Default to AsynchronousBatched priority (#39011)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/39011

Changelog: [internal]

Reviewed By: sammy-SC

Differential Revision: D48210134

fbshipit-source-id: aac2aec11c35dd6a47bc8fd4bf74f2fa00ab3d7e

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java

@@ -160,4 +160,7 @@ public class ReactFeatureFlags {
 
   /** Clean yoga node when <Text /> does not change. */
   public static boolean enableCleanParagraphYogaNode = false;
+
+  /** Default state updates and events to async batched priority. */
+  public static boolean enableDefaultAsyncBatchedPriority = false;
 }

packages/react-native/ReactAndroid/src/main/jni/react/fabric/Binding.cpp

@@ -435,6 +435,8 @@ void Binding::installFabricUIManager(
       getFeatureFlagValue("doNotSwapLeftAndRightOnAndroidInLTR");
   CoreFeatures::enableCleanParagraphYogaNode =
       getFeatureFlagValue("enableCleanParagraphYogaNode");
+  CoreFeatures::enableDefaultAsyncBatchedPriority =
+      getFeatureFlagValue("enableDefaultAsyncBatchedPriority");
 
   // RemoveDelete mega-op
   ShadowViewMutation::PlatformSupportsRemoveDeleteTreeInstruction =

packages/react-native/ReactCommon/react/renderer/components/view/BaseViewEventEmitter.cpp

@@ -6,6 +6,7 @@
  */
 
 #include "BaseViewEventEmitter.h"
+#include <react/utils/CoreFeatures.h>
 
 namespace facebook::react {
 
@@ -112,7 +113,9 @@ void BaseViewEventEmitter::onLayout(const LayoutMetrics &layoutMetrics) const {
         payload.setProperty(runtime, "layout", std::move(layout));
         return jsi::Value(std::move(payload));
       },
-      EventPriority::AsynchronousUnbatched);
+      CoreFeatures::enableDefaultAsyncBatchedPriority
+          ? EventPriority::AsynchronousBatched
+          : EventPriority::AsynchronousUnbatched);
 }
 
 } // namespace facebook::react

packages/react-native/ReactCommon/react/renderer/core/ConcreteState.h

@@ -12,6 +12,7 @@
 
 #include <react/debug/react_native_assert.h>
 #include <react/renderer/core/State.h>
+#include <react/utils/CoreFeatures.h>
 
 namespace facebook::react {
 
@@ -58,9 +59,7 @@ class ConcreteState : public State {
    * function for cases where a new value of data does not depend on an old
    * value.
    */
-  void updateState(
-      Data &&newData,
-      EventPriority priority = EventPriority::AsynchronousUnbatched) const {
+  void updateState(Data &&newData, EventPriority priority) const {
     updateState(
         [data{std::move(newData)}](Data const &oldData) -> SharedData {
           return std::make_shared<Data const>(data);
@@ -68,6 +67,14 @@ class ConcreteState : public State {
         priority);
   }
 
+  void updateState(Data &&newData) const {
+    updateState(
+        std::move(newData),
+        CoreFeatures::enableDefaultAsyncBatchedPriority
+            ? EventPriority::AsynchronousBatched
+            : EventPriority::AsynchronousUnbatched);
+  }
+
   /*
    * Initiate a state update process with a given function (that transforms an
    * old data value to a new one) and priority. The callback function can be

packages/react-native/ReactCommon/react/utils/CoreFeatures.cpp

@@ -21,5 +21,6 @@ bool CoreFeatures::doNotSwapLeftAndRightOnAndroidInLTR = false;
 bool CoreFeatures::enableCleanParagraphYogaNode = false;
 bool CoreFeatures::disableScrollEventThrottleRequirement = false;
 bool CoreFeatures::enableGranularShadowTreeStateReconciliation = false;
+bool CoreFeatures::enableDefaultAsyncBatchedPriority = false;
 
 } // namespace facebook::react

packages/react-native/ReactCommon/react/utils/CoreFeatures.h

@@ -64,6 +64,9 @@ class CoreFeatures {
   // When enabled, the renderer would only fail commits when they propagate
   // state and the last commit that updated state changed before committing.
   static bool enableGranularShadowTreeStateReconciliation;
+
+  // Default state updates and events to async batched priority.
+  static bool enableDefaultAsyncBatchedPriority;
 };
 
 } // namespace facebook::react