From 44bb39af1fdb32b49dda00c8f27994aa4d309db6 Mon Sep 17 00:00:00 2001
From: Nick Cooke <nickcooke@google.com>
Date: Wed, 6 Nov 2024 15:31:33 -0500
Subject: [PATCH] [Config] Prefer NSLock over objc_sync_enter for synchronizing
 value types

---
 .../SwiftNew/UserDefaultsManager.swift            | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/FirebaseRemoteConfig/SwiftNew/UserDefaultsManager.swift b/FirebaseRemoteConfig/SwiftNew/UserDefaultsManager.swift
index 2cdab034051..f6b1d2e5030 100644
--- a/FirebaseRemoteConfig/SwiftNew/UserDefaultsManager.swift
+++ b/FirebaseRemoteConfig/SwiftNew/UserDefaultsManager.swift
@@ -73,6 +73,7 @@ public class UserDefaultsManager: NSObject {
     }
   }
 
+  private static let sharedInstanceMapLock = NSLock()
   private static var sharedInstanceMap: [String: UserDefaults] = [:]
 
   /// Returns the shared user defaults instance for the given bundle identifier.
@@ -81,14 +82,14 @@ public class UserDefaultsManager: NSObject {
   /// - Returns: The shared user defaults instance.
   @objc(sharedUserDefaultsForBundleIdentifier:)
   static func sharedUserDefaultsForBundleIdentifier(_ bundleIdentifier: String) -> UserDefaults {
-    objc_sync_enter(sharedInstanceMap)
-    defer { objc_sync_exit(sharedInstanceMap) }
-    if let instance = sharedInstanceMap[bundleIdentifier] {
-      return instance
+    sharedInstanceMapLock.withLock {
+      if let instance = sharedInstanceMap[bundleIdentifier] {
+        return instance
+      }
+      let userDefaults = UserDefaults(suiteName: userDefaultsSuiteName(for: bundleIdentifier))!
+      sharedInstanceMap[bundleIdentifier] = userDefaults
+      return userDefaults
     }
-    let userDefaults = UserDefaults(suiteName: userDefaultsSuiteName(for: bundleIdentifier))!
-    sharedInstanceMap[bundleIdentifier] = userDefaults
-    return userDefaults
   }
 
   /// Returns the user defaults suite name for the given bundle identifier.