android wifi打开进程源码解析及Wifi打开失败原因分析

android wifi打开过程源码解析及Wifi打开失败原因分析

  在android中wifi打开的状态从DISABLED-->ENABLING-->ENABLED

  1 WifiSettings.java--wifi界面wifi开关

  wifi开关定义在SettingsActivity.java中，传入WifiEnabler.java，并在WifiEnabler.java中响应。 

  private SwitchBar mSwitchBar;  public SwitchBar getSwitchBar() {      return mSwitchBar;  }  mSwitchBar = (SwitchBar) findViewById(R.id.switch_bar);

  private SwitchBar mSwitchBar;  public SwitchBar getSwitchBar() {      return mSwitchBar;  }  mSwitchBar = (SwitchBar) findViewById(R.id.switch_bar);

  2 WifiEnabler.java--响应点击wifi开关

  WifiEnabler.java实际处理开关wifi的消息。

  @Override  public void onSwitchChanged(Switch switchView, boolean isChecked) {       Log.d(TAG, "mWifiManager.setWifiEnabled");      if (!mWifiManager.setWifiEnabled(isChecked)) {          // Error          Log.d(TAG, "set wifi enabled error");          mSwitchBar.setEnabled(true);          Toast.makeText(mContext, R.string.wifi_error, Toast.LENGTH_SHORT).show();      }    }

3 WifiManager.java和WifiService.java

  WifiEnabler.java调用WifiManager，WifiManager调用WifiService. 

  mService.setWifiEnabled(enabled);    

  public synchronized boolean setWifiEnabled(boolean enable) {               Slog.d(TAG, "setWifiEnabled: " + enable + " pid=" + Binder.getCallingPid()                    + ", uid=" + Binder.getCallingUid());        if (DBG) {            Slog.e(TAG, "Invoking mWifiStateMachine.setWifiEnabled\n");        }                if (!mIsControllerStarted) {            Slog.e(TAG,"WifiController is not yet started, abort setWifiEnabled");            return false;        }        mWifiController.sendMessage(CMD_WIFI_TOGGLED);        return true;    }

4 WifiController.java

  WifiController.java处理开关wifi 的消息CMD_WIFI_TOGGLED，从ApStaDisabledState-->StaEnabledState-->DeviceActiveState，

 class ApStaDisabledState extends State {     @Override     public boolean processMessage(Message msg) {         switch (msg.what) {             case CMD_WIFI_TOGGLED:             case CMD_AIRPLANE_TOGGLED:                 if (mSettingsStore.isWifiToggleEnabled()) {                     if (doDeferEnable(msg)) {                         if (mHaveDeferredEnable) {                             //  have 2 toggles now, inc serial number an ignore both                             mDeferredEnableSerialNumber++;                         }                         mHaveDeferredEnable = !mHaveDeferredEnable;                         break;                     }                     if (mDeviceIdle == false) {                         transitionTo(mDeviceActiveState);                     } else {                         checkLocksAndTransitionWhenDeviceIdle();                     }                 } else if (mSettingsStore.isScanAlwaysAvailable()) {                     transitionTo(mStaDisabledWithScanState);                 }                 break; } 

 class StaEnabledState extends State {     @Override     public void enter() {         mWifiStateMachine.setSupplicantRunning(true);     } } 

在进入StaEnabledState时由WifiStateMachine启动supplicant，进入DeviceActiveState时启动driver。

 /* Parent: StaEnabledState */ class DeviceActiveState extends State {     @Override     public void enter() {         mWifiStateMachine.setOperationalMode(WifiStateMachine.CONNECT_MODE);         mWifiStateMachine.setDriverStart(true);         mWifiStateMachine.setHighPerfModeEnabled(false);     } } 

5 WifiStateMachine.java

  WIFI_STATE_ENABLED由SupplicantStartingState发出，   CMD_START_SUPPLICANT-->startMonitoring-->WifiMonitor.SUP_CONNECTION_EVENT-->WifiManager.WIFI_STATE_ENABLED，到此wifi开关完全打开。

 class InitialState extends State {             @Override     public boolean processMessage(Message message) {                     switch (message.what) {             case CMD_START_SUPPLICANT:                 if (mWifiNative.loadDriver()) {                                          mNwService.wifiFirmwareReload(mInterfaceName, "STA");                                             if(mWifiNative.startSupplicant(mP2pSupported)) {                         setWifiState(WIFI_STATE_ENABLING);                                                     mWifiMonitor.startMonitoring();                         transitionTo(mSupplicantStartingState);                     }                  }                  break;     } }

 class SupplicantStartingState extends State {      @Override     public boolean processMessage(Message message) {                    switch(message.what) {             case WifiMonitor.SUP_CONNECTION_EVENT:                 if (DBG) log("Supplicant connection established");                 setWifiState(WIFI_STATE_ENABLED);
                 transitionTo(mDriverStartedState);                 break;     } }

6  SoftAP打开失败wifi不能打开原因分析

  SoftAP打开过程：

  WifiService的setWifiApEnabled-->WifiController的CDM_SET_AP-->WifiStateMachine的CMD_START_AP 

 class SoftApStartingState extends State {     @Override     public void enter() {                     if (message.what == CMD_START_AP) {             final WifiConfiguration config = (WifiConfiguration) message.obj;             if (config == null) {                 mWifiApConfigChannel.sendMessage(CMD_REQUEST_AP_CONFIG);             }          }      }     @Override     public boolean processMessage(Message message) {          switch(message.what) {                             case CMD_START_AP:                                 deferMessage(message);                 break;             case WifiStateMachine.CMD_RESPONSE_AP_CONFIG:                 WifiConfiguration config = (WifiConfiguration) message.obj;                 if (config != null) {                     startSoftApWithConfig(config);                 }                  break;                             case CMD_START_AP_FAILURE:                 setWifiApState(WIFI_AP_STATE_FAILED);                 transitionTo(mInitialState);                 break;                            }                 } }

 CMD_REQUEST_AP_CONFIG-->CMD_RESPONSE_AP_CONFIG-->startSoftApWithConfig-->CMD_START_FAILURE

 由于WifiService没有收到WIFI_AP_START_FAILED，导致WifiController处于ApEnabledState，无法接收CMD_WIFI_TOGGLED消息，从而无法进入WifiStateMachie打开WIfi。