Force execution of all pre-allocation of views before execution of mount items

Summary:
Now that pre-allocation of views update props, we can just force the execution of "pre-allocation" instead of "create" mount item.

This should reduce the amount of mountItems that are created during commit phase.
This should improve TTI (I'm running a MobileLab)

Reviewed By: shergin

Differential Revision: D14297476

fbshipit-source-id: 3ade662848ed836dc3221abe78611bb4a2b94e00

ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java

@@ -193,7 +193,7 @@ public class FabricUIManager implements UIManager, LifecycleEventListener {
   }
 
   @DoNotStrip
-  private void preallocateView(int rootTag, int reactTag, final String componentName, ReadableMap props) {
+  private void preallocateView(int rootTag, int reactTag, final String componentName, ReadableMap props, boolean isLayoutable) {
     if (UiThreadUtil.isOnUiThread()) {
       // There is no reason to allocate views ahead of time on the main thread.
       return;
@@ -202,7 +202,7 @@ public class FabricUIManager implements UIManager, LifecycleEventListener {
     ThemedReactContext context = mReactContextForRootTag.get(rootTag);
     String component = sComponentNames.get(componentName);
     synchronized (mPreMountItemsLock) {
-      mPreMountItems.add(new PreAllocateViewMountItem(context, rootTag, reactTag, component, props));
+      mPreMountItems.add(new PreAllocateViewMountItem(context, rootTag, reactTag, component, props, isLayoutable));
     }
   }
 
@@ -313,6 +313,7 @@ public class FabricUIManager implements UIManager, LifecycleEventListener {
   @UiThread
   private void dispatchMountItems() {
     mRunStartTime = SystemClock.uptimeMillis();
+
     List<MountItem> mountItemsToDispatch;
     synchronized (mMountItemsLock) {
       if (mMountItems.isEmpty()) {
@@ -322,6 +323,21 @@ public class FabricUIManager implements UIManager, LifecycleEventListener {
       mMountItems = new ArrayList<>();
     }
 
+
+    // If there are MountItems to dispatch, we make sure all the "pre mount items" are executed
+    ArrayDeque<MountItem> mPreMountItemsToDispatch = null;
+    synchronized (mPreMountItemsLock) {
+      if (!mPreMountItems.isEmpty()) {
+        mPreMountItemsToDispatch = mPreMountItems;
+        mPreMountItems = new ArrayDeque<>(PRE_MOUNT_ITEMS_INITIAL_SIZE_ARRAY);
+      }
+    }
+
+    while (mPreMountItemsToDispatch != null && !mPreMountItemsToDispatch.isEmpty()) {
+      mPreMountItemsToDispatch.pollFirst().execute(mMountingManager);
+    }
+
+
     Systrace.beginSection(
         Systrace.TRACE_TAG_REACT_JAVA_BRIDGE,
         "FabricUIManager::mountViews (" + mountItemsToDispatch.size() + " batches)");

ReactAndroid/src/main/java/com/facebook/react/fabric/jsi/jni/Binding.cpp

@@ -166,34 +166,6 @@ local_ref<JString> getPlatformComponentName(const ShadowView& shadowView) {
   return componentName;
 }
 
-local_ref<JMountItem::javaobject> createCreateMountItem(
-    const jni::global_ref<jobject>& javaUIManager,
-    const ShadowViewMutation& mutation,
-    const Tag rootTag) {
-  static auto createJavaInstruction =
-      jni::findClassStatic(UIManagerJavaDescriptor)
-          ->getMethod<alias_ref<JMountItem>(jstring, jint, jint, jboolean, ReadableMap::javaobject)>(
-              "createMountItem");
-
-  auto newChildShadowView = mutation.newChildShadowView;
-
-  local_ref<JString> componentName =
-      getPlatformComponentName(newChildShadowView);
-
-  jboolean isVirtual = newChildShadowView.layoutMetrics == EmptyLayoutMetrics;
-
-  local_ref<ReadableMap::javaobject> props = isVirtual ? nullptr :
-        castReadableMap(ReadableNativeMap::newObjectCxxArgs(newChildShadowView.props->rawProps));
-
-  return createJavaInstruction(
-      javaUIManager,
-      componentName.get(),
-      rootTag,
-      newChildShadowView.tag,
-      isVirtual,
-      props != nullptr ? props.get() : nullptr);
-}
-
 local_ref<JMountItem::javaobject> createUpdateEventEmitterMountItem(
     const jni::global_ref<jobject>& javaUIManager,
     const ShadowViewMutation& mutation) {
@@ -353,11 +325,6 @@ void Binding::schedulerDidFinishTransaction(
         oldChildShadowView.layoutMetrics == EmptyLayoutMetrics;
 
     switch (mutation.type) {
-      case ShadowViewMutation::Create: {
-        mountItems[position++] =
-            createCreateMountItem(javaUIManager_, mutation, rootTag);
-        break;
-      }
       case ShadowViewMutation::Remove: {
         if (!isVirtual) {
           mountItems[position++] =
@@ -470,16 +437,14 @@ void Binding::schedulerDidRequestPreliminaryViewAllocation(
 
   bool isLayoutableShadowNode = shadowView.layoutMetrics != EmptyLayoutMetrics;
 
-  if (isLayoutableShadowNode) {
-    static auto preallocateView =
-        jni::findClassStatic(UIManagerJavaDescriptor)
-            ->getMethod<void(jint, jint, jstring, ReadableMap::javaobject)>("preallocateView");
+  static auto preallocateView =
+      jni::findClassStatic(UIManagerJavaDescriptor)
+          ->getMethod<void(jint, jint, jstring, ReadableMap::javaobject, jboolean)>("preallocateView");
 
-    local_ref<ReadableMap::javaobject> readableMap =
-        castReadableMap(ReadableNativeMap::newObjectCxxArgs(shadowView.props->rawProps));
-    preallocateView(
-        javaUIManager_, surfaceId, shadowView.tag, make_jstring(shadowView.componentName).get(), readableMap.get());
-  }
+  local_ref<ReadableMap::javaobject> readableMap =
+      castReadableMap(ReadableNativeMap::newObjectCxxArgs(shadowView.props->rawProps));
+  preallocateView(
+      javaUIManager_, surfaceId, shadowView.tag, make_jstring(shadowView.componentName).get(), readableMap.get(), isLayoutableShadowNode);
 }
 
 void Binding::registerNatives() {

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

@@ -168,15 +168,11 @@ public class MountingManager {
       ThemedReactContext themedReactContext,
       String componentName,
       int reactTag,
-
-      boolean isVirtual) {
+      boolean isLayoutable) {
     View view = null;
     ViewManager viewManager = null;
 
-    // This can be possible if the view was already pre-allocated
-    if (mTagToViewState.get(reactTag) != null) return;
-
-    if (!isVirtual) {
+    if (isLayoutable) {
       viewManager = mViewManagerRegistry.get(componentName);
       view = mViewPool.getOrCreateView(componentName, themedReactContext);
       view.setId(reactTag);
@@ -279,12 +275,15 @@ public class MountingManager {
     ThemedReactContext reactContext,
     String componentName,
     int reactTag,
-    ReadableMap props) {
+    ReadableMap props,
+    boolean isLayoutable) {
 
     if (mTagToViewState.get(reactTag) != null) return;
 
-    createView(reactContext, componentName, reactTag, false);
-    updateProps(reactTag, props);
+    createView(reactContext, componentName, reactTag, isLayoutable);
+    if (isLayoutable) {
+      updateProps(reactTag, props);
+    }
   }
 
   @UiThread

ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/mountitems/PreAllocateViewMountItem.java

@@ -18,19 +18,21 @@ public class PreAllocateViewMountItem implements MountItem {
   private final int mReactTag;
   private final ReadableMap mProps;
   private final ThemedReactContext mContext;
+  private final boolean mIsLayoutable;
 
   public PreAllocateViewMountItem(
-      ThemedReactContext context, int rootTag, int reactTag, String component, ReadableMap props) {
+      ThemedReactContext context, int rootTag, int reactTag, String component, ReadableMap props, boolean isLayoutable) {
     mContext = context;
     mComponent = component;
     mRootTag = rootTag;
     mProps = props;
     mReactTag = reactTag;
+    mIsLayoutable = isLayoutable;
   }
 
   @Override
   public void execute(MountingManager mountingManager) {
-    mountingManager.preallocateView(mContext, mComponent, mReactTag, mProps);
+    mountingManager.preallocateView(mContext, mComponent, mReactTag, mProps, mIsLayoutable);
   }
 
   @Override