[Bluetooth] Android Bluetooth

Bluetooth相关的服务在SystemServer.java中被启动。

                Slog.i(TAG, "Bluetooth Service");                bluetooth = new BluetoothService(context);                ServiceManager.addService(BluetoothAdapter.BLUETOOTH_SERVICE, bluetooth);                bluetooth.initAfterRegistration();                if (!"0".equals(SystemProperties.get("system_init.startaudioservice"))) {                    bluetoothA2dp = new BluetoothA2dpService(context, bluetooth);                    ServiceManager.addService(BluetoothA2dpService.BLUETOOTH_A2DP_SERVICE,                                              bluetoothA2dp);                    bluetooth.initAfterA2dpRegistration();                }                int airplaneModeOn = Settings.System.getInt(mContentResolver,                        Settings.System.AIRPLANE_MODE_ON, 0);                int bluetoothOn = Settings.Secure.getInt(mContentResolver,                            Settings.Secure.BLUETOOTH_ON, 0);                if (airplaneModeOn == 0 && bluetoothOn != 0) {                    bluetooth.enable();                        }

BluetoothService

frameworks/base/core/java/android/server/BluetoothService.java

    public synchronized void initAfterRegistration() {        mAdapter = BluetoothAdapter.getDefaultAdapter();        mBluetoothState = new BluetoothAdapterStateMachine(mContext, this, mAdapter);        mBluetoothState.start();        if (mContext.getResources().getBoolean            (com.android.internal.R.bool.config_bluetooth_adapter_quick_switch) &&            mBluetoothState.is_hot_off_enabled()) {            mBluetoothState.sendMessage(BluetoothAdapterStateMachine.TURN_HOT);        }            mEventLoop = mBluetoothState.getBluetoothEventLoop();    }        /** Bring up BT and persist BT on in settings */    public boolean enable() {        return enable(true, true);    }    /**     * Enable this Bluetooth device, asynchronously.     * This turns on/off the underlying hardware.     *     * @param saveSetting If true, persist the new state of BT in settings     * @param allowConnect If true, auto-connects device when BT is turned on     *                     and allows incoming A2DP/HSP connections     * @return True on success (so far)     */    public synchronized boolean enable(boolean saveSetting, boolean allowConnect) {        mContext.enforceCallingOrSelfPermission(BLUETOOTH_ADMIN_PERM,                                                "Need BLUETOOTH_ADMIN permission");        // Airplane mode can prevent Bluetooth radio from being turned on.        if (mIsAirplaneSensitive && isAirplaneModeOn() && !mIsAirplaneToggleable) {            return false;        }            mAllowConnect = allowConnect;        mBluetoothState.sendMessage(BluetoothAdapterStateMachine.USER_TURN_ON,                                           saveSetting);        return true;    }    

BluetoothAdapter

BluetoothAdapterStateMachine

    BluetoothAdapterStateMachine(Context context, BluetoothService bluetoothService,                                 BluetoothAdapter bluetoothAdapter) {                                                                                         super(TAG);        mContext = context;        mBluetoothService = bluetoothService;        mEventLoop = new BluetoothEventLoop(context, bluetoothAdapter, bluetoothService, this);                                                               mBluetoothOn = new BluetoothOn();        mSwitching = new Switching();          mHotOff = new HotOff();                mWarmUp = new WarmUp();                mPreWarmUp = new PreWarmUp();          mPowerOff = new PowerOff();            mPerProcessState = new PerProcessState();    }    private class PowerOff extends State {         @Override        public void enter() {            if (DBG) log("Enter PowerOff: " + getCurrentMessage().what);        }        @Override        public boolean processMessage(Message message) {            log("PowerOff process message: " + message.what);            boolean retValue = HANDLED;                switch(message.what) {                         case USER_TURN_ON:                                 // starts turning on BT module, broadcast this out                    broadcastState(BluetoothAdapter.STATE_TURNING_ON);                    transitionTo(mPreWarmUp);                          if (prepareBluetooth()) {                              // this is user request, save the setting                        if ((Boolean) message.obj) {                               persistSwitchSetting(true);                            }                        // We will continue turn the BT on all the way to the BluetoothOn state                        deferMessage(obtainMessage(TURN_ON_CONTINUE));                    } else {                        Log.e(TAG, "failed to prepare bluetooth, abort turning on");                        transitionTo(mPowerOff);                               broadcastState(BluetoothAdapter.STATE_OFF);                    }                    break;                case TURN_HOT:                    if (prepareBluetooth()) {                              transitionTo(mPreWarmUp);                          }                    break;             }        }        /**         * Turn on Bluetooth Module, Load firmware, and do all the preparation         * needed to get the Bluetooth Module ready but keep it not discoverable         * and not connectable.         * The last step of this method sets up the local service record DB.         * There will be a event reporting the status of the SDP setup.         */        private boolean prepareBluetooth() {            if (mBluetoothService.enableNative() != 0) {                return false;            }            // try to start event loop, give 2 attempts            int retryCount = 2;            boolean eventLoopStarted = false;            while ((retryCount-- > 0) && !eventLoopStarted) {                mEventLoop.start();                // it may take a moment for the other thread to do its                // thing.  Check periodically for a while.                int pollCount = 5;                while ((pollCount-- > 0) && !eventLoopStarted) {                    if (mEventLoop.isEventLoopRunning()) {                        eventLoopStarted = true;                        break;                    }                    try {                        Thread.sleep(100);                    } catch (InterruptedException e) {                        log("prepareBluetooth sleep interrupted: " + pollCount);                        break;                    }                }

BluetoothA2dpService

frameworks/base/core/java/android/server/BluetoothA2dpService.java