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<<b86b8bb1d53ca03240c25adb8b423040>>
+ * @generated SignedSource<<31638ef8ac6992a354785b74af8fbe0d>>
  */
 
 /**
@@ -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<<9c1e0e7e87aead96e2554ef5ecf9e7af>>
+ * @generated SignedSource<<6b382661025db56592b44255f5a8694c>>
  */
 
 /**
@@ -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<<b95c0d1f576b67fcf9d9df498ea30994>>
+ * @generated SignedSource<<8276fd1166cdd235f11a0b490bb7d924>>
  */
 
 /**
@@ -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<<c7425e6212e4e9d70e64452e550bf638>>
+ * @generated SignedSource<<ffadd7912aed2d95b0c6199aa8902690>>
  */
 
 /**
@@ -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<<5b145ee103cf6b40e13d33c88cd52777>>
+ * @generated SignedSource<<5dc41059d71d3a345be45a6a233b05a0>>
  */
 
 /**
@@ -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<<9cdb965a420d53cf36b6531684cb07ae>>
+ * @generated SignedSource<<35f6d9ae3c445c81fc4bab7509fd3179>>
  */
 
 /**
@@ -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<<c89831646046b10c7b2a40e14deb3d1a>>
+ * @generated SignedSource<<d566c157b7db07e235bada071067f11d>>
  */
 
 /**
@@ -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<<2a5ad62d2cb4f1111391f1b566e10c1d>>
+ * @generated SignedSource<<270b461fa199f8e6365948cded0785ad>>
  */
 
 /**
@@ -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<<0eb63ead191be88440cbb73fd760dec7>>
+ * @generated SignedSource<<74f22c6a0302a9923e99d2455d84e231>>
  */
 
 /**
@@ -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<<80dcd75591a392144c2fd2817cc4408a>>
+ * @generated SignedSource<<b941543bc6f12dbb0e12ac2ae0042186>>
  */
 
 /**
@@ -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.
    */