Android蓝牙使能流程图(Android Bluetooth enable) -- java jni层
在介绍Android enable流程之前，我们首先来看下Android的流程图
以上图示是android8以上的，主要跟Android8之前的架构在于Bluetooth stack跟vendor层之间增加一层HIDL，主要是抽象硬件层的作用
OK，回归主题，我们来看下Android的enable流程，首先上一张架构图
另外声明下：我们做了一些列的蓝牙教程(包括视频)。我们会以连载的方式持续更新,内容如下：
本专栏文章我们会以连载的方式持续更新，本专栏计划更新内容如下：
第一篇:蓝牙综合介绍 ，主要介绍蓝牙的一些概念，产生背景，发展轨迹，市面蓝牙介绍，以及蓝牙开发板介绍。
第二篇:Transport层介绍,主要介绍蓝牙协议栈跟蓝牙芯片之前的硬件传输协议,比如基于UART的H4,H5,BCSP，基于USB的H2等
第三篇:传统蓝牙controller介绍，主要介绍传统蓝牙芯片的介绍，包括射频层（RF），基带层（baseband），链路管理层（LMP）等
第四篇:传统蓝牙host介绍，主要介绍传统蓝牙的协议栈，比如HCI,L2CAP,SDP,RFCOMM,HFP,SPP,HID,AVDTP,AVCTP,A2DP,AVRCP,OBEX,PBAP,MAP等等一系列的协议吧。
第五篇：低功耗蓝牙controller介绍，主要介绍低功耗蓝牙芯片，包括物理层（PHY），链路层（LL）
第六篇：低功耗蓝牙host介绍，低功耗蓝牙协议栈的介绍，包括HCI,L2CAP,ATT,GATT,SM等
第七篇：蓝牙芯片介绍，主要介绍一些蓝牙芯片的初始化流程，基于HCI vendor command的扩展
第八篇：附录，主要介绍以上常用名词的介绍以及一些特殊流程的介绍等。
另外，开发板如下所示，对于想学习蓝牙协议栈的最好人手一套。以便更好的学习蓝牙协议栈，相信我，学完这一套视频你将拥有修改任何协议栈的能力（比如Linux下的bluez，Android下的bluedroid）。
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蓝牙交流扣扣群：970324688
Github代码：GitHub - sj15712795029/bluetooth_stack: 这是一个开源的双模蓝牙协议栈(bluetooth.stack)(btstack),可以运行在STM32,Linux.，包含HCI,L2CAP,SDP,RFCOMM,HFP,SPP,A2DP,AVRCP,AVDTP,AVCTP,OBEX,PBAP等协议，后续会继续维护，以达到商用的目的
入手开发板：https://shop220811498.taobao.com/category-1542116976.htm?spm=a1z10.5-c-s.w4010-22329603913.7.39ca7dbe2EA0K3&search=y&catName=%C0%B6%D1%C0%BF%AA%B7%A2%B0%E5#bd
蓝牙学习目录：一篇文章足够你学习蓝牙技术，提供史上最全的蓝牙技术（传统蓝牙/低功耗蓝牙）文章总结，文档下载总结（2020/12/11更新）_Wireless_Link的博客-CSDN博客_蓝牙eir
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步骤1：开机会启动SystemServer类的main函数
在Android系统启动过程中，SystemServer是第一个被启动的进程。当Android设备被开机后，内核会创建一个名为init的进程，init进程会启动Zygote进程，Zygote进程会启动SystemServer进程。因此，SystemServer是整个Android系统启动的核心进程，它负责初始化并启动大部分系统服务和应用程序，是整个Android系统的主要启动入口。
具体来说，SystemServer主要完成以下几个任务：
-
启动和初始化系统服务：SystemServer会启动和初始化大部分系统服务，例如ActivityManagerService、WindowManagerService、PackageManagerService、PowerManagerService等等。这些服务会在启动过程中被创建并注册到系统服务中心，供其他应用程序和服务调用。
-
启动和初始化核心应用程序：SystemServer会启动和初始化Android系统中的核心应用程序，例如SystemUI、Settings等等。这些应用程序会在启动过程中被创建并运行，提供各种用户界面和功能。
-
加载和初始化系统属性：SystemServer会加载和初始化/system/build.prop文件中定义的系统属性，例如设备型号、厂商信息等等。这些属性可以在系统运行时被访问和修改。
-
启动Adb守护进程：SystemServer会启动Adb守护进程，使得开发者可以通过adb工具来访问设备。
总之，SystemServer是整个Android系统启动过程中的核心进程，负责启动和初始化大部分系统服务和应用程序，为整个系统的运行提供基础支持。SystemServer的启动时间通常在内核启动之后的几秒钟内，具体时间取决于设备的硬件性能和系统配置。
/**
* The main entry point from zygote.
*/
public static void main(String[] args) {new SystemServer().run();
}SystemServer().run();执行startOtherServices(t);
然后startOtherServices(t);执行如下代码，开启Bluetooth service类
private void startOtherServices(@NonNull TimingsTraceAndSlog t) {...if (mFactoryTestMode == FactoryTest.FACTORY_TEST_LOW_LEVEL) {Slog.i(TAG, "No Bluetooth Service (factory test)");} else if (!context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)) {Slog.i(TAG, "No Bluetooth Service (Bluetooth Hardware Not Present)");} else {t.traceBegin("StartBluetoothService");mSystemServiceManager.startService(BluetoothService.class);t.traceEnd();}...
}步骤2：BluetoothService构造函数中执行创建BluetoothManagerService
mBluetoothManagerService = new BluetoothManagerService(context);
BluetoothManagerService(Context context) {Slog.e(TAG, "new BluetoothManagerService");// BluetoothManagerService的私有类，主要用于处理一些messagemHandler = new BluetoothHandler(IoThread.get().getLooper()); mContext = context;mWirelessConsentRequired = context.getResources().getBoolean(com.android.internal.R.bool.config_wirelessConsentRequired);mCrashes = 0;mBluetooth = null;mBluetoothBinder = null;mBluetoothGatt = null;mBinding = false;mUnbinding = false;mEnable = false;mState = BluetoothAdapter.STATE_OFF;mQuietEnableExternal = false;mEnableExternal = false;mAddress = null;mName = null;mErrorRecoveryRetryCounter = 0;mContentResolver = context.getContentResolver();// Observe BLE scan only mode settings change.registerForBleScanModeChange();mCallbacks = new RemoteCallbackList<IBluetoothManagerCallback>();mStateChangeCallbacks = new RemoteCallbackList<IBluetoothStateChangeCallback>();mIsHearingAidProfileSupported = context.getResources().getBoolean(com.android.internal.R.bool.config_hearing_aid_profile_supported);// TODO: We need a more generic way to initialize the persist keys of FeatureFlagUtilsString value = SystemProperties.get(FeatureFlagUtils.PERSIST_PREFIX + FeatureFlagUtils.HEARING_AID_SETTINGS);if (!TextUtils.isEmpty(value)) {boolean isHearingAidEnabled = Boolean.parseBoolean(value);Log.v(TAG, "set feature flag HEARING_AID_SETTINGS to " + isHearingAidEnabled);FeatureFlagUtils.setEnabled(context, FeatureFlagUtils.HEARING_AID_SETTINGS, isHearingAidEnabled);if (isHearingAidEnabled && !mIsHearingAidProfileSupported) {// Overwrite to enable support by FeatureFlagmIsHearingAidProfileSupported = true;}}IntentFilter filter = new IntentFilter();filter.addAction(BluetoothAdapter.ACTION_LOCAL_NAME_CHANGED);filter.addAction(BluetoothAdapter.ACTION_BLUETOOTH_ADDRESS_CHANGED);filter.addAction(Intent.ACTION_SETTING_RESTORED);filter.setPriority(IntentFilter.SYSTEM_HIGH_PRIORITY);mContext.registerReceiver(mReceiver, filter);loadStoredNameAndAddress();if (isBluetoothPersistedStateOn()) {if (DBG) {Slog.d(TAG, "Startup: Bluetooth persisted state is ON.");}mEnableExternal = true;}String airplaneModeRadios =Settings.Global.getString(mContentResolver, Settings.Global.AIRPLANE_MODE_RADIOS);if (airplaneModeRadios == null || airplaneModeRadios.contains(Settings.Global.RADIO_BLUETOOTH)) {mBluetoothAirplaneModeListener = new BluetoothAirplaneModeListener(this, IoThread.get().getLooper(), context);}int systemUiUid = -1;// Check if device is configured with no home screen, which implies no SystemUI.boolean noHome = mContext.getResources().getBoolean(R.bool.config_noHomeScreen);if (!noHome) {PackageManagerInternal pm = LocalServices.getService(PackageManagerInternal.class);systemUiUid = pm.getPackageUid(pm.getSystemUiServiceComponent().getPackageName(),MATCH_SYSTEM_ONLY, USER_SYSTEM);}if (systemUiUid >= 0) {Slog.d(TAG, "Detected SystemUiUid: " + Integer.toString(systemUiUid));} else {// Some platforms, such as wearables do not have a system ui.Slog.w(TAG, "Unable to resolve SystemUI's UID.");}mSystemUiUid = systemUiUid;}步骤3：启动默认用户调用的方法处理
public void onSwitchUser(int userHandle) {if (!mInitialized) {initialize();} else {mBluetoothManagerService.handleOnSwitchUser(userHandle);}
}onSwitchUser 是 Android 框架中的一个回调方法，用于在用户切换时接收通知。当有多个用户在同一个设备上使用时，可以使用此方法来执行一些特定于用户的操作，例如切换到其它用户时保存当前用户的状态并加载新用户的数据。
在 Android 系统中，只有在设备启用多用户功能并启用多个用户帐户时才会调用此方法。在单用户设备上，该方法不会被调用。
当一个用户从其它用户切换到当前用户时，系统会调用 onSwitchUser 方法。
当设备启动时，如果已经启用了多用户功能，则系统会自动创建一个默认的用户，并在该用户的环境下启动应用程序。此时，onSwitchUser 方法也会被调用，此时传递给方法的 userId 参数为默认用户的 ID。
备注：该方法已经在 Android 12 中被标记为过时。因此，在新的应用程序中，应该避免使用该方法，而应该考虑使用更现代的 Android 架构组件或 API 来实现多用户管理和数据保护。
private void initialize() {if (!mInitialized) {mBluetoothManagerService.handleOnBootPhase();mInitialized = true;}
}public void handleOnBootPhase() {...final boolean isSafeMode = mContext.getPackageManager().isSafeMode();if (mEnableExternal && isBluetoothPersistedStateOnBluetooth() && !isSafeMode) {if (DBG) {Slog.d(TAG, "Auto-enabling Bluetooth.");}//调用sendEnableMsg(mQuietEnableExternal,BluetoothProtoEnums.ENABLE_DISABLE_REASON_SYSTEM_BOOT,mContext.getPackageName());} ....
}步骤4：BluetoothManagerService.java处理enable
private void sendEnableMsg(boolean quietMode, int reason, String packageName) {mHandler.sendMessage(mHandler.obtainMessage(MESSAGE_ENABLE, quietMode ? 1 : 0, 0));addActiveLog(reason, packageName, true);mLastEnabledTime = SystemClock.elapsedRealtime();
}public void handleMessage(Message msg)
{switch (msg.what){case MESSAGE_ENABLE:handleEnable(mQuietEnable);break;}
}private void handleEnable(boolean quietMode)
{...Intent i = new Intent(IBluetooth.class.getName());if (!doBind(i, mConnection, Context.BIND_AUTO_CREATE | Context.BIND_IMPORTANT,UserHandle.CURRENT)) {mHandler.removeMessages(MESSAGE_TIMEOUT_BIND);} else {mBinding = true;}...
}bond后会调用这个函数onServiceConnected
private class BluetoothServiceConnection implements ServiceConnection {public void onServiceConnected(ComponentName componentName, IBinder service) {String name = componentName.getClassName();if (DBG) {Slog.d(TAG, "BluetoothServiceConnection: " + name);}Message msg = mHandler.obtainMessage(MESSAGE_BLUETOOTH_SERVICE_CONNECTED);if (name.equals("com.android.bluetooth.btservice.AdapterService")) {msg.arg1 = SERVICE_IBLUETOOTH;} else if (name.equals("com.android.bluetooth.gatt.GattService")) {msg.arg1 = SERVICE_IBLUETOOTHGATT;} else {Slog.e(TAG, "Unknown service connected: " + name);return;}msg.obj = service;mHandler.sendMessage(msg);}public void onServiceDisconnected(ComponentName componentName) {// Called if we unexpectedly disconnect.String name = componentName.getClassName();if (DBG) {Slog.d(TAG, "BluetoothServiceConnection, disconnected: " + name);}Message msg = mHandler.obtainMessage(MESSAGE_BLUETOOTH_SERVICE_DISCONNECTED);if (name.equals("com.android.bluetooth.btservice.AdapterService")) {msg.arg1 = SERVICE_IBLUETOOTH;} else if (name.equals("com.android.bluetooth.gatt.GattService")) {msg.arg1 = SERVICE_IBLUETOOTHGATT;} else {Slog.e(TAG, "Unknown service disconnected: " + name);return;}mHandler.sendMessage(msg);}
}public void handleMessage(Message msg)
{switch (msg.what){case MESSAGE_BLUETOOTH_SERVICE_CONNECTED:...mBluetooth.registerCallback(mBluetoothCallback);...sendBluetoothServiceUpCallback();...mBluetooth.enable(mQuietEnable);break;}
}步骤5：AdapterService.java处理enable
注意在里面还有一个AdapterServiceBinder的类，不是这个类下面的enable
public synchronized boolean enable(boolean quietMode) {// Enforce the user restriction for disallowing Bluetooth if it was set.if (mUserManager.hasUserRestriction(UserManager.DISALLOW_BLUETOOTH, UserHandle.SYSTEM)) {debugLog("enable() called when Bluetooth was disallowed");return false;}Log.e(TAG, "AdapterService enable");debugLog("enable() - Enable called with quiet mode status = " + quietMode);mQuietmode = quietMode;mAdapterStateMachine.sendMessage(AdapterState.BLE_TURN_ON);return true;
}这个会触发status machine，会调用到OffState中processMessage
public boolean processMessage(Message msg) {switch (msg.what) {case BLE_TURN_ON:transitionTo(mTurningBleOnState);break;default:infoLog("Unhandled message - " + messageString(msg.what));return false;}return true;
}然后进入到TurningBleOnState类中的enter
public void enter() {super.enter();sendMessageDelayed(BLE_START_TIMEOUT, BLE_START_TIMEOUT_DELAY);mAdapterService.bringUpBle();
}void bringUpBle() {...//Start Gatt servicesetProfileServiceState(GattService.class, BluetoothAdapter.STATE_ON);
}开启gattservice服务
另外，ProfileService的状态改变会触发AdapterService的onProfileServiceStateChanged
public void onProfileServiceStateChanged(ProfileService profile, int state) {if (state != BluetoothAdapter.STATE_ON && state != BluetoothAdapter.STATE_OFF) {throw new IllegalArgumentException(BluetoothAdapter.nameForState(state));}Message m = mHandler.obtainMessage(MESSAGE_PROFILE_SERVICE_STATE_CHANGED);m.obj = profile;m.arg1 = state;mHandler.sendMessage(m);
}private void processProfileServiceStateChanged(ProfileService profile, int state) {switch (state) {case BluetoothAdapter.STATE_ON:if (!mRegisteredProfiles.contains(profile)) {Log.e(TAG, profile.getName() + " not registered (STATE_ON).");return;}if (mRunningProfiles.contains(profile)) {Log.e(TAG, profile.getName() + " already running.");return;}mRunningProfiles.add(profile);if (GattService.class.getSimpleName().equals(profile.getName())) {Log.e(TAG, "processProfileServiceStateChanged enableNative");// 这个地方就是调用libjni.so的方法，通过jni native调用enableNative();} else if (mRegisteredProfiles.size() == Config.getSupportedProfiles().length&& mRegisteredProfiles.size() == mRunningProfiles.size()) {mAdapterProperties.onBluetoothReady();updateUuids();setBluetoothClassFromConfig();initProfileServices();getAdapterPropertyNative(AbstractionLayer.BT_PROPERTY_LOCAL_IO_CAPS);getAdapterPropertyNative(AbstractionLayer.BT_PROPERTY_LOCAL_IO_CAPS_BLE);mAdapterStateMachine.sendMessage(AdapterState.BREDR_STARTED);}break;default:Log.e(TAG, "Unhandled profile state: " + state);}
}NOTED：能够直接调用到libbluetooth_jni.so的原因是AdapterApp 类在启动的时候加载了
public class AdapterApp extends Application
{private static final String TAG = "BluetoothAdapterApp";private static final boolean DBG = false;//For Debugging onlyprivate static int sRefCount = 0;static {if (DBG) {Log.d(TAG, "Loading JNI Library");}System.loadLibrary("bluetooth_jni");}...
}然后这个动作会触发com_android_bluetooth_btservice_adapterService.cpp中的
jint JNI_OnLoad(JavaVM* jvm, void* reserved) {JNIEnv* e;int status;ALOGE("Bluetooth Adapter Service : loading JNI\\n");ALOGV("Bluetooth Adapter Service : loading JNI\\n");// Check JNI versionif (jvm->GetEnv((void**)&e, JNI_VERSION_1_6)) {ALOGE("JNI version mismatch error");return JNI_ERR;}status = android::register_com_android_bluetooth_btservice_AdapterService(e);if (status < 0) {ALOGE("jni adapter service registration failure, status: %d", status);return JNI_ERR;}status =android::register_com_android_bluetooth_btservice_BluetoothKeystore(e);if (status < 0) {ALOGE("jni BluetoothKeyStore registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_hfp(e);if (status < 0) {ALOGE("jni hfp registration failure, status: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_hfpclient(e);if (status < 0) {ALOGE("jni hfp client registration failure, status: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_a2dp(e);if (status < 0) {ALOGE("jni a2dp source registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_a2dp_sink(e);if (status < 0) {ALOGE("jni a2dp sink registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_avrcp_target(e);if (status < 0) {ALOGE("jni new avrcp target registration failure: %d", status);}status = android::register_com_android_bluetooth_avrcp_controller(e);if (status < 0) {ALOGE("jni avrcp controller registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_hid_host(e);if (status < 0) {ALOGE("jni hid registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_hid_device(e);if (status < 0) {ALOGE("jni hidd registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_pan(e);if (status < 0) {ALOGE("jni pan registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_gatt(e);if (status < 0) {ALOGE("jni gatt registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_sdp(e);if (status < 0) {ALOGE("jni sdp registration failure: %d", status);return JNI_ERR;}status = android::register_com_android_bluetooth_hearing_aid(e);if (status < 0) {ALOGE("jni hearing aid registration failure: %d", status);return JNI_ERR;}return JNI_VERSION_1_6;
}
步骤6：bluetooth jni的enableNative处理
static jboolean enableNative(JNIEnv* env, jobject obj) {ALOGV("%s", __func__);if (!sBluetoothInterface) return JNI_FALSE;int ret = sBluetoothInterface->enable();return (ret == BT_STATUS_SUCCESS || ret == BT_STATUS_DONE) ? JNI_TRUE: JNI_FALSE;
}其中sBluetoothInterface 是hal接口，定义如下：
typedef struct {/** set to sizeof(bt_interface_t) */size_t size;/**
* Opens the interface and provides the callback routines
* to the implemenation of this interface.
* The |is_atv| flag indicates whether the local device is an Android TV
*/int (*init)(bt_callbacks_t* callbacks, bool is_atv);/** Enable Bluetooth. */int (*enable)(bool guest_mode);/** Disable Bluetooth. */int (*disable)(void);/** Closes the interface. */void (*cleanup)(void);/** Get all Bluetooth Adapter properties at init */int (*get_adapter_properties)(void);/** Get Bluetooth Adapter property of 'type' */int (*get_adapter_property)(bt_property_type_t type);/** Set Bluetooth Adapter property of 'type' *//* Based on the type, val shall be one of
* RawAddress or bt_bdname_t or bt_scanmode_t etc
*/int (*set_adapter_property)(const bt_property_t *property);/** Get all Remote Device properties */int (*get_remote_device_properties)(RawAddress *remote_addr);/** Get Remote Device property of 'type' */int (*get_remote_device_property)(RawAddress *remote_addr,bt_property_type_t type);/** Set Remote Device property of 'type' */int (*set_remote_device_property)(RawAddress *remote_addr,const bt_property_t *property);/** Get Remote Device's service record for the given UUID */int (*get_remote_service_record)(const RawAddress& remote_addr,const bluetooth::Uuid& uuid);/** Start SDP to get remote services */int (*get_remote_services)(RawAddress *remote_addr);/** Start Discovery */int (*start_discovery)(void);/** Cancel Discovery */int (*cancel_discovery)(void);/** Create Bluetooth Bonding */int (*create_bond)(const RawAddress *bd_addr, int transport);/** Create Bluetooth Bond using out of band data */int (*create_bond_out_of_band)(const RawAddress *bd_addr, int transport,const bt_out_of_band_data_t *oob_data);/** Remove Bond */int (*remove_bond)(const RawAddress *bd_addr);/** Cancel Bond */int (*cancel_bond)(const RawAddress *bd_addr);/**
* Get the connection status for a given remote device.
* return value of 0 means the device is not connected,
* non-zero return status indicates an active connection.
*/int (*get_connection_state)(const RawAddress *bd_addr);/** BT Legacy PinKey Reply *//** If accept==FALSE, then pin_len and pin_code shall be 0x0 */int (*pin_reply)(const RawAddress *bd_addr, uint8_t accept,uint8_t pin_len, bt_pin_code_t *pin_code);/** BT SSP Reply - Just Works, Numeric Comparison and Passkey
* passkey shall be zero for BT_SSP_VARIANT_PASSKEY_COMPARISON &
* BT_SSP_VARIANT_CONSENT
* For BT_SSP_VARIANT_PASSKEY_ENTRY, if accept==FALSE, then passkey
* shall be zero */int (*ssp_reply)(const RawAddress *bd_addr, bt_ssp_variant_t variant,uint8_t accept, uint32_t passkey);/** Get Bluetooth profile interface */const void* (*get_profile_interface) (const char *profile_id);/** Bluetooth Test Mode APIs - Bluetooth must be enabled for these APIs *//* Configure DUT Mode - Use this mode to enter/exit DUT mode */int (*dut_mode_configure)(uint8_t enable);/* Send any test HCI (vendor-specific) command to the controller. Must be in DUT Mode */int (*dut_mode_send)(uint16_t opcode, uint8_t *buf, uint8_t len);/** BLE Test Mode APIs *//* opcode MUST be one of: LE_Receiver_Test, LE_Transmitter_Test, LE_Test_End */int (*le_test_mode)(uint16_t opcode, uint8_t *buf, uint8_t len);/** Sets the OS call-out functions that bluedroid needs for alarms and wake locks.
* This should be called immediately after a successful |init|.
*/int (*set_os_callouts)(bt_os_callouts_t *callouts);/** Read Energy info details - return value indicates BT_STATUS_SUCCESS or BT_STATUS_NOT_READY
* Success indicates that the VSC command was sent to controller
*/int (*read_energy_info)();/**
* Native support for dumpsys function
* Function is synchronous and |fd| is owned by caller.
* |arguments| are arguments which may affect the output, encoded as
* UTF-8 strings.
*/void (*dump)(int fd, const char **arguments);/**
* Clear /data/misc/bt_config.conf and erase all stored connections
*/int (*config_clear)(void);/**
* Clear (reset) the dynamic portion of the device interoperability database.
*/void (*interop_database_clear)(void);/**
* Add a new device interoperability workaround for a remote device whose
* first |len| bytes of the its device address match |addr|.
* NOTE: |feature| has to match an item defined in interop_feature_t (interop.h).
*/void (*interop_database_add)(uint16_t feature, const RawAddress *addr, size_t len);
} bt_interface_t;这个enable是调用libbluetooth.so中的enable，也就是bluedroid bluetooth.cc或者android8之前的bluetooth.c
static int enable() {if (!interface_ready()) return BT_STATUS_NOT_READY;stack_manager_get_interface()->start_up_stack_async();return BT_STATUS_SUCCESS;
}然后就是走bluedroid流程了，host的初始化流程可以看我协议栈的其他文章
步骤7：底层bluedroid enable成功后回调处理
bluedroid底层enable跟controller交互成功后，调用这个函数，通过HAL_CBACK回调到bt service apk的jni
static void event_signal_stack_up(UNUSED_ATTR void* context) {// Notify BTIF connect queue that we've brought up the stack. It's// now time to dispatch all the pending profile connect requests.btif_queue_connect_next();HAL_CBACK(bt_hal_cbacks, adapter_state_changed_cb, BT_STATE_ON);
}思考：为什么能调用到callback呢？
是因为adapterService 服务启动的时候调用到onCreate方法，里面有
public void onCreate() {super.onCreate();debugLog("onCreate()");...// 调用jni的方法initNative(isGuest(), isNiapMode(), configCompareResult, isAtvDevice);...
}static bool initNative(JNIEnv* env, jobject obj, jboolean isGuest,jboolean isNiapMode, int configCompareResult,jboolean isAtvDevice) {ALOGV("%s", __func__);// 注册jni的callback到bluedroid，bluedroid有回调的时候回调用到sBluetoothCallbacksint ret = sBluetoothInterface->init(&sBluetoothCallbacks, isGuest == JNI_TRUE ? 1 : 0,isNiapMode == JNI_TRUE ? 1 : 0, configCompareResult,isAtvDevice == JNI_TRUE ? 1 : 0);if (ret != BT_STATUS_SUCCESS) {ALOGE("Error while setting the callbacks: %d\\n", ret);sBluetoothInterface = NULL;return JNI_FALSE;}}好了，回归会提，如果bluedroid enable成功后，会调用到sBluetoothCallbacks的adapter_state_change_callback函数
static void adapter_state_change_callback(bt_state_t status) {ALOGE("Bluetooth adapter_state_change_callback:%d\\n",status);CallbackEnv sCallbackEnv(__func__);if (!sCallbackEnv.valid()) return;ALOGV("%s: Status is: %d", __func__, status);// 通过jni的回调方法调用到AdapterService的stateChangeCallbacksCallbackEnv->CallVoidMethod(sJniCallbacksObj, method_stateChangeCallback,(jint)status);
}步骤8：bt service的处理enable成功后的回调过程
void stateChangeCallback(int status) {Log.e(TAG, "stateChangeCallback:"+status);if (status == AbstractionLayer.BT_STATE_OFF) {debugLog("stateChangeCallback: disableNative() completed");mAdapterStateMachine.sendMessage(AdapterState.BLE_STOPPED);} else if (status == AbstractionLayer.BT_STATE_ON) {mAdapterStateMachine.sendMessage(AdapterState.BLE_STARTED);} else {Log.e(TAG, "Incorrect status " + status + " in stateChangeCallback");}
}此时进入这个类中的processMessage处理
public boolean processMessage(Message msg) {switch (msg.what) {case BLE_STARTED:transitionTo(mBleOnState);break;case BLE_START_TIMEOUT:errorLog(messageString(msg.what));transitionTo(mTurningBleOffState);break;default:infoLog("Unhandled message - " + messageString(msg.what));return false;}return true;
}迁徙到mBleOnState状态，然后处理，另外状态概念，会触发AdapterService.java中的updateAdapterState
void updateAdapterState(int prevState, int newState) {mAdapterProperties.setState(newState);invalidateBluetoothGetStateCache();if (mCallbacks != null) {int n = mCallbacks.beginBroadcast();debugLog("updateAdapterState() - Broadcasting state " + BluetoothAdapter.nameForState(newState) + " to " + n + " receivers.");for (int i = 0; i < n; i++) {try {mCallbacks.getBroadcastItem(i).onBluetoothStateChange(prevState, newState);} catch (RemoteException e) {debugLog("updateAdapterState() - Callback #" + i + " failed (" + e + ")");}}mCallbacks.finishBroadcast();}....
}private final IBluetoothCallback mBluetoothCallback = new IBluetoothCallback.Stub() {@Overridepublic void onBluetoothStateChange(int prevState, int newState) throws RemoteException {Message msg =mHandler.obtainMessage(MESSAGE_BLUETOOTH_STATE_CHANGE, prevState, newState);mHandler.sendMessage(msg);}
};case处理
case MESSAGE_BLUETOOTH_STATE_CHANGE: {....bluetoothStateChangeHandler(prevState, newState);break;
}private void bluetoothStateChangeHandler(int prevState, int newState) {if (newState == BluetoothAdapter.STATE_BLE_ON || newState == BluetoothAdapter.STATE_OFF) {.......continueFromBleOnState();}}private void continueFromBleOnState() {...mBluetooth.onLeServiceUp();...
}public void onLeServiceUp() {AdapterService service = getService();if (service == null || !callerIsSystemOrActiveUser(TAG, "onLeServiceUp")) {return;}enforceBluetoothPrivilegedPermission(service);service.mAdapterStateMachine.sendMessage(AdapterState.USER_TURN_ON);
}private class BleOnState extends BaseAdapterState {@Overrideint getStateValue() {return BluetoothAdapter.STATE_BLE_ON;}@Overridepublic boolean processMessage(Message msg) {switch (msg.what) {case USER_TURN_ON:transitionTo(mTurningOnState);break;case BLE_TURN_OFF:transitionTo(mTurningBleOffState);break;default:infoLog("Unhandled message - " + messageString(msg.what));return false;}return true;}
}然后进入到TurningOnState class的enter处理
public void enter() {super.enter();sendMessageDelayed(BREDR_START_TIMEOUT, BREDR_START_TIMEOUT_DELAY);mAdapterService.startProfileServices();
}步骤9：开启所有profile的service
void startProfileServices() {...setAllProfileServiceStates(supportedProfileServices, BluetoothAdapter.STATE_ON);}private static final ProfileConfig[] PROFILE_SERVICES_AND_FLAGS = {new ProfileConfig(HeadsetService.class, R.bool.profile_supported_hs_hfp,(1 << BluetoothProfile.HEADSET)),new ProfileConfig(A2dpService.class, R.bool.profile_supported_a2dp,(1 << BluetoothProfile.A2DP)),new ProfileConfig(A2dpSinkService.class, R.bool.profile_supported_a2dp_sink,(1 << BluetoothProfile.A2DP_SINK)),new ProfileConfig(HidHostService.class, R.bool.profile_supported_hid_host,(1 << BluetoothProfile.HID_HOST)),new ProfileConfig(PanService.class, R.bool.profile_supported_pan,(1 << BluetoothProfile.PAN)),new ProfileConfig(GattService.class, R.bool.profile_supported_gatt,(1 << BluetoothProfile.GATT)),new ProfileConfig(BluetoothMapService.class, R.bool.profile_supported_map,(1 << BluetoothProfile.MAP)),new ProfileConfig(HeadsetClientService.class, R.bool.profile_supported_hfpclient,(1 << BluetoothProfile.HEADSET_CLIENT)),new ProfileConfig(AvrcpTargetService.class, R.bool.profile_supported_avrcp_target,(1 << BluetoothProfile.AVRCP)),new ProfileConfig(AvrcpControllerService.class,R.bool.profile_supported_avrcp_controller,(1 << BluetoothProfile.AVRCP_CONTROLLER)),new ProfileConfig(SapService.class, R.bool.profile_supported_sap,(1 << BluetoothProfile.SAP)),new ProfileConfig(PbapClientService.class, R.bool.profile_supported_pbapclient,(1 << BluetoothProfile.PBAP_CLIENT)),new ProfileConfig(MapClientService.class, R.bool.profile_supported_mapmce,(1 << BluetoothProfile.MAP_CLIENT)),new ProfileConfig(HidDeviceService.class, R.bool.profile_supported_hid_device,(1 << BluetoothProfile.HID_DEVICE)),new ProfileConfig(BluetoothOppService.class, R.bool.profile_supported_opp,(1 << BluetoothProfile.OPP)),new ProfileConfig(BluetoothPbapService.class, R.bool.profile_supported_pbap,(1 << BluetoothProfile.PBAP)),new ProfileConfig(HearingAidService.class,com.android.internal.R.bool.config_hearing_aid_profile_supported,(1 << BluetoothProfile.HEARING_AID))};因为我们之前在前面说过，开启成功后就会调用profileService change的消息，所以如下
private void processProfileServiceStateChanged(ProfileService profile, int state) {switch (state) {case BluetoothAdapter.STATE_ON:........if (GattService.class.getSimpleName().equals(profile.getName())) {enableNative();} else if (mRegisteredProfiles.size() == Config.getSupportedProfiles().length&& mRegisteredProfiles.size() == mRunningProfiles.size()) { //所有ProfileService都启动完毕.......mAdapterStateMachine.sendMessage(AdapterState.BREDR_STARTED);}break;public boolean processMessage(Message msg) {switch (msg.what) {case BREDR_STARTED:transitionTo(mOnState);break;}return true;
}private void bluetoothStateChangeHandler(int prevState, int newState) {...sendBluetoothStateCallback(isUp); //广播发出数据sendBleStateChanged(prevState, newState);...
}