Collect orphaned AnimatedPropsRegistry entry on last animated view unmount

An in-flight worklet frame can re-add an unmounting view's props after handleNodeRemovals drained the tag. With no animated views left the props GC interval has stopped and no further commit drains it, so the entry leaks. Clear the orphaned registry one UI frame after the last view unmounts, and switch the GC view counter to viewsMap.size (the old counter drifted negative for nested AnimatedComponents sharing a viewTag).

Author: MatiPl01

packages/react-native-reanimated/Common/cpp/reanimated/Fabric/updates/AnimatedPropsRegistry.cpp

@@ -87,4 +87,10 @@ void AnimatedPropsRegistry::removeTag(const Tag tag) {
   timestampMap_.erase(tag);
 }
 
+void AnimatedPropsRegistry::removeAll() {
+  react_native_assert(UpdatesRegistryManager::isLockedByCurrentThread());
+  updatesRegistry_.clear();
+  timestampMap_.clear();
+}
+
 } // namespace reanimated

packages/react-native-reanimated/Common/cpp/reanimated/Fabric/updates/AnimatedPropsRegistry.h

@@ -18,6 +18,10 @@ class AnimatedPropsRegistry : public UpdatesRegistry {
   /// Also removes updates older than `cleanupTimestamp` from the registry.
   jsi::Value getUpdatesOlderThanTimestamp(jsi::Runtime &rt, double timestamp, double cleanupTimestamp);
 
+  /// Drops every entry. Called by the JS-side GC once the last animated view
+  /// unmounts, when every remaining entry is an orphan no other sweep collects.
+  void removeAll();
+
  private:
   std::unordered_map<Tag, double> timestampMap_;
 

packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/ReanimatedModuleProxy.cpp

@@ -663,6 +663,11 @@ jsi::Value ReanimatedModuleProxy::getSettledUpdates(jsi::Runtime &rt) {
       rt, currentTimestamp - 1000 /* 1 second */, currentTimestamp - 2000 /* 2 seconds */);
 }
 
+void ReanimatedModuleProxy::removeOrphanedProps(jsi::Runtime &rt) {
+  auto lock = updatesRegistryManager_->lock();
+  animatedPropsRegistry_->removeAll();
+}
+
 bool ReanimatedModuleProxy::handleEvent(
     const std::string &eventName,
     const int emitterReactTag,
@@ -1579,6 +1584,14 @@ jsi::Object ReanimatedModuleProxy::toOptimizedObject(jsi::Runtime &rt) {
     return strongThis->getSettledUpdates(rt);
   });
 
+  addMethod<0>(rt, obj, "removeOrphanedProps", [weakThis = weak_from_this()](jsi::Runtime &rt, const jsi::Value &) {
+    auto strongThis = weakThis.lock();
+    if (!strongThis) {
+      return;
+    }
+    strongThis->removeOrphanedProps(rt);
+  });
+
   addMethod<2>(
       rt,
       obj,

packages/react-native-reanimated/Common/cpp/reanimated/NativeModules/ReanimatedModuleProxy.h

@@ -149,6 +149,8 @@ class ReanimatedModuleProxy : public std::enable_shared_from_this<ReanimatedModu
 
   jsi::Value getSettledUpdates(jsi::Runtime &rt);
 
+  void removeOrphanedProps(jsi::Runtime &rt);
+
   void dispatchCommand(
       jsi::Runtime &rt,
       const jsi::Value &shadowNodeValue,

packages/react-native-reanimated/src/PropsRegistryGarbageCollector.ts

@@ -1,5 +1,7 @@
 'use strict';
 
+import { scheduleOnRN, scheduleOnUI } from 'react-native-worklets';
+
 import {
   unprocessColor,
   unprocessColorsInProps,
@@ -11,7 +13,6 @@ import { ReanimatedModule } from './ReanimatedModule';
 const FLUSH_INTERVAL_MS = 500;
 
 export const PropsRegistryGarbageCollector = {
-  viewsCount: 0,
   viewsMap: new Map<number, IAnimatedComponentInternal>(),
   intervalId: null as NodeJS.Timeout | null,
 
@@ -25,17 +26,20 @@ export const PropsRegistryGarbageCollector = {
       return;
     }
     this.viewsMap.set(viewTag, component);
-    this.viewsCount++;
-    if (this.viewsCount === 1) {
+    if (this.viewsMap.size === 1) {
       this.registerInterval();
     }
   },
 
   unregisterView(viewTag: number) {
-    this.viewsMap.delete(viewTag);
-    this.viewsCount--;
-    if (this.viewsCount === 0) {
+    // `delete` returns false when the tag wasn't tracked (the nested-component
+    // case registerView skipped above); bail to keep the count symmetric.
+    if (!this.viewsMap.delete(viewTag)) {
+      return;
+    }
+    if (this.viewsMap.size === 0) {
       this.unregisterInterval();
+      scheduleOrphanedPropsCleanup();
     }
   },
 
@@ -66,6 +70,25 @@ export const PropsRegistryGarbageCollector = {
   },
 };
 
+// The last animated view just unmounted, so the GC interval has stopped and no
+// commit will drain the registry. An in-flight animation frame can still re-add
+// the view's props; wait one UI frame for it to run, then clear the registry.
+function scheduleOrphanedPropsCleanup() {
+  scheduleOnUI(() => {
+    'worklet';
+    requestAnimationFrame(() => {
+      'worklet';
+      scheduleOnRN(removeOrphanedProps);
+    });
+  });
+}
+
+function removeOrphanedProps() {
+  if (PropsRegistryGarbageCollector.viewsMap.size === 0) {
+    ReanimatedModule.removeOrphanedProps();
+  }
+}
+
 function unprocessProps(props: StyleProps) {
   unprocessColorsInProps(props);
   unprocessBoxShadow(props);

packages/react-native-reanimated/src/ReanimatedModule/NativeReanimated.ts

@@ -244,6 +244,10 @@ See https://docs.swmansion.com/react-native-reanimated/docs/guides/troubleshooti
     return this.#reanimatedModuleProxy.getSettledUpdates();
   }
 
+  removeOrphanedProps() {
+    this.#reanimatedModuleProxy.removeOrphanedProps();
+  }
+
   registerPseudoStyles(
     shadowNodeWrapper: ShadowNodeWrapper,
     config: CSSPseudoStyleConfig
@@ -297,6 +301,8 @@ class DummyReanimatedModuleProxy implements ReanimatedModuleProxy {
     return [];
   }
 
+  removeOrphanedProps(): void {}
+
   registerPseudoStyles(): void {}
   unregisterPseudoStyles(): void {}
 }

packages/react-native-reanimated/src/ReanimatedModule/js-reanimated/JSReanimated.ts

@@ -349,6 +349,12 @@ class JSReanimated implements IReanimatedModule {
     );
   }
 
+  removeOrphanedProps(): void {
+    throw new Error(
+      '[Reanimated] `removeOrphanedProps` is not available in JSReanimated.'
+    );
+  }
+
   registerPseudoStyles(): void {
     throw new Error(
       '[Reanimated] `registerPseudoStyles` is not available in JSReanimated.'

packages/react-native-reanimated/src/ReanimatedModule/reanimatedModuleProxy.ts

@@ -94,6 +94,8 @@ export interface ReanimatedModuleProxy {
 
   getSettledUpdates(): SettledUpdate[];
 
+  removeOrphanedProps(): void;
+
   registerPseudoStyles(
     shadowNodeWrapper: ShadowNodeWrapper,
     config: CSSPseudoStyleConfig