Introduce ReactHost.destroy() method to notifies when the React instance is destroyed (#47534)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/47534

This diff is introducing a new method to destroy React instance that allows the caller to be notified when the destroy finishes

This is necessary for apps to act upon destroy of the react instance

changelog: [internal] internal

Reviewed By: shwanton

Differential Revision: D65721107

fbshipit-source-id: 2d3d9755db38461ba381b86c72df5869c542379b

packages/react-native/ReactAndroid/api/ReactAndroid.api

@@ -205,6 +205,8 @@ public abstract interface class com/facebook/react/ReactHost {
 	public abstract fun addReactInstanceEventListener (Lcom/facebook/react/ReactInstanceEventListener;)V
 	public abstract fun createSurface (Landroid/content/Context;Ljava/lang/String;Landroid/os/Bundle;)Lcom/facebook/react/interfaces/fabric/ReactSurface;
 	public abstract fun destroy (Ljava/lang/String;Ljava/lang/Exception;)Lcom/facebook/react/interfaces/TaskInterface;
+	public abstract fun destroy (Ljava/lang/String;Ljava/lang/Exception;Lkotlin/jvm/functions/Function1;)Lcom/facebook/react/interfaces/TaskInterface;
+	public static synthetic fun destroy$default (Lcom/facebook/react/ReactHost;Ljava/lang/String;Ljava/lang/Exception;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)Lcom/facebook/react/interfaces/TaskInterface;
 	public abstract fun getCurrentReactContext ()Lcom/facebook/react/bridge/ReactContext;
 	public abstract fun getDevSupportManager ()Lcom/facebook/react/devsupport/interfaces/DevSupportManager;
 	public abstract fun getLifecycleState ()Lcom/facebook/react/common/LifecycleState;
@@ -3789,6 +3791,7 @@ public class com/facebook/react/runtime/ReactHostImpl : com/facebook/react/React
 	public fun addReactInstanceEventListener (Lcom/facebook/react/ReactInstanceEventListener;)V
 	public fun createSurface (Landroid/content/Context;Ljava/lang/String;Landroid/os/Bundle;)Lcom/facebook/react/interfaces/fabric/ReactSurface;
 	public fun destroy (Ljava/lang/String;Ljava/lang/Exception;)Lcom/facebook/react/interfaces/TaskInterface;
+	public fun destroy (Ljava/lang/String;Ljava/lang/Exception;Lkotlin/jvm/functions/Function1;)Lcom/facebook/react/interfaces/TaskInterface;
 	public fun getCurrentReactContext ()Lcom/facebook/react/bridge/ReactContext;
 	public fun getDevSupportManager ()Lcom/facebook/react/devsupport/interfaces/DevSupportManager;
 	public fun getLifecycleState ()Lcom/facebook/react/common/LifecycleState;

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactHost.kt

@@ -116,7 +116,26 @@ public interface ReactHost {
    *   be used to log properly the cause of destroy operation.
    * @return A task that completes when React Native gets destroyed.
    */
-  public fun destroy(reason: String, ex: Exception?): TaskInterface<Void>
+  public fun destroy(
+      reason: String,
+      ex: Exception?,
+  ): TaskInterface<Void>
+
+  /**
+   * Entrypoint to destroy the ReactInstance. If the ReactInstance is reloading, will wait until
+   * reload is finished, before destroying.
+   *
+   * @param reason describing why ReactHost is being destroyed (e.g. memmory pressure)
+   * @param ex exception that caused the trigger to destroy ReactHost (or null) This exception will
+   *   be used to log properly the cause of destroy operation.
+   * @param onDestroyFinished callback that will be called when React Native gets destroyed.
+   * @return A task that completes when React Native gets destroyed.
+   */
+  public fun destroy(
+      reason: String,
+      ex: Exception?,
+      onDestroyFinished: (instanceDestroyedSuccessfully: Boolean) -> Unit = {}
+  ): TaskInterface<Void>
 
   /**
    * Permanently destroys the ReactHost, including the ReactInstance (if any). The application MUST

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactHostImpl.java

@@ -86,6 +86,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 import kotlin.Unit;
 import kotlin.jvm.functions.Function0;
+import kotlin.jvm.functions.Function1;
 
 /**
  * A ReactHost is an object that manages a single {@link ReactInstance}. A ReactHost can be
@@ -542,6 +543,25 @@ public class ReactHostImpl implements ReactHost {
     InspectorNetworkHelper.loadNetworkResource(url, listener);
   }
 
+  @NonNull
+  @Override
+  public TaskInterface<Void> destroy(
+      @NonNull String reason,
+      @Nullable Exception ex,
+      @NonNull Function1<? super Boolean, Unit> onDestroyFinished) {
+    Task<Void> task = (Task<Void>) destroy(reason, ex);
+    return task.continueWith(
+        new Continuation<Void, Void>() {
+          @Nullable
+          @Override
+          public Void then(@NonNull Task<Void> task) throws Exception {
+            boolean instanceDestroyedSuccessfully = task.isCompleted() && !task.isFaulted();
+            onDestroyFinished.invoke(instanceDestroyedSuccessfully);
+            return null;
+          }
+        });
+  }
+
   /**
    * Entrypoint to destroy the ReactInstance. If the ReactInstance is reloading, will wait until
    * reload is finished, before destroying.