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<<991cfdadfc26e470da425a986d75c766>>
+ * @generated SignedSource<<416e60f0ed13027fcd2586b15916d98a>>
  */
 
 /**
@@ -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<<65268cf15face782370694a2a5bd8c3f>>
+ * @generated SignedSource<<c9c74b0ad68b3b4d50471c3299c13ba9>>
  */
 
 /**
@@ -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
@@ -157,6 +158,15 @@ 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<<6650ca57c9b43c16506ea8a95cf95b8a>>
+ * @generated SignedSource<<f8fbadb52c5645f54e14d6f2cd1490c5>>
  */
 
 /**
@@ -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<<906ab78c1c4099bc4711c102885becd0>>
+ * @generated SignedSource<<a56643b81ee5e53a4f13f11c865bd929>>
  */
 
 /**
@@ -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<<aa86a9c0807638f1f44ced69462b1d17>>
+ * @generated SignedSource<<8da35e9ec869f321b417b41a81b95513>>
  */
 
 /**
@@ -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
@@ -171,6 +172,16 @@ 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<<bad6f4d9b4c7ba419c2ad37a5089c3e7>>
+ * @generated SignedSource<<2b5bef41a6f2000751f2e94976196e87>>
  */
 
 /**
@@ -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<<65232e117b548982fd5c59502599b1bb>>
+ * @generated SignedSource<<1ac26b645f1e71a31acef8f827e87b52>>
  */
 
 /**
@@ -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");
@@ -369,6 +375,11 @@ 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();
@@ -610,6 +621,9 @@ 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<<980b6545944b8053fbe9901d3e4746ee>>
+ * @generated SignedSource<<38d2d525708cbd8ac5d19004df2700c3>>
  */
 
 /**
@@ -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<<7929b1ed09571f4afd84196d8c672615>>
+ * @generated SignedSource<<be20e25a66baf1bf5004875adac8496c>>
  */
 
 /**
@@ -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<<0588d6b7fda4af37b3ba8ec5ad88657b>>
+ * @generated SignedSource<<4f2e74a54a95d58283bdf369b616106e>>
  */
 
 /**
@@ -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.
    */