From 81264d353b31418cc37461a86d2a9a3bcdadba3b Mon Sep 17 00:00:00 2001
From: Jeff Tung <100387939+jtung-apple@users.noreply.github.com>
Date: Wed, 19 Feb 2025 08:48:15 -0800
Subject: [PATCH] [Darwin] MTRDevice _delegateExists cannot be called without
 holding lock

---
 src/darwin/Framework/CHIP/MTRDevice.mm               | 6 ++++++
 src/darwin/Framework/CHIP/MTRDeviceController_XPC.mm | 2 +-
 src/darwin/Framework/CHIP/MTRDevice_Internal.h       | 4 ++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/darwin/Framework/CHIP/MTRDevice.mm b/src/darwin/Framework/CHIP/MTRDevice.mm
index 7633d03ebd2d3b..1d09453c321d21 100644
--- a/src/darwin/Framework/CHIP/MTRDevice.mm
+++ b/src/darwin/Framework/CHIP/MTRDevice.mm
@@ -253,6 +253,12 @@ - (void)invalidate
     [self _cancelAllAttributeValueWaiters];
 }
 
+- (BOOL)delegateExists
+{
+    std::lock_guard lock(_lock);
+    return [self _delegateExists];
+}
+
 - (BOOL)_delegateExists
 {
     os_unfair_lock_assert_owner(&self->_lock);
diff --git a/src/darwin/Framework/CHIP/MTRDeviceController_XPC.mm b/src/darwin/Framework/CHIP/MTRDeviceController_XPC.mm
index 4871b1b129b699..97f447f1f81ac0 100644
--- a/src/darwin/Framework/CHIP/MTRDeviceController_XPC.mm
+++ b/src/darwin/Framework/CHIP/MTRDeviceController_XPC.mm
@@ -79,7 +79,7 @@ - (void)_updateRegistrationInfo
 
     for (NSNumber * nodeID in [self.nodeIDToDeviceMap keyEnumerator]) {
         MTRDevice * device = [self _deviceForNodeID:nodeID createIfNeeded:NO];
-        if ([device _delegateExists]) {
+        if ([device delegateExists]) {
             NSMutableDictionary * nodeDictionary = [NSMutableDictionary dictionary];
             MTR_REQUIRED_ATTRIBUTE(MTRDeviceControllerRegistrationNodeIDKey, nodeID, nodeDictionary)
 
diff --git a/src/darwin/Framework/CHIP/MTRDevice_Internal.h b/src/darwin/Framework/CHIP/MTRDevice_Internal.h
index 1887ddc3cb27b6..c7c4191b71b0d9 100644
--- a/src/darwin/Framework/CHIP/MTRDevice_Internal.h
+++ b/src/darwin/Framework/CHIP/MTRDevice_Internal.h
@@ -146,8 +146,12 @@ MTR_DIRECT_MEMBERS
 // Returns YES if any non-null delegates were found
 - (BOOL)_iterateDelegatesWithBlock:(void(NS_NOESCAPE ^ _Nullable)(MTRDeviceDelegateInfo * delegateInfo))block;
 
+// For subclasses to call while holding lock
 - (BOOL)_delegateExists;
 
+// For device controller or other objects to call
+- (BOOL)delegateExists;
+
 // Must be called by subclasses or MTRDevice implementation only.
 - (void)_delegateAdded:(id<MTRDeviceDelegate>)delegate;
 - (void)_delegateRemoved:(id<MTRDeviceDelegate>)delegate;