Fixing darwin crashes, and XPC invalidation (project-chip#35056)

* Fixing crashes

* Restyled by clang-format

---------

Co-authored-by: Restyled.io <commits@restyled.io>

Author: woody-apple

src/darwin/Framework/CHIP/MTRDeviceController_XPC.mm

@@ -67,8 +67,16 @@ - (id)initWithUniqueIdentifier:(NSUUID *)UUID xpConnectionBlock:(NSXPCConnection
             self.xpcConnection.exportedInterface = [NSXPCInterface interfaceWithProtocol:@protocol(MTRXPCClientProtocol)];
             self.xpcConnection.exportedObject = self;
 
-            MTR_LOG("Resuming new XPC connection");
-            [self.xpcConnection resume];
+            self.xpcConnection.interruptionHandler = ^{
+                MTR_LOG_ERROR("XPC Connection for device controller interrupted: %@", UUID);
+            };
+
+            self.xpcConnection.invalidationHandler = ^{
+                MTR_LOG_ERROR("XPC Connection for device controller invalidated: %@", UUID);
+            };
+
+            MTR_LOG("Activating new XPC connection");
+            [self.xpcConnection activate];
         } else {
             MTR_LOG_ERROR("Failed to set up XPC Connection");
             return nil;

src/platform/Darwin/DnssdContexts.cpp

@@ -247,6 +247,7 @@ void MdnsContexts::Delete(GenericContext * context)
     if (context->serviceRef != nullptr)
     {
         DNSServiceRefDeallocate(context->serviceRef);
+        context->serviceRef = nullptr;
     }
     chip::Platform::Delete(context);
 }