Delete ShadowTreeRevision on background thread (#50997)

Summary:
Pull Request resolved: #50997

In some apps, we spend a non-trivial amount of time calling ShadowNode destructors on the UI thread.

A simple way to avoid stalling the UI thread is to move the `baseRevision_` instance to a data structure that is cleared on a background thread, so it's tree of ShadowNode shared_ptrs are released (and in most cases destroyed) on the background thread.

Rather than using std::thread, this change introduces the LowPriorityExecutor abstraction that should be supplied by host platforms. The implementation of this LowPriorityExecutor for each platform is as follows:
- iOS: uses dispatch_async to a low priority dispatch queue
- Android: uses a pthread with SCHED_OTHER and priority = 19

Moving the ShadowTreeRevision into a lambda capture and punting the lambda to the LowPriorityExecutor moves the destructor calls of the ShadowNodes to the host platform implementation of the LowPriorityExecutor.

This change is also guarded by a feature flag so we can keep an eye out for potential memory leaks.

## Changelog

[Internal]

Reviewed By: NickGerleman

Differential Revision: D73688009

Author: rozele

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<<62ec58d76b9e14b3e1e4e10e62fc196a>>
+ * @generated SignedSource<<a31885acf3f5f3b02253ee810e7e2bcd>>
  */
 
 /**
@@ -90,6 +90,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableCustomFocusSearchOnClippedElementsAndroid(): Boolean = accessor.enableCustomFocusSearchOnClippedElementsAndroid()
 
+  /**
+   * Enables destructor calls for ShadowTreeRevision in the background to reduce UI thread work.
+   */
+  @JvmStatic
+  public fun enableDestroyShadowTreeRevisionAsync(): Boolean = accessor.enableDestroyShadowTreeRevisionAsync()
+
   /**
    * When enabled a subset of components will avoid double measurement on Android.
    */

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<<03596dcddbe8976adfcf454b9b35e3c3>>
+ * @generated SignedSource<<a3266a2ff824d99240b8d0652cba2d26>>
  */
 
 /**
@@ -30,6 +30,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var enableBridgelessArchitectureCache: Boolean? = null
   private var enableCppPropsIteratorSetterCache: Boolean? = null
   private var enableCustomFocusSearchOnClippedElementsAndroidCache: Boolean? = null
+  private var enableDestroyShadowTreeRevisionAsyncCache: Boolean? = null
   private var enableDoubleMeasurementFixAndroidCache: Boolean? = null
   private var enableEagerRootViewAttachmentCache: Boolean? = null
   private var enableFabricLogsCache: Boolean? = null
@@ -156,6 +157,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun enableDestroyShadowTreeRevisionAsync(): Boolean {
+    var cached = enableDestroyShadowTreeRevisionAsyncCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.enableDestroyShadowTreeRevisionAsync()
+      enableDestroyShadowTreeRevisionAsyncCache = cached
+    }
+    return cached
+  }
+
   override fun enableDoubleMeasurementFixAndroid(): Boolean {
     var cached = enableDoubleMeasurementFixAndroidCache
     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<<eeeeed4a48a3627d5d51635da9c15cb7>>
+ * @generated SignedSource<<e864a58b57069c96819b94081e466893>>
  */
 
 /**
@@ -48,6 +48,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableCustomFocusSearchOnClippedElementsAndroid(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun enableDestroyShadowTreeRevisionAsync(): Boolean
+
   @DoNotStrip @JvmStatic public external fun enableDoubleMeasurementFixAndroid(): Boolean
 
   @DoNotStrip @JvmStatic public external fun enableEagerRootViewAttachment(): 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<<7d343ae73a15daf1a4d8d85ba959dd81>>
+ * @generated SignedSource<<9477b557c75477041d05d8a842f4c97a>>
  */
 
 /**
@@ -43,6 +43,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableCustomFocusSearchOnClippedElementsAndroid(): Boolean = true
 
+  override fun enableDestroyShadowTreeRevisionAsync(): Boolean = false
+
   override fun enableDoubleMeasurementFixAndroid(): Boolean = false
 
   override fun enableEagerRootViewAttachment(): 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<<f4ae0172bfb1c4d64213c0cd14320bdd>>
+ * @generated SignedSource<<bb808a422c37e8766ec620f15550b72f>>
  */
 
 /**
@@ -34,6 +34,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var enableBridgelessArchitectureCache: Boolean? = null
   private var enableCppPropsIteratorSetterCache: Boolean? = null
   private var enableCustomFocusSearchOnClippedElementsAndroidCache: Boolean? = null
+  private var enableDestroyShadowTreeRevisionAsyncCache: Boolean? = null
   private var enableDoubleMeasurementFixAndroidCache: Boolean? = null
   private var enableEagerRootViewAttachmentCache: Boolean? = null
   private var enableFabricLogsCache: Boolean? = null
@@ -170,6 +171,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun enableDestroyShadowTreeRevisionAsync(): Boolean {
+    var cached = enableDestroyShadowTreeRevisionAsyncCache
+    if (cached == null) {
+      cached = currentProvider.enableDestroyShadowTreeRevisionAsync()
+      accessedFeatureFlags.add("enableDestroyShadowTreeRevisionAsync")
+      enableDestroyShadowTreeRevisionAsyncCache = cached
+    }
+    return cached
+  }
+
   override fun enableDoubleMeasurementFixAndroid(): Boolean {
     var cached = enableDoubleMeasurementFixAndroidCache
     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<<3b830939241e6fde03e6e63faa7232ff>>
+ * @generated SignedSource<<61e0ae1026e903d9934abc118149a56f>>
  */
 
 /**
@@ -43,6 +43,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableCustomFocusSearchOnClippedElementsAndroid(): Boolean
 
+  @DoNotStrip public fun enableDestroyShadowTreeRevisionAsync(): Boolean
+
   @DoNotStrip public fun enableDoubleMeasurementFixAndroid(): Boolean
 
   @DoNotStrip public fun enableEagerRootViewAttachment(): Boolean

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp

@@ -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<<a176560c48267f25dd8fdb5a1a232d37>>
+ * @generated SignedSource<<4bf2735cbae23f4c465fe703c6229326>>
  */
 
 /**
@@ -99,6 +99,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool enableDestroyShadowTreeRevisionAsync() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableDestroyShadowTreeRevisionAsync");
+    return method(javaProvider_);
+  }
+
   bool enableDoubleMeasurementFixAndroid() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableDoubleMeasurementFixAndroid");
@@ -363,6 +369,11 @@ bool JReactNativeFeatureFlagsCxxInterop::enableCustomFocusSearchOnClippedElement
   return ReactNativeFeatureFlags::enableCustomFocusSearchOnClippedElementsAndroid();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::enableDestroyShadowTreeRevisionAsync(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::enableDestroyShadowTreeRevisionAsync();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::enableDoubleMeasurementFixAndroid(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::enableDoubleMeasurementFixAndroid();
@@ -599,6 +610,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "enableCustomFocusSearchOnClippedElementsAndroid",
         JReactNativeFeatureFlagsCxxInterop::enableCustomFocusSearchOnClippedElementsAndroid),
+      makeNativeMethod(
+        "enableDestroyShadowTreeRevisionAsync",
+        JReactNativeFeatureFlagsCxxInterop::enableDestroyShadowTreeRevisionAsync),
       makeNativeMethod(
         "enableDoubleMeasurementFixAndroid",
         JReactNativeFeatureFlagsCxxInterop::enableDoubleMeasurementFixAndroid),

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h

@@ -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<<dae3956726e1cbbb2b78d9fffaeca6dd>>
+ * @generated SignedSource<<234bfb4702e420ea5ea51757eb7a92da>>
  */
 
 /**
@@ -60,6 +60,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool enableCustomFocusSearchOnClippedElementsAndroid(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool enableDestroyShadowTreeRevisionAsync(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool enableDoubleMeasurementFixAndroid(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp

@@ -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<<42e3fd2958733abb652f73d87b5b4a7d>>
+ * @generated SignedSource<<b1e7b65c583107641b52335a22be94d4>>
  */
 
 /**
@@ -66,6 +66,10 @@ bool ReactNativeFeatureFlags::enableCustomFocusSearchOnClippedElementsAndroid()
   return getAccessor().enableCustomFocusSearchOnClippedElementsAndroid();
 }
 
+bool ReactNativeFeatureFlags::enableDestroyShadowTreeRevisionAsync() {
+  return getAccessor().enableDestroyShadowTreeRevisionAsync();
+}
+
 bool ReactNativeFeatureFlags::enableDoubleMeasurementFixAndroid() {
   return getAccessor().enableDoubleMeasurementFixAndroid();
 }

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h

@@ -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<<871f96445659d2f927efeda5480b6f96>>
+ * @generated SignedSource<<9989109db32cd6d944ac77da6843f8e4>>
  */
 
 /**
@@ -89,6 +89,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool enableCustomFocusSearchOnClippedElementsAndroid();
 
+  /**
+   * Enables destructor calls for ShadowTreeRevision in the background to reduce UI thread work.
+   */
+  RN_EXPORT static bool enableDestroyShadowTreeRevisionAsync();
+
   /**
    * When enabled a subset of components will avoid double measurement on Android.
    */