From 14edd5d634b7773f366ebcf4e0311b013858a691 Mon Sep 17 00:00:00 2001
From: Samuel Susla <samuelsusla@fb.com>
Date: Wed, 31 Jul 2019 10:01:42 -0700
Subject: [PATCH] Break retain cycle in RCTScrollViewComponentView

Summary: Breaks cycle by making self weak and storing delegates weakly.

Reviewed By: fkgozali

Differential Revision: D16579754

fbshipit-source-id: 17174b0e91898a14a86b8b44677090be3044382d
---
 .../ComponentViews/ScrollView/RCTScrollViewComponentView.mm | 3 ++-
 React/Fabric/Utils/RNGenericDelegateSplitter.mm             | 6 +++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm b/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm
index d0297c694d3..3789b003efe 100644
--- a/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm
+++ b/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm
@@ -53,8 +53,9 @@ using namespace facebook::react;
     _containerView = [[UIView alloc] initWithFrame:CGRectZero];
     [_scrollView addSubview:_containerView];
 
+    __weak __typeof(self) weakSelf = self;
     _scrollViewDelegateSplitter = [[RNGenericDelegateSplitter alloc] initWithDelegateUpdateBlock:^(id delegate) {
-      self->_scrollView.delegate = delegate;
+      weakSelf.scrollView.delegate = delegate;
     }];
 
     [_scrollViewDelegateSplitter addDelegate:self];
diff --git a/React/Fabric/Utils/RNGenericDelegateSplitter.mm b/React/Fabric/Utils/RNGenericDelegateSplitter.mm
index 0add6b72b66..44b604838b3 100644
--- a/React/Fabric/Utils/RNGenericDelegateSplitter.mm
+++ b/React/Fabric/Utils/RNGenericDelegateSplitter.mm
@@ -8,7 +8,7 @@
 #import "RNGenericDelegateSplitter.h"
 
 @implementation RNGenericDelegateSplitter {
-  NSMutableArray *_delegates;
+  NSHashTable *_delegates;
 }
 
 #pragma mark - Public
@@ -17,7 +17,7 @@
 {
   if (self = [super init]) {
     _delegateUpdateBlock = block;
-    _delegates = [NSMutableArray new];
+    _delegates = [NSHashTable weakObjectsHashTable];
   }
 
   return self;
@@ -44,7 +44,7 @@
     return;
   }
 
-  _delegateUpdateBlock(_delegates.count == 1 ? _delegates.firstObject : self);
+  _delegateUpdateBlock(_delegates.count == 1 ? [_delegates allObjects].firstObject : self);
 }
 
 #pragma mark - Fast Forwarding