google · copybara-service · Mar 11, 2026 · Mar 11, 2026
diff --git a/connections/implementation/flags/nearby_connections_feature_flags.h b/connections/implementation/flags/nearby_connections_feature_flags.h
@@ -104,6 +104,10 @@ constexpr auto kMediumMaxAllowedReadBytes =
 // Disable/Enable refactor of BLE/L2CAP in Nearby Connections SDK.
 constexpr auto kRefactorBleL2cap =
     flags::Flag<bool>(kConfigPackage, "45737079", false);
+// Enable/Disable usage of shared CBPeripheralManager for GATT and L2CAP
+// servers.
+constexpr auto kEnableSharedPeripheralManager =
+    flags::Flag<bool>(kConfigPackage, "45770787", false);
 // Set the safe-to-disconnect version.
 // 0. Disabled all. 1. safe-to-disconnect 2. reserved 3. auto-reconnect
 // 4. auto-resume  5. non-distance-constraint-recovery 6. payload_ack

diff --git a/internal/platform/implementation/apple/Flags/GNCFeatureFlags.h b/internal/platform/implementation/apple/Flags/GNCFeatureFlags.h
@@ -29,4 +29,7 @@
 /** Checks whether BLE L2CAP refactor is enabled in the Nearby Connections SDK. */
 @property(nonatomic, class, readonly) BOOL refactorBleL2capEnabled;
 
+/** Checks whether shared peripheral manager is enabled in the Nearby Connections SDK. */
+@property(nonatomic, class, readonly) BOOL sharedPeripheralManagerEnabled;
+
 @end
diff --git a/internal/platform/implementation/apple/Flags/GNCFeatureFlags.mm b/internal/platform/implementation/apple/Flags/GNCFeatureFlags.mm
@@ -42,4 +42,10 @@ + (BOOL)refactorBleL2capEnabled {
           kRefactorBleL2cap);
 }
 
++ (BOOL)sharedPeripheralManagerEnabled {
+  return nearby::NearbyFlags::GetInstance().GetBoolFlag(
+      nearby::connections::config_package_nearby::nearby_connections_feature::
+          kEnableSharedPeripheralManager);
+}
+
 @end
diff --git a/internal/platform/implementation/apple/Flags/Tests/GNCFeatureFlagsTest.mm b/internal/platform/implementation/apple/Flags/Tests/GNCFeatureFlagsTest.mm
@@ -34,6 +34,13 @@ - (void)tearDown {
   nearby::NearbyFlags::GetInstance().OverrideBoolFlagValue(
       nearby::connections::config_package_nearby::nearby_connections_feature::kEnableBleL2cap,
       false);
+  nearby::NearbyFlags::GetInstance().OverrideBoolFlagValue(
+      nearby::connections::config_package_nearby::nearby_connections_feature::kRefactorBleL2cap,
+      false);
+  nearby::NearbyFlags::GetInstance().OverrideBoolFlagValue(
+      nearby::connections::config_package_nearby::nearby_connections_feature::
+          kEnableSharedPeripheralManager,
+      false);
 
   [super tearDown];
 }
@@ -78,4 +85,34 @@ - (void)testBleL2capEnabled_WhenFlagIsFalse {
   XCTAssertFalse([GNCFeatureFlags bleL2capEnabled]);
 }
 
+- (void)testRefactorBleL2capEnabled_WhenFlagIsTrue {
+  nearby::NearbyFlags::GetInstance().OverrideBoolFlagValue(
+      nearby::connections::config_package_nearby::nearby_connections_feature::kRefactorBleL2cap,
+      YES);
+  XCTAssertTrue([GNCFeatureFlags refactorBleL2capEnabled]);
+}
+
+- (void)testRefactorBleL2capEnabled_WhenFlagIsFalse {
+  nearby::NearbyFlags::GetInstance().OverrideBoolFlagValue(
+      nearby::connections::config_package_nearby::nearby_connections_feature::kRefactorBleL2cap,
+      NO);
+  XCTAssertFalse([GNCFeatureFlags refactorBleL2capEnabled]);
+}
+
+- (void)testSharedPeripheralManagerEnabled_WhenFlagIsTrue {
+  nearby::NearbyFlags::GetInstance().OverrideBoolFlagValue(
+      nearby::connections::config_package_nearby::nearby_connections_feature::
+          kEnableSharedPeripheralManager,
+      YES);
+  XCTAssertTrue([GNCFeatureFlags sharedPeripheralManagerEnabled]);
+}
+
+- (void)testSharedPeripheralManagerEnabled_WhenFlagIsFalse {
+  nearby::NearbyFlags::GetInstance().OverrideBoolFlagValue(
+      nearby::connections::config_package_nearby::nearby_connections_feature::
+          kEnableSharedPeripheralManager,
+      NO);
+  XCTAssertFalse([GNCFeatureFlags sharedPeripheralManagerEnabled]);
+}
+
 @end
diff --git a/internal/platform/implementation/apple/Mediums/BLE/GNCBLEGATTServer.h b/internal/platform/implementation/apple/Mediums/BLE/GNCBLEGATTServer.h
@@ -15,6 +15,8 @@
 #import <CoreBluetooth/CoreBluetooth.h>
 #import <Foundation/Foundation.h>
 
+#import "internal/platform/implementation/apple/Mediums/BLE/GNCPeripheralManager.h"
+
 @class GNCBLEGATTCharacteristic;
 
 NS_ASSUME_NONNULL_BEGIN
@@ -57,7 +59,18 @@ typedef void (^GNCStopAdvertisingCompletionHandler)(NSError *_Nullable error);
  *
  * @note The public APIs of this class are thread safe.
  */
-@interface GNCBLEGATTServer : NSObject
+@interface GNCBLEGATTServer : NSObject <GNCPeripheralManagerDelegate>
+
+/**
+ * Initializes the GATT server.
+ *
+ * @param peripheralManager The peripheral manager to use.
+ * @param queue The queue to use for delegate callbacks and internal operations.
+ */
+- (instancetype)initWithPeripheralManager:(nullable id<GNCPeripheralManager>)peripheralManager
+                                    queue:(nullable dispatch_queue_t)queue;
+
+- (instancetype)init NS_UNAVAILABLE;
 
 /**
  * Creates a characteristic and adds it to the GATT server.

diff --git a/internal/platform/implementation/apple/Mediums/BLE/GNCBLEGATTServer.m b/internal/platform/implementation/apple/Mediums/BLE/GNCBLEGATTServer.m
@@ -59,30 +59,33 @@ @implementation GNCBLEGATTServer {
   NSDictionary<NSString *, id> *_advertisementData;
 }
 
-- (instancetype)init {
+- (instancetype)initWithPeripheralManager:(nullable id<GNCPeripheralManager>)peripheralManager
+                                    queue:(nullable dispatch_queue_t)queue {
   self = [super init];
   if (self) {
-    _queue = dispatch_queue_create(kGNCBLEGATTServerQueueLabel, DISPATCH_QUEUE_SERIAL);
-    _peripheralManager = [[CBPeripheralManager alloc] initWithDelegate:nil queue:_queue];
-    // Set for @c GNCPeripheralManager to be able to forward callbacks.
-    _peripheralManager.peripheralDelegate = self;
-    _services = [[NSMutableDictionary alloc] init];
-    _pendingCharacteristics = [[NSMutableDictionary alloc] init];
-    _characteristicValues = [[NSMutableDictionary alloc] init];
-    _advertisementData = nil;
-  }
-  return self;
-}
+    _queue = queue ?: dispatch_queue_create(kGNCBLEGATTServerQueueLabel, DISPATCH_QUEUE_SERIAL);
+    if (GNCFeatureFlags.sharedPeripheralManagerEnabled) {
+      if (!peripheralManager) {
+        // In shared mode, the peripheral manager must be injected.
+        [NSException raise:NSInvalidArgumentException
+                    format:@"Peripheral manager cannot be nil when shared manager is enabled."];
+      }
+      _peripheralManager = peripheralManager;
+      // In shared mode, do NOT set the delegate. The Multiplexer handles callbacks.
+    } else {
+      // Legacy mode: Create a new manager if one isn't provided.
+      if (!peripheralManager) {
+        peripheralManager = [[CBPeripheralManager alloc]
+            initWithDelegate:self
+                       queue:_queue
+                     options:@{CBPeripheralManagerOptionShowPowerAlertKey : @NO}];
+      }
+      _peripheralManager = peripheralManager;
+      // In legacy mode, we own the manager (or use the injected one as if we own it) and set the
+      // delegate.
+      _peripheralManager.peripheralDelegate = self;
+    }
 
-// This is private and should only be used for tests. The provided peripheral manager must call
-// delegate methods on the main queue.
-- (instancetype)initWithPeripheralManager:(nullable id<GNCPeripheralManager>)peripheralManager {
-  self = [super init];
-  if (self) {
-    _queue = dispatch_get_main_queue();
-    _peripheralManager = peripheralManager;
-    // Set for @c GNCPeripheralManager to be able to forward callbacks.
-    _peripheralManager.peripheralDelegate = self;
     _services = [[NSMutableDictionary alloc] init];
     _pendingCharacteristics = [[NSMutableDictionary alloc] init];
     _characteristicValues = [[NSMutableDictionary alloc] init];
@@ -342,6 +345,12 @@ - (void)gnc_peripheralManager:(id<GNCPeripheralManager>)peripheral
 - (void)gnc_peripheralManager:(id<GNCPeripheralManager>)peripheral
         didReceiveReadRequest:(CBATTRequest *)request {
   dispatch_assert_queue(_queue);
+  if (!_services[request.characteristic.service.UUID]) {
+    // This server does not own the requested service. Ignore the request to allow other listeners
+    // (or future listeners) to handle it.
+    return;
+  }
+
   NSData *value =
       _characteristicValues[request.characteristic.service.UUID][request.characteristic.UUID];
   if (!value) {

diff --git a/internal/platform/implementation/apple/Mediums/BLE/GNCBLEL2CAPServer.h b/internal/platform/implementation/apple/Mediums/BLE/GNCBLEL2CAPServer.h
@@ -15,6 +15,8 @@
 #import <CoreBluetooth/CoreBluetooth.h>
 #import <Foundation/Foundation.h>
 
+#import "internal/platform/implementation/apple/Mediums/BLE/GNCPeripheralManager.h"
+
 @class GNCBLEL2CAPStream;
 @protocol GNCPeripheralManager;
 
@@ -42,7 +44,7 @@ typedef void (^GNCOpenL2CAPServerChannelOpendCompletionHandler)(GNCBLEL2CAPStrea
  *
  * @note The public APIs of this class are thread safe.
  */
-@interface GNCBLEL2CAPServer : NSObject
+@interface GNCBLEL2CAPServer : NSObject <GNCPeripheralManagerDelegate>
 
 // Represents a PSM (Protocol/Service Multiplexer) value for an L2CAP channel.
 @property(atomic, readonly) CBL2CAPPSM PSM;
@@ -57,6 +59,8 @@ typedef void (^GNCOpenL2CAPServerChannelOpendCompletionHandler)(GNCBLEL2CAPStrea
 - (instancetype)initWithPeripheralManager:(nullable id<GNCPeripheralManager>)peripheralManager
                                     queue:(nullable dispatch_queue_t)queue;
 
+- (instancetype)init NS_UNAVAILABLE;
+
 /**
  * Starts listening for an L2CAP channel.
  *

diff --git a/internal/platform/implementation/apple/Mediums/BLE/GNCBLEL2CAPServer.m b/internal/platform/implementation/apple/Mediums/BLE/GNCBLEL2CAPServer.m
@@ -17,6 +17,7 @@
 #import <CoreBluetooth/CoreBluetooth.h>
 #import <Foundation/Foundation.h>
 
+#import "internal/platform/implementation/apple/Flags/GNCFeatureFlags.h"
 #import "internal/platform/implementation/apple/Log/GNCLogger.h"
 #import "internal/platform/implementation/apple/Mediums/BLE/GNCBLEError.h"
 #import "internal/platform/implementation/apple/Mediums/BLE/GNCBLEL2CAPStream.h"
@@ -43,21 +44,25 @@ @implementation GNCBLEL2CAPServer {
   BOOL _alreadyStartedWhenPeripheralPoweredOff;
 }
 
-- (instancetype)init {
-  return [self initWithPeripheralManager:nil queue:nil];
-}
-
-// This is private and should only be used for tests. The provided peripheral manager must call
-// delegate methods on the main queue.
 - (instancetype)initWithPeripheralManager:(nullable id<GNCPeripheralManager>)peripheralManager
                                     queue:(nullable dispatch_queue_t)queue {
   self = [super init];
   if (self) {
     _queue = queue ?: dispatch_queue_create(kGNCBLEL2CAPServerQueueLabel, DISPATCH_QUEUE_SERIAL);
-    if (peripheralManager) {
+    if (GNCFeatureFlags.sharedPeripheralManagerEnabled) {
+      if (!peripheralManager) {
+        // In shared mode, the peripheral manager must be injected.
+        [NSException raise:NSInvalidArgumentException
+                    format:@"Peripheral manager cannot be nil when shared manager is enabled."];
+      }
       _peripheralManager = peripheralManager;
-      // Set for @c GNCPeripheralManager to be able to forward callbacks.
-      _peripheralManager.peripheralDelegate = self;
+      // In shared mode, do NOT set the delegate. The Multiplexer handles callbacks.
+    } else {
+      if (peripheralManager) {
+        _peripheralManager = peripheralManager;
+        // Set for @c GNCPeripheralManager to be able to forward callbacks.
+        _peripheralManager.peripheralDelegate = self;
+      }
     }
   }
   return self;
@@ -70,20 +75,36 @@ - (void)startListeningChannelWithPSMPublishedCompletionHandler:
                                         channelOpenedCompletionHandler {
   _psmPublishedCompletionHandler = [psmPublishedCompletionHandler copy];
   _channelOpenedCompletionHandler = [channelOpenedCompletionHandler copy];
-  if (!_queue) {
-    _psmPublishedCompletionHandler(0, [NSError errorWithDomain:GNCBLEErrorDomain
-                                                          code:GNCBLEErrorL2CAPListeningOnQueueNil
-                                                      userInfo:nil]);
-    return;
-  }
-  if (!_peripheralManager) {
-    // Lazy initialization to avoid system dialog on app startup before pairing.
-    _peripheralManager = [[CBPeripheralManager alloc] initWithDelegate:nil
-                                                                 queue:_queue
-                                                               options:nil];
-
-    // Set for @c GNCPeripheralManager to be able to forward callbacks.
-    _peripheralManager.peripheralDelegate = self;
+  if (GNCFeatureFlags.sharedPeripheralManagerEnabled) {
+    if (!_queue) {
+      if (_psmPublishedCompletionHandler) {
+        _psmPublishedCompletionHandler(0,
+                                       [NSError errorWithDomain:GNCBLEErrorDomain
+                                                           code:GNCBLEErrorL2CAPListeningOnQueueNil
+                                                       userInfo:nil]);
+      }
+      return;
+    }
+    if (!_peripheralManager) {
+      GNCLoggerError(@"[NEARBY] Peripheral manager must not be nil.");
+      return;
+    }
+  } else {
+    if (!_queue) {
+      _psmPublishedCompletionHandler(0, [NSError errorWithDomain:GNCBLEErrorDomain
+                                                            code:GNCBLEErrorL2CAPListeningOnQueueNil
+                                                        userInfo:nil]);
+      return;
+    }
+    if (!_peripheralManager) {
+      // Lazy initialization to avoid system dialog on app startup before pairing.
+      _peripheralManager = [[CBPeripheralManager alloc] initWithDelegate:nil
+                                                                   queue:_queue
+                                                                 options:nil];
+
+      // Set for @c GNCPeripheralManager to be able to forward callbacks.
+      _peripheralManager.peripheralDelegate = self;
+    }
   }
 
   if (_PSM > 0) {

diff --git a/internal/platform/implementation/apple/Mediums/BLE/GNCBLEMedium.m b/internal/platform/implementation/apple/Mediums/BLE/GNCBLEMedium.m
@@ -40,16 +40,6 @@
   return [NSError errorWithDomain:GNCBLEErrorDomain code:GNCBLEErrorAlreadyScanning userInfo:nil];
 }
 
-static GNCBLEL2CAPServer *_Nonnull CreateL2CapServer(
-    id<GNCPeripheralManager> _Nullable peripheralManager) {
-  if (!peripheralManager) {
-    return [[GNCBLEL2CAPServer alloc] init];
-  } else {
-    return [[GNCBLEL2CAPServer alloc] initWithPeripheralManager:peripheralManager
-                                                          queue:dispatch_get_main_queue()];
-  }
-}
-
 @interface GNCBLEMedium () <GNCCentralManagerDelegate, CBCentralManagerDelegate>
 @end
 
@@ -164,7 +154,16 @@ - (void)startAdvertisingData:(NSDictionary<CBUUID *, NSData *> *)serviceData
            completionHandler:(nullable GNCStartAdvertisingCompletionHandler)completionHandler {
   dispatch_async(_queue, ^{
     if (!_server) {
-      _server = [[GNCBLEGATTServer alloc] init];
+      if (GNCFeatureFlags.sharedPeripheralManagerEnabled) {
+        // TODO (edwinwu): Implement shared peripheral manager.
+        // For now, raise an exception.
+        [NSException raise:NSInvalidArgumentException
+                    format:@"Not implemented for shared manager is enabled."];
+      } else {
+        // In legacy mode, we pass nil (or a separate manager) and do NOT add to multiplexer.
+        // GNCBLEGATTServer will create its own internal manager.
+        _server = [[GNCBLEGATTServer alloc] initWithPeripheralManager:nil queue:nil];
+      }
     }
     [_server startAdvertisingData:serviceData completionHandler:completionHandler];
   });
@@ -238,7 +237,14 @@ - (void)startGATTServerWithCompletionHandler:
     (nullable GNCGATTServerCompletionHandler)completionHandler {
   dispatch_async(_queue, ^{
     if (!_server) {
-      _server = [[GNCBLEGATTServer alloc] init];
+      if (GNCFeatureFlags.sharedPeripheralManagerEnabled) {
+        // TODO (edwinwu): Implement shared peripheral manager.
+        // For now, raise an exception.
+        [NSException raise:NSInvalidArgumentException
+                    format:@"Not implemented for shared manager is enabled."];
+      } else {
+        _server = [[GNCBLEGATTServer alloc] initWithPeripheralManager:nil queue:nil];
+      }
     }
     if (completionHandler) {
       completionHandler(_server, nil);
@@ -284,7 +290,17 @@ - (void)openL2CAPServerWithPSMPublishedCompletionHandler:
                                            (nullable id<GNCPeripheralManager>)peripheralManager {
   dispatch_async(_queue, ^{
     if (!_l2capServer) {
-      _l2capServer = CreateL2CapServer(peripheralManager);
+      if (GNCFeatureFlags.sharedPeripheralManagerEnabled) {
+        // TODO (edwinwu): Implement shared peripheral manager.
+        // For now, raise an exception.
+        [NSException raise:NSInvalidArgumentException
+                    format:@"Not implemented for shared manager is enabled."];
+      } else {
+        // Legacy mode
+        _l2capServer = [[GNCBLEL2CAPServer alloc]
+            initWithPeripheralManager:peripheralManager  // Likely nil, so Server creates new one
+                                queue:peripheralManager ? dispatch_get_main_queue() : nil];
+      }
     }
     [_l2capServer
         startListeningChannelWithPSMPublishedCompletionHandler:psmPublishedCompletionHandler

diff --git a/internal/platform/implementation/apple/Mediums/BLE/Tests/BUILD b/internal/platform/implementation/apple/Mediums/BLE/Tests/BUILD
@@ -26,11 +26,11 @@ objc_library(
     srcs = [
         "GNCBLEGATTCharacteristicTest.mm",
         "GNCBLEGATTClientTest.m",
-        "GNCBLEGATTServerTest.m",
+        "GNCBLEGATTServerTest.mm",
         "GNCBLEL2CAPClientTest.m",
         "GNCBLEL2CAPConnectionTest.m",
         "GNCBLEL2CAPFakeInputOutputStream.m",
-        "GNCBLEL2CAPServerTest.m",
+        "GNCBLEL2CAPServerTest.mm",
         "GNCBLEL2CAPStreamTest.m",
         "GNCBLEMediumTest.m",
         "GNCFakeBLEGATTServer.m",
@@ -67,6 +67,8 @@ objc_library(
         "GNCMFakeConnection.h",
     ],
     deps = [
+        "//connections/implementation/flags:connections_flags",
+        "//internal/flags:nearby_flags",
         "//internal/platform/implementation/apple",  # buildcleaner: keep
         "//internal/platform/implementation/apple/Mediums/BLE",
         "//internal/platform/implementation/apple/Mediums/BLE/Sockets:Shared",