Queue mount items executed before root view is attached

Summary:
Changelog: [Internal]

After D27016919, some mounting instructions can be executed before the view is attached, which is invalid. This change adds additional queue for such items, which can be later dispatched after view is ready.

The new queue is expected to be empty for usual rendering and used in prerendering flows only. In case of prerendering, it should only hold intermediate items between early start of `SurfaceHandler` and view attach.

Reviewed By: mdvacca

Differential Revision: D27291706

fbshipit-source-id: f383c1d0d7050f271993553b51bf2e387efe1e9e

Author: Andrei Shikov

ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/MountItemDispatcher.java

@@ -183,7 +183,7 @@ private boolean dispatchMountItems() {
           printMountItem(command, "dispatchMountItems: Executing viewCommandMountItem");
         }
         try {
-          command.execute(mMountingManager);
+          executeOrEnqueue(command);
         } catch (RetryableMountingLayerException e) {
           // If the exception is marked as Retryable, we retry the viewcommand exactly once, after
           // the current batch of mount items has finished executing.
@@ -225,7 +225,7 @@ private boolean dispatchMountItems() {
               + preMountItemsToDispatch.size());
 
       for (PreAllocateViewMountItem preMountItem : preMountItemsToDispatch) {
-        preMountItem.execute(mMountingManager);
+        executeOrEnqueue(preMountItem);
       }
 
       Systrace.endSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE);
@@ -244,7 +244,7 @@ private boolean dispatchMountItems() {
         }
 
         try {
-          mountItem.execute(mMountingManager);
+          executeOrEnqueue(mountItem);
         } catch (Throwable e) {
           // If there's an exception, we want to log diagnostics in prod and rethrow.
           FLog.e(TAG, "dispatchMountItems: caught exception, displaying all MountItems", e);
@@ -288,7 +288,7 @@ public void dispatchPreMountItems(long frameTimeNanos) {
           break;
         }
 
-        preMountItemToDispatch.execute(mMountingManager);
+        executeOrEnqueue(preMountItemToDispatch);
       }
     } finally {
       mInDispatch = false;
@@ -297,6 +297,16 @@ public void dispatchPreMountItems(long frameTimeNanos) {
     Systrace.endSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE);
   }
 
+  private void executeOrEnqueue(MountItem item) {
+    if (mMountingManager.isWaitingForViewAttach(item.getSurfaceId())) {
+      SurfaceMountingManager surfaceMountingManager =
+          mMountingManager.getSurfaceManager(item.getSurfaceId());
+      surfaceMountingManager.executeOnViewAttach(item);
+    } else {
+      item.execute(mMountingManager);
+    }
+  }
+
   @Nullable
   private static <E extends MountItem> List<E> drainConcurrentItemQueue(
       ConcurrentLinkedQueue<E> queue) {

ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/MountingManager.java

@@ -26,7 +26,6 @@
 import com.facebook.react.common.mapbuffer.ReadableMapBuffer;
 import com.facebook.react.fabric.FabricUIManager;
 import com.facebook.react.fabric.events.EventEmitterWrapper;
-import com.facebook.react.fabric.mounting.mountitems.MountItem;
 import com.facebook.react.touch.JSResponderHandler;
 import com.facebook.react.uimanager.RootViewManager;
 import com.facebook.react.uimanager.ThemedReactContext;
@@ -40,7 +39,7 @@
 
 /**
  * Class responsible for actually dispatching view updates enqueued via {@link
- * FabricUIManager#scheduleMountItems(int, MountItem[])} on the UI thread.
+ * FabricUIManager#scheduleMountItem} on the UI thread.
  */
 public class MountingManager {
   public static final String TAG = MountingManager.class.getSimpleName();
@@ -53,14 +52,12 @@ public class MountingManager {
   private final CopyOnWriteArrayList<Integer> mStoppedSurfaceIds = new CopyOnWriteArrayList<>();
 
   @Nullable private SurfaceMountingManager mMostRecentSurfaceMountingManager;
+  @Nullable private SurfaceMountingManager mLastQueriedSurfaceMountingManager;
 
   @NonNull private final JSResponderHandler mJSResponderHandler = new JSResponderHandler();
   @NonNull private final ViewManagerRegistry mViewManagerRegistry;
   @NonNull private final RootViewManager mRootViewManager = new RootViewManager();
 
-  private volatile int mStoppedSurfaceCacheLastId = View.NO_ID;
-  private volatile boolean mStoppedSurfaceCacheLastResult = false;
-
   public MountingManager(@NonNull ViewManagerRegistry viewManagerRegistry) {
     mViewManagerRegistry = viewManagerRegistry;
   }
@@ -81,7 +78,7 @@ public void startSurface(
   public SurfaceMountingManager startSurface(final int surfaceId) {
     SurfaceMountingManager surfaceMountingManager =
         new SurfaceMountingManager(
-            surfaceId, mJSResponderHandler, mViewManagerRegistry, mRootViewManager);
+            surfaceId, mJSResponderHandler, mViewManagerRegistry, mRootViewManager, this);
 
     // There could technically be a race condition here if addRootView is called twice from
     // different threads, though this is (probably) extremely unlikely, and likely an error.
@@ -117,8 +114,6 @@ public void attachRootView(
 
   @AnyThread
   public void stopSurface(final int surfaceId) {
-    mStoppedSurfaceCacheLastId = View.NO_ID;
-
     SurfaceMountingManager surfaceMountingManager = mSurfaceIdToManager.get(surfaceId);
     if (surfaceMountingManager != null) {
       // Maximum number of stopped surfaces to keep track of
@@ -145,6 +140,15 @@ public void stopSurface(final int surfaceId) {
 
   @Nullable
   public SurfaceMountingManager getSurfaceManager(int surfaceId) {
+    if (mLastQueriedSurfaceMountingManager != null
+        && mLastQueriedSurfaceMountingManager.getSurfaceId() == surfaceId) {
+      return mLastQueriedSurfaceMountingManager;
+    }
+
+    if (mMostRecentSurfaceMountingManager != null
+        && mMostRecentSurfaceMountingManager.getSurfaceId() == surfaceId) {
+      return mMostRecentSurfaceMountingManager;
+    }
     return mSurfaceIdToManager.get(surfaceId);
   }
 
@@ -164,32 +168,31 @@ public SurfaceMountingManager getSurfaceManagerEnforced(int surfaceId, String co
   }
 
   public boolean surfaceIsStopped(int surfaceId) {
-    if (surfaceId == View.NO_ID) {
-      return false;
-    }
-    if (surfaceId == mStoppedSurfaceCacheLastId) {
-      return mStoppedSurfaceCacheLastResult;
-    }
-
-    boolean res = surfaceIsStoppedImpl(surfaceId);
-    mStoppedSurfaceCacheLastResult = res;
-    mStoppedSurfaceCacheLastId = surfaceId;
-    return res;
-  }
-
-  private boolean surfaceIsStoppedImpl(int surfaceId) {
     if (mStoppedSurfaceIds.contains(surfaceId)) {
       return true;
     }
 
-    SurfaceMountingManager surfaceMountingManager = mSurfaceIdToManager.get(surfaceId);
+    SurfaceMountingManager surfaceMountingManager = getSurfaceManager(surfaceId);
     if (surfaceMountingManager != null && surfaceMountingManager.isStopped()) {
       return true;
     }
 
     return false;
   }
 
+  public boolean isWaitingForViewAttach(int surfaceId) {
+    SurfaceMountingManager mountingManager = getSurfaceManager(surfaceId);
+    if (mountingManager == null) {
+      return false;
+    }
+
+    if (mountingManager.isStopped()) {
+      return false;
+    }
+
+    return !mountingManager.isRootViewAttached();
+  }
+
   /**
    * Get SurfaceMountingManager associated with a ReactTag. Unfortunately, this requires lookups
    * over N maps, where N is the number of active or recently-stopped Surfaces. Each lookup will

ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/SurfaceMountingManager.java

@@ -26,6 +26,7 @@
 import com.facebook.react.bridge.UiThreadUtil;
 import com.facebook.react.common.build.ReactBuildConfig;
 import com.facebook.react.fabric.events.EventEmitterWrapper;
+import com.facebook.react.fabric.mounting.mountitems.MountItem;
 import com.facebook.react.touch.JSResponderHandler;
 import com.facebook.react.uimanager.IllegalViewOperationException;
 import com.facebook.react.uimanager.ReactRoot;
@@ -39,6 +40,7 @@
 import com.facebook.react.uimanager.ViewManagerRegistry;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentLinkedQueue;
 import javax.annotation.Nullable;
 
 public class SurfaceMountingManager {
@@ -47,15 +49,18 @@ public class SurfaceMountingManager {
   private static final boolean SHOW_CHANGED_VIEW_HIERARCHIES = ReactBuildConfig.DEBUG && false;
 
   private volatile boolean mIsStopped = false;
+  private volatile boolean mRootViewAttached = false;
 
   @Nullable private ThemedReactContext mThemedReactContext;
 
   // These are all non-null, until StopSurface is called
   private ConcurrentHashMap<Integer, ViewState> mTagToViewState =
       new ConcurrentHashMap<>(); // any thread
+  private ConcurrentLinkedQueue<MountItem> mOnViewAttachItems = new ConcurrentLinkedQueue<>();
   private JSResponderHandler mJSResponderHandler;
   private ViewManagerRegistry mViewManagerRegistry;
   private RootViewManager mRootViewManager;
+  private MountingManager mMountingManager;
 
   // This is null *until* StopSurface is called.
   private Set<Integer> mTagSetForStoppedSurface;
@@ -67,12 +72,14 @@ public SurfaceMountingManager(
       int surfaceId,
       @NonNull JSResponderHandler jsResponderHandler,
       @NonNull ViewManagerRegistry viewManagerRegistry,
-      @NonNull RootViewManager rootViewManager) {
+      @NonNull RootViewManager rootViewManager,
+      @NonNull MountingManager mountingManager) {
     mSurfaceId = surfaceId;
 
     mJSResponderHandler = jsResponderHandler;
     mViewManagerRegistry = viewManagerRegistry;
     mRootViewManager = rootViewManager;
+    mMountingManager = mountingManager;
   }
 
   public boolean isStopped() {
@@ -84,6 +91,14 @@ public void attachRootView(View rootView, ThemedReactContext themedReactContext)
     addRootView(rootView);
   }
 
+  public int getSurfaceId() {
+    return mSurfaceId;
+  }
+
+  public boolean isRootViewAttached() {
+    return mRootViewAttached;
+  }
+
   @Nullable
   public ThemedReactContext getContext() {
     return mThemedReactContext;
@@ -133,6 +148,11 @@ public boolean getViewExists(int tag) {
     return mTagToViewState.containsKey(tag);
   }
 
+  @AnyThread
+  public void executeOnViewAttach(MountItem item) {
+    mOnViewAttachItems.add(item);
+  }
+
   @AnyThread
   private void addRootView(@NonNull final View rootView) {
     if (isStopped()) {
@@ -174,6 +194,9 @@ public void run() {
             if (rootView instanceof ReactRoot) {
               ((ReactRoot) rootView).setRootViewTag(mSurfaceId);
             }
+            mRootViewAttached = true;
+
+            executeViewAttachMountItems();
           }
         };
 
@@ -184,6 +207,14 @@ public void run() {
     }
   }
 
+  @UiThread
+  private void executeViewAttachMountItems() {
+    while (!mOnViewAttachItems.isEmpty()) {
+      MountItem item = mOnViewAttachItems.poll();
+      item.execute(mMountingManager);
+    }
+  }
+
   /**
    * Stop surface and all operations within it. Garbage-collect Views (caller is responsible for
    * removing RootView from View layer).
@@ -232,6 +263,8 @@ public void run() {
             mTagToViewState = null;
             mJSResponderHandler = null;
             mRootViewManager = null;
+            mMountingManager = null;
+            mOnViewAttachItems.clear();
           }
         };