Add feature flag to use JSI NativeState instead of HostObject (#36395)

Summary:
Pull Request resolved: #36395

NativeState is a lighter-weight alternative to HostObject, which may simplify some of our use-cases of interacting with JS in the renderer. The down-side is that this approach doesn't allow exposing custom props or functions.

This diffs adds new feature flags to enable experimenting with this functionality and measure any perf impact.

Changelog: [Internal]

Reviewed By: sammy-SC

Differential Revision: D41553421

fbshipit-source-id: 1a8f252b6910384d7a1a5699c2cca0b69e0c74ca

Author: javache

React/Fabric/RCTSurfacePresenter.mm

@@ -277,6 +277,10 @@ - (RCTScheduler *)_createScheduler
     CoreFeatures::enablePropIteratorSetter = true;
   }
 
+  if (reactNativeConfig && reactNativeConfig->getBool("react_fabric:use_native_state")) {
+    CoreFeatures::useNativeState = true;
+  }
+
   auto componentRegistryFactory =
       [factory = wrapManagedObject(_mountingManager.componentViewRegistry.componentViewFactory)](
           EventDispatcher::Weak const &eventDispatcher, ContextContainer::Shared const &contextContainer) {

ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java

@@ -118,4 +118,10 @@ public class ReactFeatureFlags {
    * SurfaceMountingManager.
    */
   public static boolean reduceDeleteCreateMutation = false;
+
+  /**
+   * Use JSI NativeState API to store references to native objects rather than the more expensive
+   * HostObject pattern
+   */
+  public static boolean useNativeState = false;
 }

ReactAndroid/src/main/jni/react/fabric/Binding.cpp

@@ -433,6 +433,9 @@ void Binding::installFabricUIManager(
   CoreFeatures::enablePropIteratorSetter =
       getFeatureFlagValue("enableCppPropsIteratorSetter");
 
+  // NativeState experiment
+  CoreFeatures::useNativeState = getFeatureFlagValue("useNativeState");
+
   // RemoveDelete mega-op
   ShadowViewMutation::PlatformSupportsRemoveDeleteTreeInstruction =
       getFeatureFlagValue("enableRemoveDeleteTreeInstruction");

ReactCommon/react/renderer/core/CoreFeatures.cpp

@@ -13,6 +13,7 @@ namespace react {
 bool CoreFeatures::enablePropIteratorSetter = false;
 bool CoreFeatures::enableMapBuffer = false;
 bool CoreFeatures::blockPaintForUseLayoutEffect = false;
+bool CoreFeatures::useNativeState = false;
 
 } // namespace react
 } // namespace facebook

ReactCommon/react/renderer/core/CoreFeatures.h

@@ -30,6 +30,10 @@ class CoreFeatures {
   // useLayoutEffect hooks to be processed. This changes affects scheduling of
   // when a transaction is mounted.
   static bool blockPaintForUseLayoutEffect;
+
+  // Whether to use Hermes' NativeState instead of HostObject
+  // in simple data passing scenarios with JS
+  static bool useNativeState;
 };
 
 } // namespace react

ReactCommon/react/renderer/core/ShadowNode.h

@@ -29,7 +29,9 @@ static constexpr const int kShadowNodeChildrenSmallVectorSize = 8;
 class ComponentDescriptor;
 struct ShadowNodeFragment;
 
-class ShadowNode : public Sealable, public DebugStringConvertible {
+class ShadowNode : public Sealable,
+                   public DebugStringConvertible,
+                   public jsi::NativeState {
  public:
   using Shared = std::shared_ptr<ShadowNode const>;
   using Weak = std::weak_ptr<ShadowNode const>;

ReactCommon/react/renderer/graphics/BUCK

@@ -8,7 +8,6 @@ load(
     "get_apple_compiler_flags",
     "get_apple_inspector_flags",
     "get_preprocessor_flags_for_build_mode",
-    "react_native_target",
     "react_native_xplat_target",
     "rn_xplat_cxx_library",
     "subdir_glob",
@@ -53,7 +52,7 @@ rn_xplat_cxx_library(
     fbandroid_allow_jni_merging = True,
     fbandroid_deps = [
         FBJNI_TARGET,
-        react_native_target("jni/react/jni:jni"),
+        "//xplat/folly:dynamic",
     ],
     fbandroid_exported_headers = subdir_glob(
         [

ReactCommon/react/renderer/runtimescheduler/BUCK

@@ -49,6 +49,7 @@ rn_xplat_cxx_library(
     deps = [
         "//xplat/folly:dynamic",
         react_native_xplat_target("runtimeexecutor:runtimeexecutor"),
+        react_native_xplat_target("react/renderer/core:core"),
         react_native_xplat_target("react/renderer/debug:debug"),
         react_native_xplat_target("butter:butter"),
         react_native_xplat_target("callinvoker:callinvoker"),

ReactCommon/react/renderer/runtimescheduler/Task.h

@@ -21,7 +21,7 @@ class TaskPriorityComparer;
 
 using RawCallback = std::function<void(jsi::Runtime &)>;
 
-struct Task final {
+struct Task final : public jsi::NativeState {
   Task(
       SchedulerPriority priority,
       jsi::Function callback,

ReactCommon/react/renderer/runtimescheduler/primitives.h

@@ -9,6 +9,7 @@
 
 #include <folly/dynamic.h>
 #include <jsi/jsi.h>
+#include <react/renderer/core/CoreFeatures.h>
 #include <react/renderer/runtimescheduler/Task.h>
 
 namespace facebook {
@@ -22,9 +23,15 @@ struct TaskWrapper : public jsi::HostObject {
 
 inline static jsi::Value valueFromTask(
     jsi::Runtime &runtime,
-    std::shared_ptr<Task> const &task) {
-  return jsi::Object::createFromHostObject(
-      runtime, std::make_shared<TaskWrapper>(task));
+    std::shared_ptr<Task> task) {
+  if (CoreFeatures::useNativeState) {
+    jsi::Object obj(runtime);
+    obj.setNativeState(runtime, std::move(task));
+    return obj;
+  } else {
+    return jsi::Object::createFromHostObject(
+        runtime, std::make_shared<TaskWrapper>(task));
+  }
 }
 
 inline static std::shared_ptr<Task> taskFromValue(
@@ -34,7 +41,11 @@ inline static std::shared_ptr<Task> taskFromValue(
     return nullptr;
   }
 
-  return value.getObject(runtime).getHostObject<TaskWrapper>(runtime)->task;
+  if (CoreFeatures::useNativeState) {
+    return value.getObject(runtime).getNativeState<Task>(runtime);
+  } else {
+    return value.getObject(runtime).getHostObject<TaskWrapper>(runtime)->task;
+  }
 }
 
 } // namespace react