_->disableSamplingProfiler();
+}
+
+tracing::RuntimeSamplingProfile
+HermesRuntimeTargetDelegate::collectSamplingProfile() {
+  return impl_->collectSamplingProfile();
+}
+
 #ifdef HERMES_ENABLE_DEBUGGER
 CDPDebugAPI& HermesRuntimeTargetDelegate::getCDPDebugAPI() {
   return impl_->getCDPDebugAPI();

packages/react-native/ReactCommon/hermes/inspector-modern/chrome/HermesRuntimeTargetDelegate.h

@@ -54,6 +54,12 @@ class HermesRuntimeTargetDelegate : public RuntimeTargetDelegate {
       jsi::Runtime& runtime,
       size_t framesToSkip) override;
 
+  void enableSamplingProfiler() override;
+
+  void disableSamplingProfiler() override;
+
+  tracing::RuntimeSamplingProfile collectSamplingProfile() override;
+
  private:
   // We use the private implementation idiom to ensure this class has the same
   // layout regardless of whether HERMES_ENABLE_DEBUGGER is defined. The net

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

@@ -44,4 +44,18 @@ std::unique_ptr<StackTrace> FallbackRuntimeTargetDelegate::captureStackTrace(
   return std::make_unique<StackTrace>();
 }
 
+void FallbackRuntimeTargetDelegate::enableSamplingProfiler() {
+  // no-op
+};
+
+void FallbackRuntimeTargetDelegate::disableSamplingProfiler() {
+  // no-op
+};
+
+tracing::RuntimeSamplingProfile
+FallbackRuntimeTargetDelegate::collectSamplingProfile() {
+  throw std::logic_error(
+      "Sampling Profiler capabilities are not supported for Runtime fallback");
+}
+
 } // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/FallbackRuntimeTargetDelegate.h

@@ -40,6 +40,12 @@ class FallbackRuntimeTargetDelegate : public RuntimeTargetDelegate {
       jsi::Runtime& runtime,
       size_t framesToSkip) override;
 
+  void enableSamplingProfiler() override;
+
+  void disableSamplingProfiler() override;
+
+  tracing::RuntimeSamplingProfile collectSamplingProfile() override;
+
  private:
   std::string engineDescription_;
 };

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

@@ -223,8 +223,11 @@ void HostAgent::sendInfoLogEntry(
 
 void HostAgent::setCurrentInstanceAgent(
     std::shared_ptr<InstanceAgent> instanceAgent) {
+  tracingAgent_.setCurrentInstanceAgent(instanceAgent);
+
   auto previousInstanceAgent = std::move(instanceAgent_);
   instanceAgent_ = std::move(instanceAgent);
+
   if (!sessionState_.isRuntimeDomainEnabled) {
     return;
   }

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

@@ -152,4 +152,23 @@ void InstanceAgent::maybeSendPendingConsoleMessages() {
   }
 }
 
+void InstanceAgent::startTracing() {
+  if (runtimeAgent_) {
+    runtimeAgent_->enableSamplingProfiler();
+  }
+}
+
+void InstanceAgent::stopTracing() {
+  if (runtimeAgent_) {
+    runtimeAgent_->disableSamplingProfiler();
+  }
+}
+
+tracing::InstanceTracingProfile InstanceAgent::collectTracingProfile() {
+  tracing::RuntimeSamplingProfile runtimeSamplingProfile =
+      runtimeAgent_->collectSamplingProfile();
+
+  return tracing::InstanceTracingProfile{runtimeSamplingProfile};
+}
+
 } // namespace facebook::react::jsinspector_modern

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

@@ -13,6 +13,7 @@
 
 #include <jsinspector-modern/InspectorInterfaces.h>
 #include <jsinspector-modern/RuntimeAgent.h>
+#include <jsinspector-modern/tracing/InstanceTracingProfile.h>
 
 #include <functional>
 
@@ -59,6 +60,23 @@ class InstanceAgent final {
    */
   void sendConsoleMessage(SimpleConsoleMessage message);
 
+  /**
+   * Notify Instance about started Tracing session. Should be initiated by
+   * TracingAgent on Tracing.start CDP method.
+   */
+  void startTracing();
+
+  /**
+   * Notify Instance about stopped Tracing session. Should be initiated by
+   * TracingAgent on Tracing.end CDP method.
+   */
+  void stopTracing();
+
+  /**
+   * Return recorded profile for the previous tracing session.
+   */
+  tracing::InstanceTracingProfile collectTracingProfile();
+
  private:
   void maybeSendExecutionContextCreatedNotification();
   void sendConsoleMessageImmediately(SimpleConsoleMessage message);

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

@@ -149,4 +149,16 @@ RuntimeAgent::~RuntimeAgent() {
   sessionState_.lastRuntimeAgentExportedState = getExportedState();
 }
 
+void RuntimeAgent::enableSamplingProfiler() {
+  targetController_.enableSamplingProfiler();
+}
+
+void RuntimeAgent::disableSamplingProfiler() {
+  targetController_.disableSamplingProfiler();
+}
+
+tracing::RuntimeSamplingProfile RuntimeAgent::collectSamplingProfile() {
+  return targetController_.collectSamplingProfile();
+}
+
 } // namespace facebook::react::jsinspector_modern

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

@@ -12,6 +12,8 @@
 #include "RuntimeAgentDelegate.h"
 #include "RuntimeTarget.h"
 
+#include <jsinspector-modern/tracing/RuntimeSamplingProfile.h>
+
 namespace facebook::react::jsinspector_modern {
 
 class RuntimeTargetController;
@@ -81,6 +83,21 @@ class RuntimeAgent final {
    */
   ExportedState getExportedState();
 
+  /**
+   * Start sampling profiler for the corresponding RuntimeTarget.
+   */
+  void enableSamplingProfiler();
+
+  /**
+   * Stop sampling profiler for the corresponding RuntimeTarget.
+   */
+  void disableSamplingProfiler();
+
+  /**
+   * Return recorded sampling profile for the previous sampling session.
+   */
+  tracing::RuntimeSamplingProfile collectSamplingProfile();
+
  private:
   FrontendChannel frontendChannel_;
   RuntimeTargetController& targetController_;

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

@@ -159,4 +159,29 @@ void RuntimeTargetController::notifyDebuggerSessionDestroyed() {
   target_.emitDebuggerSessionDestroyed();
 }
 
+void RuntimeTargetController::enableSamplingProfiler() {
+  target_.enableSamplingProfiler();
+}
+
+void RuntimeTargetController::disableSamplingProfiler() {
+  target_.disableSamplingProfiler();
+}
+
+tracing::RuntimeSamplingProfile
+RuntimeTargetController::collectSamplingProfile() {
+  return target_.collectSamplingProfile();
+}
+
+void RuntimeTarget::enableSamplingProfiler() {
+  delegate_.enableSamplingProfiler();
+}
+
+void RuntimeTarget::disableSamplingProfiler() {
+  delegate_.disableSamplingProfiler();
+}
+
+tracing::RuntimeSamplingProfile RuntimeTarget::collectSamplingProfile() {
+  return delegate_.collectSamplingProfile();
+}
+
 } // namespace facebook::react::jsinspector_modern

packages/react-native/ReactCommon/jsinspector-modern/RuntimeTarget.h

@@ -7,8 +7,6 @@
 
 #pragma once
 
-#include <ReactCommon/RuntimeExecutor.h>
-
 #include "ConsoleMessage.h"
 #include "ExecutionContext.h"
 #include "InspectorInterfaces.h"
@@ -17,6 +15,9 @@
 #include "StackTrace.h"
 #include "WeakList.h"
 
+#include <ReactCommon/RuntimeExecutor.h>
+#include <jsinspector-modern/tracing/RuntimeSamplingProfile.h>
+
 #include <memory>
 
 #ifndef JSINSPECTOR_EXPORT
@@ -90,6 +91,21 @@ class RuntimeTargetDelegate {
   virtual std::unique_ptr<StackTrace> captureStackTrace(
       jsi::Runtime& runtime,
       size_t framesToSkip = 0) = 0;
+
+  /**
+   * Start sampling profiler.
+   */
+  virtual void enableSamplingProfiler() = 0;
+
+  /**
+   * Stop sampling profiler.
+   */
+  virtual void disableSamplingProfiler() = 0;
+
+  /**
+   * Return recorded sampling profile for the previous sampling session.
+   */
+  virtual tracing::RuntimeSamplingProfile collectSamplingProfile() = 0;
 };
 
 /**
@@ -118,6 +134,21 @@ class RuntimeTargetController {
    */
   void notifyDebuggerSessionDestroyed();
 
+  /**
+   * Start sampling profiler for the corresponding RuntimeTarget.
+   */
+  void enableSamplingProfiler();
+
+  /**
+   * Stop sampling profiler for the corresponding RuntimeTarget.
+   */
+  void disableSamplingProfiler();
+
+  /**
+   * Return recorded sampling profile for the previous sampling session.
+   */
+  tracing::RuntimeSamplingProfile collectSamplingProfile();
+
  private:
   RuntimeTarget& target_;
 };
@@ -171,6 +202,21 @@ class JSINSPECTOR_EXPORT RuntimeTarget
       FrontendChannel channel,
       SessionState& sessionState);
 
+  /**
+   * Start sampling profiler for a particular JavaScript runtime.
+   */
+  void enableSamplingProfiler();
+
+  /**
+   * Stop sampling profiler for a particular JavaScript runtime.
+   */
+  void disableSamplingProfiler();
+
+  /**
+   * Return recorded sampling profile for the previous sampling session.
+   */
+  tracing::RuntimeSamplingProfile collectSamplingProfile();
+
  private:
   /**
    * Constructs a new RuntimeTarget. The caller must call setExecutor

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

@@ -24,20 +24,44 @@ const uint16_t TRACE_EVENT_CHUNK_SIZE = 1000;
 bool TracingAgent::handleRequest(const cdp::PreparsedRequest& req) {
   if (req.method == "Tracing.start") {
     // @cdp Tracing.start support is experimental.
-    if (PerformanceTracer::getInstance().startTracing()) {
-      frontendChannel_(cdp::jsonResult(req.id));
-    } else {
+    if (!instanceAgent_) {
+      frontendChannel_(cdp::jsonError(
+          req.id,
+          cdp::ErrorCode::InternalError,
+          "Couldn't find instance available for Tracing"));
+
+      return true;
+    }
+
+    bool correctlyStartedPerformanceTracer =
+        PerformanceTracer::getInstance().startTracing();
+
+    if (!correctlyStartedPerformanceTracer) {
       frontendChannel_(cdp::jsonError(
           req.id,
           cdp::ErrorCode::InternalError,
           "Tracing session already started"));
+
+      return true;
     }
 
+    instanceAgent_->startTracing();
+    frontendChannel_(cdp::jsonResult(req.id));
+
     return true;
   } else if (req.method == "Tracing.end") {
     // @cdp Tracing.end support is experimental.
-    bool correctlyStopped = PerformanceTracer::getInstance().stopTracing();
+    if (!instanceAgent_) {
+      frontendChannel_(cdp::jsonError(
+          req.id,
+          cdp::ErrorCode::InternalError,
+          "Couldn't find instance available for Tracing"));
 
+      return true;
+    }
+    instanceAgent_->stopTracing();
+
+    bool correctlyStopped = PerformanceTracer::getInstance().stopTracing();
     if (!correctlyStopped) {
       frontendChannel_(cdp::jsonError(
           req.id,
@@ -68,4 +92,9 @@ bool TracingAgent::handleRequest(const cdp::PreparsedRequest& req) {
   return false;
 }
 
+void TracingAgent::setCurrentInstanceAgent(
+    std::shared_ptr<InstanceAgent> instanceAgent) {
+  instanceAgent_ = std::move(instanceAgent);
+}
+
 } // namespace facebook::react::jsinspector_modern