Android4.4(MT8685)源码WIFI--初始化1

在Android系统启动的时候，会在./frameworks/base/services/java/com/android/server/SystemServer.java类中启动许多服务，其中和Wifi相关的服务就在这里初始化。在SystemServer的main方法中，我们可以看到

thr.initAndLoop();

这里调用了它的内部类对象的initAndLoop方法，在这个方法的作用主要就是初始化系统启动需要加载的服务的，我们在这个方法中可以找到

try {

Slog.i(TAG, "Wi-Fi Service");

wifi = new WifiService(context);

ServiceManager.addService(Context.WIFI_SERVICE, wifi);

} catch (Throwable e) {

reportWtf("starting Wi-Fi Service", e);

}

try {

Slog.i(TAG, "Connectivity Service");

connectivity = new ConnectivityService(

context, networkManagement, networkStats, networkPolicy);

ServiceManager.addService(Context.CONNECTIVITY_SERVICE, connectivity);

networkStats.bindConnectivityManager(connectivity);

networkPolicy.bindConnectivityManager(connectivity);

wifiP2p.connectivityServiceReady();

wifi.checkAndStartWifi();

} catch (Throwable e) {

reportWtf("starting Connectivity Service", e);

}

这里我们可以看到初始化了一个WifiService和ConnectivityService对象，并把这2个对象注册到ServiceManager中，然后通过创建的对象wifi 来调用checkAndStartWifi方法，具体的WifiService的分析我们下一章再做详细介绍，现在我们简单分析下ConnectivityService。

ConnectivityService是管理系统中所有的数据连接服务，其中就包括Wifi，我们来看看它的构造函数，路径：./frameworks/base/services/java/com/android/server/ConnectivityService.java

public ConnectivityService(Context context, INetworkManagementService netd,

INetworkStatsService statsService, INetworkPolicyManager policyManager) {

// Currently, omitting a NetworkFactory will create one internally

// TODO: create here when we have cleaner WiMAX support

this(context, netd, statsService, policyManager, null);

}

这里就是调用了同名的构造方法

public ConnectivityService(Context context, INetworkManagementService netManager,

INetworkStatsService statsService, INetworkPolicyManager policyManager,

NetworkFactory netFactory) {

if (DBG) log("ConnectivityService starting up");

HandlerThread handlerThread = new HandlerThread("ConnectivityServiceThread");

handlerThread.start();

mHandler = new InternalHandler(handlerThread.getLooper());

mTrackerHandler = new NetworkStateTrackerHandler(handlerThread.getLooper());

// Create and start trackers for hard-coded networks

for (int targetNetworkType : mPriorityList) {

final NetworkConfig config = mNetConfigs[targetNetworkType];

final NetworkStateTracker tracker;

try {

/** M: Hotspot Manager @{*/

if(config.radio == TYPE_USB){

log("new UsbDataStateTracker");

mNetTrackers[targetNetworkType] = new UsbDataStateTracker(targetNetworkType, config.name, mNetd);

mNetTrackers[targetNetworkType].startMonitoring(context, mTrackerHandler);

continue;

}

if(true == FeatureOption.MTK_ALPS_BOX_SUPPORT && config.radio == TYPE_ETHERNET){

if (DBG) log("Starting Ethernet Service.");

mNetTrackers[TYPE_ETHERNET] = makeEthStateTracker(context);

if(mNetTrackers[TYPE_ETHERNET] != null){

if (DBG) log("mNetTrackers[TYPE_ETHERNET] != null");

mNetTrackers[TYPE_ETHERNET].startMonitoring(context, mTrackerHandler);

if (config.isDefault()) {

mNetTrackers[TYPE_ETHERNET].reconnect();

}

}

continue;

}

/*@} */

/*@} */

///M:new a Teledongle Data Tracker @by mtk94127 @{

if(FeatureOption.MTK_EXTERNAL_DONGLE_SUPPORT && (config.radio == TYPE_TEDONGLE)) {

log("new TedongleDataStateTracker");

mNetTrackers[targetNetworkType] = makeTedongleDataTracker();

log("new TedongleDataStateTracker medium!");

mNetTrackers[targetNetworkType].startMonitoring(context, mTrackerHandler);

log("new TedongleDataStateTracker end!");

continue;

}

///M:@}

tracker = netFactory.createTracker(targetNetworkType, config);

mNetTrackers[targetNetworkType] = tracker;

} catch (IllegalArgumentException e) {

Slog.e(TAG, "Problem creating " + getNetworkTypeName(targetNetworkType)

+ " tracker: " + e);

continue;

}

tracker.startMonitoring(context, mTrackerHandler);

if (config.isDefault()) {

tracker.reconnect();

}

}

}

这里根据com.android.internal.R.array.networkAttributes配置的属性去创建一个个tracker，并监听其状态，tracker.startMonitoring(context, mTrackerHandler);可以看出tracker可以通过mTrackerHandler向ConnectivityService发送消息，这些消息有

/**

* The network state has changed and the NetworkInfo object

* contains the new state.

*

* msg.what = EVENT_STATE_CHANGED

* msg.obj = NetworkInfo object

*/

public static final int EVENT_STATE_CHANGED = BASE_NETWORK_STATE_TRACKER;

/**

* msg.what = EVENT_CONFIGURATION_CHANGED

* msg.obj = NetworkInfo object

*/

public static final int EVENT_CONFIGURATION_CHANGED = BASE_NETWORK_STATE_TRACKER + 1;

/**

* msg.what = EVENT_RESTORE_DEFAULT_NETWORK

* msg.obj = FeatureUser object

*/

public static final int EVENT_RESTORE_DEFAULT_NETWORK = BASE_NETWORK_STATE_TRACKER + 2;

/**

* msg.what = EVENT_NETWORK_SUBTYPE_CHANGED

* msg.obj = NetworkInfo object

*/

public static final int EVENT_NETWORK_SUBTYPE_CHANGED = BASE_NETWORK_STATE_TRACKER + 3;

/**

* msg.what = EVENT_NETWORK_CONNECTED

* msg.obj = LinkProperties object

*/

public static final int EVENT_NETWORK_CONNECTED = BASE_NETWORK_STATE_TRACKER + 4;

/**

* msg.what = EVENT_NETWORK_CONNECTION_DISCONNECTED

* msg.obj = LinkProperties object, same iface name

*/

public static final int EVENT_NETWORK_DISCONNECTED = BASE_NETWORK_STATE_TRACKER + 5;

当WiFi的连接AP成功后，就会想 ConnectivityService发送一个EVENT_STATE_CHANGED消息。

接着我们来看创建了哪些tracker，找到createTracker方法

@Override

public NetworkStateTracker createTracker(int targetNetworkType, NetworkConfig config) {

switch (config.radio) {

case TYPE_WIFI:

return new WifiStateTracker(targetNetworkType, config.name);

case TYPE_MOBILE:

return new MobileDataStateTracker(targetNetworkType, config.name);

case TYPE_DUMMY:

return new DummyDataStateTracker(targetNetworkType, config.name);

case TYPE_BLUETOOTH:

return BluetoothTetheringDataTracker.getInstance();

case TYPE_WIMAX:

return makeWimaxStateTracker(mContext, mTrackerHandler);

case TYPE_CSD:

return new CsdStateTracker(targetNetworkType, config.name);

default:

throw new IllegalArgumentException(

"Trying to create a NetworkStateTracker for an unknown radio type: "

+ config.radio);

}

}

这里我们主要关注TYPE_WIFI，创建了一个WifiStateTracker对象，进入到WifiStateTracker的构造方法

public WifiStateTracker(int netType, String networkName) {

///M:@{

mNetType = netType;

///@}

mNetworkInfo = new NetworkInfo(netType, 0, networkName, "");

mLinkProperties = new LinkProperties();

mLinkCapabilities = new LinkCapabilities();

mNetworkInfo.setIsAvailable(false);

setTeardownRequested(false);

}

接着调用startMonitoring

/**

* Begin monitoring wifi connectivity

*/

public void startMonitoring(Context context, Handler target) {

mCsHandler = target;

mContext = context;

mWifiManager = (WifiManager) mContext.getSystemService(Context.WIFI_SERVICE);

IntentFilter filter = new IntentFilter();

///M:seperate p2p and wifi @{

if (mNetType == ConnectivityManager.TYPE_WIFI) {

filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);

filter.addAction(WifiManager.LINK_CONFIGURATION_CHANGED_ACTION);

}

///@}

mWifiStateReceiver = new WifiStateReceiver();

mContext.registerReceiver(mWifiStateReceiver, filter);

}

这里就是注册了一个广播用于接收NETWORK_STATE_CHANGED_ACTION和LINK_CONFIGURATION_CHANGED_ACTION广播，ConnectivityService我们就分析到这里，下一章我们将详细分析WifiService。