Fixed deadlock during stop scanning on iOS

PiperOrigin-RevId: 791998760
2026-09-14 22:56:12 -04:00 · 2025-08-06 22:47:41 -07:00
parent 807bf7172f
commit ddd4f922b9
6 changed files with 88 additions and 35 deletions
@@ -1,7 +1,3 @@
-load("@rules_cc//cc:cc_library.bzl", "cc_library")
-load("@rules_cc//cc:cc_test.bzl", "cc_test")
-load("@rules_cc//cc:objc_library.bzl", "objc_library")
-
 # Copyright 2020 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -15,6 +11,11 @@ load("@rules_cc//cc:objc_library.bzl", "objc_library")
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+load("@rules_cc//cc:objc_library.bzl", "objc_library")
+
 licenses(["notice"])

 package(default_visibility = [
@@ -25,13 +26,35 @@ package(default_visibility = [
    "//sharing:__subpackages__",
 ])

+objc_library(
+    name = "comm",
+    srcs = [
+        "multi_thread_executor.mm",
+    ],
+    hdrs = [
+        "multi_thread_executor.h",
+        "scheduled_executor.h",
+        "single_thread_executor.h",
+    ],
+    deps = [
+        "//internal/platform:base",
+        "//internal/platform:cancellation_flag",
+        "//internal/platform:uuid",
+        "//internal/platform/implementation:comm",
+        "//internal/platform/implementation:types",
+        "//internal/platform/implementation/apple/Flags",
+        "//internal/platform/implementation/apple/Log:GNCLogger",
+        "//third_party/apple_frameworks:CoreBluetooth",
+        "//third_party/apple_frameworks:Foundation",
+    ],
+)
+
 objc_library(
    name = "apple",
    srcs = [
        "awdl.mm",
        "crypto.mm",
        "device_info.mm",
-        "multi_thread_executor.mm",
        "platform.mm",
        "preferences_manager.mm",
        "scheduled_executor.mm",
@@ -42,10 +65,7 @@ objc_library(
    hdrs = [
        "awdl.h",
        "device_info.h",
-        "multi_thread_executor.h",
        "preferences_manager.h",
-        "scheduled_executor.h",
-        "single_thread_executor.h",
        "timer.h",
        "wifi.h",
        "wifi_hotspot.h",
@@ -55,6 +75,7 @@ objc_library(
    aspect_hints = ["//tools/build_defs/swift:no_module"],
    features = ["-layering_check"],
    deps = [
+        ":comm",
        ":Platform_cc",
        ":Shared",
        ":ble_v2",
@@ -119,10 +140,12 @@ objc_library(
    # Prevent Objective-C++ headers from being pulled into swift.
    aspect_hints = ["//tools/build_defs/swift:no_module"],
    deps = [
+        ":comm",
        "//internal/platform:base",
        "//internal/platform:cancellation_flag",
        "//internal/platform:uuid",
        "//internal/platform/implementation:comm",
+        "//internal/platform/implementation:types",
        "//internal/platform/implementation/apple/Flags",
        "//internal/platform/implementation/apple/Log:GNCLogger",
        "//internal/platform/implementation/apple/Mediums",
@@ -17,7 +17,7 @@

 #import "internal/platform/implementation/apple/Mediums/BLEv2/GNCBLEL2CAPClient.h"
 #import "internal/platform/implementation/apple/Mediums/BLEv2/GNCBLEL2CAPServer.h"
-// #import "internal/platform/implementation/apple/Mediums/BLEv2/GNCBLEL2CAPStream.h"
+#import "internal/platform/implementation/apple/Mediums/BLEv2/GNCCentralManager.h"

@class GNCBLEGATTServer;
@class GNCBLEGATTClient;
@@ -101,6 +101,20 @@ typedef void (^GNCGATTConnectionCompletionHandler)(GNCBLEGATTClient *_Nullable c
 */
@interface GNCBLEMedium : NSObject

+/**
+ * Initializes the BLE medium.
+ */
+- (instancetype)init;
+
+/**
+ * Initializes the BLE medium with a custom central manager.
+ *
+ * @param centralManager The central manager to use for BLE operations.
+ * @param queue The queue to use for all internal operations.
+ */
+- (instancetype)initWithCentralManager:(id<GNCCentralManager>)centralManager
+                                 queue:(nullable dispatch_queue_t)queue;
+
 /** The hardware supports BOTH advertising extensions and extended scans. */
@property(nonatomic, readonly) BOOL supportsExtendedAdvertisements;

@@ -171,8 +185,7 @@ typedef void (^GNCGATTConnectionCompletionHandler)(GNCBLEGATTClient *_Nullable c
 * @param completionHandler Called on a private queue with @c nil if successfully resumed scanning
 *                          or an error if one has occurred.
 */
- (void)resumeMediumScanning:
-    (nullable GNCStartScanningCompletionHandler)completionHandler;
+- (void)resumeMediumScanning:(nullable GNCStartScanningCompletionHandler)completionHandler;

 /**
 * Starts a GATT server.
@@ -96,11 +96,11 @@ static GNCBLEL2CAPServer *_Nonnull CreateL2CapServer(
 }

 - (instancetype)init {
+  dispatch_queue_t queue = dispatch_queue_create(kBLEMediumQueueLabel, DISPATCH_QUEUE_SERIAL);
  CBCentralManager *centralManager =
      [[CBCentralManager alloc] initWithDelegate:self
-                                           queue:_queue
+                                           queue:queue
                                         options:@{CBCentralManagerOptionShowPowerAlertKey : @NO}];
-  dispatch_queue_t queue = dispatch_queue_create(kBLEMediumQueueLabel, DISPATCH_QUEUE_SERIAL);
  return [self initWithCentralManager:centralManager queue:queue];
 }

@@ -506,43 +506,33 @@ static GNCBLEL2CAPServer *_Nonnull CreateL2CapServer(
 #pragma mark - CBCentralManagerDelegate

 - (void)centralManagerDidUpdateState:(CBCentralManager *)central {
-  dispatch_async(_queue, ^{
-    [self gnc_centralManagerDidUpdateState:central];
-  });
+  [self gnc_centralManagerDidUpdateState:central];
 }

 - (void)centralManager:(CBCentralManager *)central
    didDiscoverPeripheral:(CBPeripheral *)peripheral
        advertisementData:(NSDictionary<NSString *, id> *)advertisementData
                     RSSI:(NSNumber *)RSSI {
-  dispatch_async(_queue, ^{
-    [self gnc_centralManager:central
-        didDiscoverPeripheral:peripheral
-            advertisementData:advertisementData
-                         RSSI:RSSI];
-  });
+  [self gnc_centralManager:central
+      didDiscoverPeripheral:peripheral
+          advertisementData:advertisementData
+                       RSSI:RSSI];
 }

 - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {
-  dispatch_async(_queue, ^{
-    [self gnc_centralManager:central didConnectPeripheral:peripheral];
-  });
+  [self gnc_centralManager:central didConnectPeripheral:peripheral];
 }

 - (void)centralManager:(CBCentralManager *)central
    didFailToConnectPeripheral:(CBPeripheral *)peripheral
                         error:(nullable NSError *)error {
-  dispatch_async(_queue, ^{
-    [self gnc_centralManager:central didFailToConnectPeripheral:peripheral error:error];
-  });
+  [self gnc_centralManager:central didFailToConnectPeripheral:peripheral error:error];
 }

 - (void)centralManager:(CBCentralManager *)central
    didDisconnectPeripheral:(CBPeripheral *)peripheral
                      error:(nullable NSError *)error {
-  dispatch_async(_queue, ^{
-    [self gnc_centralManager:central didDisconnectPeripheral:peripheral error:error];
-  });
+  [self gnc_centralManager:central didDisconnectPeripheral:peripheral error:error];
 }

@end
@@ -65,6 +65,7 @@ objc_library(
        "//internal/platform/implementation/apple",  # buildcleaner: keep
        "//internal/platform/implementation/apple:Shared",
        "//internal/platform/implementation/apple:ble_v2",
+        "//internal/platform/implementation/apple:comm",
        "//internal/platform/implementation/apple/Mediums",
        "//third_party/apple_frameworks:CommonCrypto",
        "//third_party/apple_frameworks:CoreBluetooth",
@@ -29,6 +29,7 @@
 #import "internal/platform/implementation/apple/ble_l2cap_server_socket.h"
 #import "internal/platform/implementation/apple/ble_server_socket.h"
 #import "internal/platform/implementation/apple/bluetooth_adapter_v2.h"
+#import "internal/platform/implementation/apple/single_thread_executor.h"
 #include "internal/platform/implementation/ble_v2.h"
 #include "internal/platform/implementation/bluetooth_adapter.h"
 #include "internal/platform/uuid.h"
@@ -202,6 +203,9 @@ class BleMedium : public api::ble_v2::BleMedium {
                                  NSDictionary<CBUUID *, NSData *> *service_data);
  NSDate *GetLastTimestampToCleanExpiredAdvertisementPackets();

+  // The executor for handling callbacks.
+  apple::SingleThreadExecutor callback_executor_;
+
  GNCBLEMedium *medium_;

  PeripheralsMap peripherals_;
@@ -200,7 +200,8 @@ std::unique_ptr<api::ble_v2::BleMedium::ScanningSession> BleMedium::StartScannin
  [medium_ startScanningForService:serviceUUID
      advertisementFoundHandler:^(id<GNCPeripheral> peripheral,
                                  NSDictionary<CBUUID *, NSData *> *serviceData) {
-        HandleAdvertisementFound(peripheral, serviceData);
+        callback_executor_.Execute(
+            [this, peripheral, serviceData] { HandleAdvertisementFound(peripheral, serviceData); });
      }
      completionHandler:^(NSError *error) {
        if (scanning_cb_.start_scanning_result) {
@@ -234,7 +235,8 @@ bool BleMedium::StartScanning(const Uuid &service_uuid, api::ble_v2::TxPowerLeve
  [medium_ startScanningForService:serviceUUID
      advertisementFoundHandler:^(id<GNCPeripheral> peripheral,
                                  NSDictionary<CBUUID *, NSData *> *serviceData) {
-        HandleAdvertisementFound(peripheral, serviceData);
+        callback_executor_.Execute(
+            [this, peripheral, serviceData] { HandleAdvertisementFound(peripheral, serviceData); });
      }
      completionHandler:^(NSError *error) {
        if (error != nil) {
@@ -276,7 +278,8 @@ bool BleMedium::StartMultipleServicesScanning(const std::vector<Uuid> &service_u
  [medium_ startScanningForMultipleServices:serviceUUIDs
      advertisementFoundHandler:^(id<GNCPeripheral> peripheral,
                                  NSDictionary<CBUUID *, NSData *> *serviceData) {
-        HandleAdvertisementFound(peripheral, serviceData);
+        callback_executor_.Execute(
+            [this, peripheral, serviceData] { HandleAdvertisementFound(peripheral, serviceData); });
      }
      completionHandler:^(NSError *error) {
        if (error != nil) {
@@ -349,7 +352,26 @@ std::unique_ptr<api::ble_v2::GattClient> BleMedium::ConnectToGattServer(
    return nullptr;
  }

-  __block api::ble_v2::ClientGattConnectionCallback blockCallback = std::move(callback);
+  api::ble_v2::ClientGattConnectionCallback thread_callback = {
+      .on_characteristic_changed_cb =
+          [this,
+           call_on_characteristic_changed_cb = std::move(callback.on_characteristic_changed_cb)](
+              absl::string_view characteristic_uuid) mutable {
+            callback_executor_.Execute([characteristic_uuid = std::string(characteristic_uuid),
+                                        call_on_characteristic_changed_cb = std::move(
+                                            call_on_characteristic_changed_cb)]() mutable {
+              call_on_characteristic_changed_cb(characteristic_uuid);
+            });
+          },
+      .disconnected_cb =
+          [this, call_disconnected_cb = std::move(callback.disconnected_cb)]() mutable {
+            callback_executor_.Execute(
+                [call_disconnected_cb = std::move(call_disconnected_cb)]() mutable {
+                  call_disconnected_cb();
+                });
+          }};
+
+  __block api::ble_v2::ClientGattConnectionCallback blockCallback = std::move(thread_callback);

  dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
  __block GNCBLEGATTClient *blockClient = nil;