android清除系统wifi,Android系统wifi状态机WifiStateMachine

一、WifiStateMachine类分析

frameworks/base/wifi/java/android/net/wifi/WifiStateMachine.java

public class WifiStateMachine extends StateMachine {

public WifiStateMachine(Context context, String wlanInterface) {

//添加状态到状态机

addState(mDefaultState);

addState(mInitialState, mDefaultState);

//设置初始状态

setInitialState(mInitialState);

}

public void setWifiApEnabled(WifiConfiguration wifiConfig, boolean enable) {

if (enable) {

sendMessage(obtainMessage(CMD_LOAD_DRIVER, WIFI_AP_STATE_ENABLING, 0));

sendMessage(obtainMessage(CMD_START_AP, wifiConfig));

} else {

sendMessage(CMD_STOP_AP);

sendMessage(obtainMessage(CMD_UNLOAD_DRIVER, WIFI_AP_STATE_DISABLED, 0));

}

}

}

frameworks/base/core/java/com/android/internal/util/StateMachine.java

public class StateMachine {

//设置状态机的下一个状态

protected final void transitionTo(IState destState) {

mSmHandler.transitionTo(destState);

}

//增加状态到状态队列

protected final void addState(State state, State parent) {

mSmHandler.addState(state, parent);

}

//设置初始状态

private final void setInitialState(State initialState) {

if (mDbg) Log.d(TAG, "setInitialState: initialState=" + initialState.getName());

mInitialState = initialState;

}

//获取状态机当前状态

protected final IState getCurrentState() {

return mSmHandler.getCurrentState();

}

//向状态机发送消息

public final void sendMessage(Message msg) {

// mSmHandler can be null if the state machine has quit.

if (mSmHandler == null) return;

mSmHandler.sendMessage(msg);

}

///

private static class SmHandler extends Handler {

//设置状态机的下一个状态

private final void transitionTo(IState destState) {

mDestState = (State) destState;

if (mDbg) Log.d(TAG, "transitionTo: destState=" + mDestState.getName());

}

//增加状态到状态队列

private final StateInfo addState(State state, State parent) {

if (mDbg) {

Log.d(TAG, "addStateInternal: E state=" + state.getName()

+ ",parent=" + ((parent == null) ? "" : parent.getName()));

}

StateInfo parentStateInfo = null;

if (parent != null) {

parentStateInfo = mStateInfo.get(parent);

if (parentStateInfo == null) {

parentStateInfo = addState(parent, null);

}

}

StateInfo stateInfo = mStateInfo.get(state);

if (stateInfo == null) {

stateInfo = new StateInfo();

mStateInfo.put(state, stateInfo);

}

if ((stateInfo.parentStateInfo != null) && (stateInfo.parentStateInfo != parentStateInfo)) {

throw new RuntimeException("state already added");

}

stateInfo.state = state;

stateInfo.parentStateInfo = parentStateInfo;

stateInfo.active = false;

if (mDbg) Log.d(TAG, "addStateInternal: X stateInfo: " + stateInfo);

return stateInfo;

}

//获取状态机当前状态

private final IState getCurrentState() {

return mStateStack[mStateStackTopIndex].state;

}

//状态机处理消息

@Override

public final void handleMessage(Message msg) {

if (mDbg) Log.d(TAG, "handleMessage: E msg.what=" + msg.what);

mMsg = msg;

if (mIsConstructionCompleted) {

processMsg(msg);//事件处理

}

else if (!mIsConstructionCompleted &&

(mMsg.what == SM_INIT_CMD) && (mMsg.obj == mSmHandlerObj)) {

mIsConstructionCompleted = true;

invokeEnterMethods(0);

}

else {

throw new RuntimeException("StateMachine.handleMessage: " +

"The start method not called, received msg: " + msg);

}

performTransitions();//状态机切换

if (mDbg) Log.d(TAG, "handleMessage: X");

}

//状态机处理消息

private final void processMsg(Message msg) {//事件处理

StateInfo curStateInfo = mStateStack[mStateStackTopIndex];

if (mDbg) {

Log.d(TAG, "processMsg: " + curStateInfo.state.getName());

}

if (isQuit(msg)) {

transitionTo(mQuittingState);

}

else {

//状态处理，调用下面“二”中各个状态的processMessage

//当返回值为NOT_HANDLED时继续下一个，直到返回值为HANDLED

while (!curStateInfo.state.processMessage(msg)) {

curStateInfo = curStateInfo.parentStateInfo;

if (curStateInfo == null) {

mSm.unhandledMessage(msg);

break;

}

if (mDbg) {

Log.d(TAG, "processMsg: " + curStateInfo.state.getName());

}

}

if (mSm.recordLogRec(msg)) {

if (curStateInfo != null) {

State orgState = mStateStack[mStateStackTopIndex].state;

mLogRecords.add(msg, mSm.getLogRecString(msg), curStateInfo.state,

orgState);

} else {

mLogRecords.add(msg, mSm.getLogRecString(msg), null, null);

}

}

}

}

//状态机切换

private void performTransitions() {//状态机切换

State destState = null;

while (mDestState != null) {

if (mDbg) Log.d(TAG, "handleMessage: new destination call exit");

destState = mDestState;

mDestState = null;

//将transitionTo设置的状态mDestState作为下一个状态放到mStateStack中

//把当前活动state家族放入mTempStateStack中， 并且返回顶层节点的信息

StateInfo commonStateInfo = setupTempStateStackWithStatesToEnter(destState);

//从当前活动state顶层节点一次调用exit方法,并且设置state的active标记为false;

invokeExitMethods(commonStateInfo);

//将mTempStateStack的值倒序放到mStateStack中

int stateStackEnteringIndex = moveTempStateStackToStateStack();

//依次调用活动状态的enter方法，把当前state的active置为true

invokeEnterMethods(stateStackEnteringIndex);

//刷新消息队列的排序。该方法就是将 mDeferredMessages容器中的消息按先后顺序发送出去，然后清空容器。这些消息是发送给比如wifip2pservice等其他服务的

moveDeferredMessageAtFrontOfQueue();

}

if (destState != null) {

if (destState == mQuittingState) {

mSm.onQuitting();

cleanupAfterQuitting();

}

else if (destState == mHaltingState) {

mSm.onHalting();

}

}

}

}

public static class LogRec {

}

private static class LogRecords {

}

private class StateInfo {

}

private class HaltingState extends State {

}

private class QuittingState extends State {

}

}

二、相关状态分析

WifiStateMachine下有如下状态：

DefaultState、InitialState，

DriverUnloadingState、DriverUnloadedState、DriverFailedState、DriverLoadingState、DriverLoadedState，

SupplicantStartingState、SupplicantStartedState、SupplicantStoppingState，

DriverStartingState、DriverStartedState、DriverStoppingState、DriverStoppedState，

WaitForP2pDisableState、SoftApStartingState、SoftApStartedState、SoftApStoppingState、TetheringState、TetheredState，

ScanModeState、ConnectModeState、L2ConnectedState、ObtainingIpState、VerifyingLinkState、CaptivePortalCheckState、ConnectedState、DisconnectingState、DisconnectedState、WpsRunningState。

下面就其中InitialState类继承关系分析，其他相同、不再分析。

frameworks/base/wifi/java/android/net/wifi/WifiStateMachine.java

class InitialState extends State {

public void enter() {

if (DBG) log(getName() + "\n");

EventLog.writeEvent(EVENTLOG_WIFI_STATE_CHANGED, getName());

if (mWifiNative.isDriverLoaded()) {

transitionTo(mDriverLoadedState);

}

else {

transitionTo(mDriverUnloadedState);

}

mWifiP2pManager = (WifiP2pManager) mContext.getSystemService(Context.WIFI_P2P_SERVICE);

mWifiP2pChannel.connect(mContext, getHandler(), mWifiP2pManager.getMessenger());

try {

mNwService.disableIpv6(mInterfaceName);

} catch (RemoteException re) {

loge("Failed to disable IPv6: " + re);

} catch (IllegalStateException e) {

loge("Failed to disable IPv6: " + e);

}

}

}

frameworks/base/core/java/com/android/internal/util/State.java

public class State implements IState {

protected State() {

}

@Override

public void enter() {

}

@Override

public void exit() {

}

@Override

public boolean processMessage(Message msg) {

return false;

}

@Override

public String getName() {

String name = getClass().getName();

int lastDollar = name.lastIndexOf('$');

return name.substring(lastDollar + 1);

}

}