From 731bd95c430c752126aaaa34e4911ba2b87b382f Mon Sep 17 00:00:00 2001
From: Phillip Pan <phillippan@meta.com>
Date: Thu, 12 Sep 2024 22:57:11 -0700
Subject: [PATCH] do not iterate through moduleData array to handle UIManager
 batch completion (#46470)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/46470

Changelog: [iOS][Deprecated] - Deprecating RCTBridgeModule batchDidComplete and adding configuration to disable it

batchDidComplete is used for the UIManager to initiate a layout and mount after a callback has been initiated by the bridge. however, we iterate through the whole module array in order to get this single UIManager, which is unnecessary. this also increases risk of a crash because the module array is shared between threads.

Reviewed By: realsoelynn

Differential Revision: D62600034

fbshipit-source-id: 6c98df7d5ab282015181fb07764121693bcc141e
---
 packages/react-native/React/Base/RCTBridge.h  |  3 +++
 packages/react-native/React/Base/RCTBridge.mm | 11 +++++++++
 .../react-native/React/Base/RCTBridgeModule.h |  2 +-
 .../React/CxxBridge/RCTCxxBridge.mm           | 24 ++++++++++++++-----
 4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/packages/react-native/React/Base/RCTBridge.h b/packages/react-native/React/Base/RCTBridge.h
index 23937c18548..788730bba13 100644
--- a/packages/react-native/React/Base/RCTBridge.h
+++ b/packages/react-native/React/Base/RCTBridge.h
@@ -77,6 +77,9 @@ void RCTSetTurboModuleInteropBridgeProxyLogLevel(RCTBridgeProxyLoggingLevel logL
 BOOL RCTTurboModuleInteropForAllTurboModulesEnabled(void);
 void RCTEnableTurboModuleInteropForAllTurboModules(BOOL enabled);
 
+BOOL RCTBridgeModuleBatchDidCompleteDisabled(void);
+void RCTDisableBridgeModuleBatchDidComplete(BOOL disabled);
+
 typedef enum {
   kRCTGlobalScope,
   kRCTGlobalScopeUsingRetainJSCallback,
diff --git a/packages/react-native/React/Base/RCTBridge.mm b/packages/react-native/React/Base/RCTBridge.mm
index f576a6be6ac..9aaf79bd0b9 100644
--- a/packages/react-native/React/Base/RCTBridge.mm
+++ b/packages/react-native/React/Base/RCTBridge.mm
@@ -169,6 +169,17 @@ void RCTEnableTurboModuleSyncVoidMethods(BOOL enabled)
   gTurboModuleEnableSyncVoidMethods = enabled;
 }
 
+static BOOL gBridgeModuleDisableBatchDidComplete = NO;
+BOOL RCTBridgeModuleBatchDidCompleteDisabled(void)
+{
+  return gBridgeModuleDisableBatchDidComplete;
+}
+
+void RCTDisableBridgeModuleBatchDidComplete(BOOL disabled)
+{
+  gBridgeModuleDisableBatchDidComplete = disabled;
+}
+
 BOOL kDispatchAccessibilityManagerInitOntoMain = NO;
 BOOL RCTUIManagerDispatchAccessibilityManagerInitOntoMain(void)
 {
diff --git a/packages/react-native/React/Base/RCTBridgeModule.h b/packages/react-native/React/Base/RCTBridgeModule.h
index a77f7abd229..9595fa3d110 100644
--- a/packages/react-native/React/Base/RCTBridgeModule.h
+++ b/packages/react-native/React/Base/RCTBridgeModule.h
@@ -346,7 +346,7 @@ RCT_EXTERN_C_END
 /**
  * Notifies the module that a batch of JS method invocations has just completed.
  */
-- (void)batchDidComplete;
+- (void)batchDidComplete RCT_DEPRECATED;
 
 /**
  * Notifies the module that the active batch of JS method invocations has been
diff --git a/packages/react-native/React/CxxBridge/RCTCxxBridge.mm b/packages/react-native/React/CxxBridge/RCTCxxBridge.mm
index aeece2d3be0..cce793db1d2 100644
--- a/packages/react-native/React/CxxBridge/RCTCxxBridge.mm
+++ b/packages/react-native/React/CxxBridge/RCTCxxBridge.mm
@@ -1531,15 +1531,27 @@ RCT_NOT_IMPLEMENTED(-(instancetype)initWithBundleURL
 
 - (void)batchDidComplete
 {
-  // TODO #12592471: batchDidComplete is only used by RCTUIManager,
-  // can we eliminate this special case?
-  for (RCTModuleData *moduleData in _moduleDataByID) {
-    if (moduleData.implementsBatchDidComplete) {
+  if (RCTBridgeModuleBatchDidCompleteDisabled()) {
+    id uiManager = [self moduleForName:@"UIManager"];
+    if ([uiManager respondsToSelector:@selector(batchDidComplete)] &&
+        [uiManager respondsToSelector:@selector(methodQueue)]) {
       [self
           dispatchBlock:^{
-            [moduleData.instance batchDidComplete];
+            [uiManager batchDidComplete];
           }
-                  queue:moduleData.methodQueue];
+                  queue:[uiManager methodQueue]];
+    }
+  } else {
+    // TODO #12592471: batchDidComplete is only used by RCTUIManager,
+    // can we eliminate this special case?
+    for (RCTModuleData *moduleData in _moduleDataByID) {
+      if (moduleData.implementsBatchDidComplete) {
+        [self
+            dispatchBlock:^{
+              [moduleData.instance batchDidComplete];
+            }
+                    queue:moduleData.methodQueue];
+      }
     }
   }
 }