Set up experiment to fix incorrect state updates in smooth scroll animations on Android

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<9a33a6bc10cdb2b0f9fcb15805a06982>>
+ * @generated SignedSource<<1cad606bd06ab650004955138228d227>>
  */
 
 /**
@@ -94,12 +94,24 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableUIConsistency(): Boolean = accessor.enableUIConsistency()
 
+  /**
+   * When doing a smooth scroll animation, it stops setting the state with the final scroll position in Fabric before the animation starts.
+   */
+  @JvmStatic
+  public fun fixIncorrectScrollViewStateUpdateOnAndroid(): Boolean = accessor.fixIncorrectScrollViewStateUpdateOnAndroid()
+
   /**
    * Uses the default event priority instead of the discreet event priority by default when dispatching events from Fabric to React.
    */
   @JvmStatic
   public fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean = accessor.fixMappingOfEventPrioritiesBetweenFabricAndReact()
 
+  /**
+   * Enables a fix to prevent the possibility of state updates in Fabric being missed due to race conditions with previous state updates.
+   */
+  @JvmStatic
+  public fun fixMissedFabricStateUpdatesOnAndroid(): Boolean = accessor.fixMissedFabricStateUpdatesOnAndroid()
+
   /**
    * Fixes a leak in SurfaceMountingManager.mRemoveDeleteTreeUIFrameCallback
    */

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<5d67280406c16b01ba71b7b75e814a79>>
+ * @generated SignedSource<<b03fe019d1bacd13740a3e783197c17b>>
  */
 
 /**
@@ -31,7 +31,9 @@ public class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAccesso
   private var enableMicrotasksCache: Boolean? = null
   private var enableSynchronousStateUpdatesCache: Boolean? = null
   private var enableUIConsistencyCache: Boolean? = null
+  private var fixIncorrectScrollViewStateUpdateOnAndroidCache: Boolean? = null
   private var fixMappingOfEventPrioritiesBetweenFabricAndReactCache: Boolean? = null
+  private var fixMissedFabricStateUpdatesOnAndroidCache: Boolean? = null
   private var fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeakCache: Boolean? = null
   private var forceBatchingMountItemsOnAndroidCache: Boolean? = null
   private var fuseboxEnabledDebugCache: Boolean? = null
@@ -145,6 +147,15 @@ public class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAccesso
     return cached
   }
 
+  override fun fixIncorrectScrollViewStateUpdateOnAndroid(): Boolean {
+    var cached = fixIncorrectScrollViewStateUpdateOnAndroidCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.fixIncorrectScrollViewStateUpdateOnAndroid()
+      fixIncorrectScrollViewStateUpdateOnAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean {
     var cached = fixMappingOfEventPrioritiesBetweenFabricAndReactCache
     if (cached == null) {
@@ -154,6 +165,15 @@ public class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAccesso
     return cached
   }
 
+  override fun fixMissedFabricStateUpdatesOnAndroid(): Boolean {
+    var cached = fixMissedFabricStateUpdatesOnAndroidCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.fixMissedFabricStateUpdatesOnAndroid()
+      fixMissedFabricStateUpdatesOnAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeak(): Boolean {
     var cached = fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeakCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<154baea748cdf7b8e05a1e4448053673>>
+ * @generated SignedSource<<1b39ae121d8238bbb34c54330700c9e8>>
  */
 
 /**
@@ -50,8 +50,12 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableUIConsistency(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun fixIncorrectScrollViewStateUpdateOnAndroid(): Boolean
+
   @DoNotStrip @JvmStatic public external fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun fixMissedFabricStateUpdatesOnAndroid(): Boolean
+
   @DoNotStrip @JvmStatic public external fun fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeak(): Boolean
 
   @DoNotStrip @JvmStatic public external fun forceBatchingMountItemsOnAndroid(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<34bbd584a612fa88cc6adf2d2bc51b92>>
+ * @generated SignedSource<<0584cef0a5e682b2b3ba6d46161e0286>>
  */
 
 /**
@@ -45,8 +45,12 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableUIConsistency(): Boolean = false
 
+  override fun fixIncorrectScrollViewStateUpdateOnAndroid(): Boolean = false
+
   override fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean = false
 
+  override fun fixMissedFabricStateUpdatesOnAndroid(): Boolean = false
+
   override fun fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeak(): Boolean = false
 
   override fun forceBatchingMountItemsOnAndroid(): Boolean = false

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsLocalAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<d991cac9311ee91e5e9401b143b69145>>
+ * @generated SignedSource<<a97af69ca22746594d72410f72a0a1cb>>
  */
 
 /**
@@ -35,7 +35,9 @@ public class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcces
   private var enableMicrotasksCache: Boolean? = null
   private var enableSynchronousStateUpdatesCache: Boolean? = null
   private var enableUIConsistencyCache: Boolean? = null
+  private var fixIncorrectScrollViewStateUpdateOnAndroidCache: Boolean? = null
   private var fixMappingOfEventPrioritiesBetweenFabricAndReactCache: Boolean? = null
+  private var fixMissedFabricStateUpdatesOnAndroidCache: Boolean? = null
   private var fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeakCache: Boolean? = null
   private var forceBatchingMountItemsOnAndroidCache: Boolean? = null
   private var fuseboxEnabledDebugCache: Boolean? = null
@@ -160,6 +162,16 @@ public class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun fixIncorrectScrollViewStateUpdateOnAndroid(): Boolean {
+    var cached = fixIncorrectScrollViewStateUpdateOnAndroidCache
+    if (cached == null) {
+      cached = currentProvider.fixIncorrectScrollViewStateUpdateOnAndroid()
+      accessedFeatureFlags.add("fixIncorrectScrollViewStateUpdateOnAndroid")
+      fixIncorrectScrollViewStateUpdateOnAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean {
     var cached = fixMappingOfEventPrioritiesBetweenFabricAndReactCache
     if (cached == null) {
@@ -170,6 +182,16 @@ public class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun fixMissedFabricStateUpdatesOnAndroid(): Boolean {
+    var cached = fixMissedFabricStateUpdatesOnAndroidCache
+    if (cached == null) {
+      cached = currentProvider.fixMissedFabricStateUpdatesOnAndroid()
+      accessedFeatureFlags.add("fixMissedFabricStateUpdatesOnAndroid")
+      fixMissedFabricStateUpdatesOnAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeak(): Boolean {
     var cached = fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeakCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<aae9b8936680c1cd6db2c1c0135e1cef>>
+ * @generated SignedSource<<de2cd46cfe4a934b6584e782c4d9d213>>
  */
 
 /**
@@ -45,8 +45,12 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableUIConsistency(): Boolean
 
+  @DoNotStrip public fun fixIncorrectScrollViewStateUpdateOnAndroid(): Boolean
+
   @DoNotStrip public fun fixMappingOfEventPrioritiesBetweenFabricAndReact(): Boolean
 
+  @DoNotStrip public fun fixMissedFabricStateUpdatesOnAndroid(): Boolean
+
   @DoNotStrip public fun fixStoppedSurfaceRemoveDeleteTreeUIFrameCallbackLeak(): Boolean
 
   @DoNotStrip public fun forceBatchingMountItemsOnAndroid(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollViewHelper.kt

@@ -19,6 +19,7 @@ import com.facebook.react.bridge.ReactContext
 import com.facebook.react.bridge.WritableMap
 import com.facebook.react.bridge.WritableNativeMap
 import com.facebook.react.common.ReactConstants
+import com.facebook.react.internal.featureflags.ReactNativeFeatureFlags
 import com.facebook.react.uimanager.PixelUtil.toDIPFromPixel
 import com.facebook.react.uimanager.StateWrapper
 import com.facebook.react.uimanager.UIManagerHelper
@@ -249,7 +250,9 @@ public object ReactScrollViewHelper {
     if (scrollY != y) {
       scrollView.startFlingAnimator(scrollY, y)
     }
-    updateFabricScrollState<T>(scrollView, x, y)
+    if (ReactNativeFeatureFlags.fixIncorrectScrollViewStateUpdateOnAndroid()) {
+      updateFabricScrollState<T>(scrollView, x, y)
+    }
   }
 
   /** Get current position or position after current animation finishes, if any. */

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

@@ -540,7 +540,7 @@ void FabricMountingManager::executeMount(
       if (mountItem.newChildShadowView.state != nullptr) {
         javaStateWrapper = StateWrapperImpl::newObjectJavaArgs();
         StateWrapperImpl* cStateWrapper = cthis(javaStateWrapper);
-        cStateWrapper->state_ = mountItem.newChildShadowView.state;
+        cStateWrapper->setState(mountItem.newChildShadowView.state);
       }
 
       // Do not hold a reference to javaEventEmitter from the C++ side.
@@ -615,7 +615,7 @@ void FabricMountingManager::executeMount(
       if (state != nullptr) {
         javaStateWrapper = StateWrapperImpl::newObjectJavaArgs();
         StateWrapperImpl* cStateWrapper = cthis(javaStateWrapper);
-        cStateWrapper->state_ = state;
+        cStateWrapper->setState(state);
       }
 
       (*objBufferArray)[objBufferPosition++] =
@@ -823,7 +823,7 @@ void FabricMountingManager::preallocateShadowView(
   if (shadowView.state != nullptr) {
     javaStateWrapper = StateWrapperImpl::newObjectJavaArgs();
     StateWrapperImpl* cStateWrapper = cthis(javaStateWrapper);
-    cStateWrapper->state_ = shadowView.state;
+    cStateWrapper->setState(shadowView.state);
   }
 
   // Do not hold a reference to javaEventEmitter from the C++ side.

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

@@ -7,6 +7,7 @@
 
 #include "StateWrapperImpl.h"
 #include <fbjni/fbjni.h>
+#include <react/featureflags/ReactNativeFeatureFlags.h>
 #include <react/jni/ReadableNativeMap.h>
 #include <react/renderer/mapbuffer/MapBuffer.h>
 #include <react/renderer/mapbuffer/MapBufferBuilder.h>
@@ -25,30 +26,65 @@ jni::local_ref<StateWrapperImpl::jhybriddata> StateWrapperImpl::initHybrid(
 
 jni::local_ref<ReadableNativeMap::jhybridobject>
 StateWrapperImpl::getStateDataImpl() {
-  if (auto state = state_.lock()) {
-    folly::dynamic map = state->getDynamic();
-    return ReadableNativeMap::newObjectCxxArgs(std::move(map));
+  if (ReactNativeFeatureFlags::fixMissedFabricStateUpdatesOnAndroid()) {
+    if (state_) {
+      folly::dynamic map = state_->getDynamic();
+      return ReadableNativeMap::newObjectCxxArgs(std::move(map));
+    } else {
+      return nullptr;
+    }
   } else {
-    return nullptr;
+    if (auto state = weakState_.lock()) {
+      folly::dynamic map = state->getDynamic();
+      return ReadableNativeMap::newObjectCxxArgs(std::move(map));
+    } else {
+      return nullptr;
+    }
   }
 }
 
 jni::local_ref<JReadableMapBuffer::jhybridobject>
 StateWrapperImpl::getStateMapBufferDataImpl() {
-  if (auto state = state_.lock()) {
-    MapBuffer map = state->getMapBuffer();
-    return JReadableMapBuffer::createWithContents(std::move(map));
+  if (ReactNativeFeatureFlags::fixMissedFabricStateUpdatesOnAndroid()) {
+    if (state_) {
+      MapBuffer map = state_->getMapBuffer();
+      return JReadableMapBuffer::createWithContents(std::move(map));
+    } else {
+      return nullptr;
+    }
   } else {
-    return nullptr;
+    if (auto state = weakState_.lock()) {
+      MapBuffer map = state->getMapBuffer();
+      return JReadableMapBuffer::createWithContents(std::move(map));
+    } else {
+      return nullptr;
+    }
   }
 }
 
 void StateWrapperImpl::updateStateImpl(NativeMap* map) {
-  if (auto state = state_.lock()) {
-    // Get folly::dynamic from map
-    auto dynamicMap = map->consume();
-    // Set state
-    state->updateState(std::move(dynamicMap));
+  if (ReactNativeFeatureFlags::fixMissedFabricStateUpdatesOnAndroid()) {
+    if (state_) {
+      // Get folly::dynamic from map
+      auto dynamicMap = map->consume();
+      // Set state
+      state_->updateState(std::move(dynamicMap));
+    }
+  } else {
+    if (auto state = weakState_.lock()) {
+      // Get folly::dynamic from map
+      auto dynamicMap = map->consume();
+      // Set state
+      state->updateState(std::move(dynamicMap));
+    }
+  }
+}
+
+void StateWrapperImpl::setState(std::shared_ptr<const State> state) {
+  if (ReactNativeFeatureFlags::fixMissedFabricStateUpdatesOnAndroid()) {
+    state_ = state;
+  } else {
+    weakState_ = state;
   }
 }
 

packages/react-native/ReactAndroid/src/main/jni/react/fabric/StateWrapperImpl.h

@@ -28,11 +28,12 @@ class StateWrapperImpl : public jni::HybridClass<StateWrapperImpl> {
   jni::local_ref<JReadableMapBuffer::jhybridobject> getStateMapBufferDataImpl();
   jni::local_ref<ReadableNativeMap::jhybridobject> getStateDataImpl();
   void updateStateImpl(NativeMap* map);
-
-  std::weak_ptr<const State> state_;
+  void setState(std::shared_ptr<const State> state);
 
  private:
   jni::alias_ref<StateWrapperImpl::jhybriddata> jhybridobject_;
+  std::weak_ptr<const State> weakState_;
+  std::shared_ptr<const State> state_;
 
   static jni::local_ref<jhybriddata> initHybrid(jni::alias_ref<jclass>);
 };