From 25e8fbe8ffa1c91522e91819a781434093f8b759 Mon Sep 17 00:00:00 2001
From: Joshua Gross <joshuagross@fb.com>
Date: Wed, 9 Jun 2021 23:46:45 -0700
Subject: [PATCH] Ensure that EventEmitterWrapper is cleaned up as soon as a
 View is deleted

Summary:
In T92179998, there is a crash when an EventEmitterWrapper is deallocated after the JS VM is torn down, and the EventEmitterWrapper tries to free its JSI::Pointer reference (double-free).

To make sure this happens less/not at all, free EventEmitterWrappers on ViewState when a view is deleted, instead of waiting for all of RN to be torn down.

Changelog: [Internal]

Reviewed By: fkgozali

Differential Revision: D29020768

fbshipit-source-id: 9d72a23bc9966992ef56c1e3ee523405d4333194
---
 .../react/fabric/mounting/SurfaceMountingManager.java     | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/SurfaceMountingManager.java b/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/SurfaceMountingManager.java
index 004af2f6471..650c5b91276 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/SurfaceMountingManager.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/SurfaceMountingManager.java
@@ -813,6 +813,14 @@ public class SurfaceMountingManager {
       viewState.mStateWrapper = null;
     }
 
+    // Destroy EventEmitterWrapper immediately instead of waiting for Java GC.
+    // Notably, this is also required to ensure that the EventEmitterWrapper is deallocated
+    // before the JS VM is deallocated, since it holds onto a JSI::Pointer.
+    if (viewState.mEventEmitter != null) {
+      viewState.mEventEmitter.destroy();
+      viewState.mEventEmitter = null;
+    }
+
     // For non-root views we notify viewmanager with {@link ViewManager#onDropInstance}
     ViewManager viewManager = viewState.mViewManager;
     if (!viewState.mIsRoot && viewManager != null) {