作为Phone重要的Tracker：CallTracker，DataConnectionTracker，ServiceStateTracker

ServiceStateTracker：处理和维护手机各种状态

                   小区位置CellLocation，网络状态ServiceState，信号强度SignalStrength，

                   业务限制状态RestrictedState，用户识别卡信息IccRecords……

看一下ServiceStateTracker类结构图：

　　　　        

对于CDMA和GSM两种网络通信技术，存在着一些差异，下面看看CDMAServiceStateTracker工作流程。

         CDMAServiceStateTracker是一个Handler，用来处理很多Message，从其处理的Message上就可以了解CDMAServiceStateTracker流程和作用。

1 CDMAServiceStateTracker构造

public CdmaServiceStateTracker(CDMAPhone phone) {
        //相关对象初始化
        this.phone = phone;
        ss = new ServiceState();
        newSS = new ServiceState();
        cellLoc = new CdmaCellLocation();
        mSignalStrength = new SignalStrength();
        
        //CDMA Subscription Source 管理 机卡分离 Or 机卡一体
        mCdmaSSM = CdmaSubscriptionSourceManager.getInstance(phone.getContext(), cm, this,
                EVENT_CDMA_SUBSCRIPTION_SOURCE_CHANGED, null);

        //向RIL注册相关的事件
        //注册Radio 状态变化监听事件
        cm.registerForRadioStateChanged(this, EVENT_RADIO_STATE_CHANGED, null);

        //语音业务状态变化
        cm.registerForVoiceNetworkStateChanged(this, EVENT_NETWORK_STATE_CHANGED_CDMA, null);

        //时间更新
        cm.setOnNITZTime(this, EVENT_NITZ_TIME, null);

        //信号强度更新
        cm.setOnSignalStrengthUpdate(this, EVENT_SIGNAL_STRENGTH_UPDATE, null);

        //漫游列表相关
        cm.registerForCdmaPrlChanged(this, EVENT_CDMA_PRL_VERSION_CHANGED, null);

        //OTA相关
        cm.registerForCdmaOtaProvision(this,EVENT_OTA_PROVISION_STATUS_CHANGE, null);

        //获取CDMA制式
        cm.getCDMASubscription(obtainMessage(EVENT_POLL_STATE_CDMA_SUBSCRIPTION));

        // System setting property AIRPLANE_MODE_ON is set in Settings.
        int airplaneMode = Settings.System.getInt(cr, Settings.System.AIRPLANE_MODE_ON, 0);
        mDesiredPowerState = ! (airplaneMode > 0);
}

2 事件处理

RIL接收到此类事件就会notify到注册的Handler中处理；

public void handleMessage (Message msg) {
        switch (msg.what) {
                ……
            case EVENT_RUIM_READY:
                //解析漫游相关的ERI数据
                phone.prepareEri();
                break;
            case EVENT_NV_READY:
                //机卡一体subscription information存储在手机上NV中
                getSubscriptionInfoAndStartPollingThreads();
                break;
            case EVENT_RADIO_STATE_CHANGED:
                //Radio打开状态 获取信号强度
                if(cm.getRadioState() == RadioState.RADIO_ON) {
                    handleCdmaSubscriptionSource(mCdmaSSM.getCdmaSubscriptionSource());
                    // Signal strength polling stops when radio is off.
                    queueNextSignalStrengthPoll();
                }
                //start Radio
                setPowerStateToDesired();
                //网络状态变化更新
                pollState();
                break;
            case EVENT_NETWORK_STATE_CHANGED_CDMA:
                //网络状态变化更新
                pollState();
                break;
            case EVENT_GET_SIGNAL_STRENGTH:
                //获取射频信号强度
                onSignalStrengthResult(ar, phone, false);
                queueNextSignalStrengthPoll();
                break;
            case EVENT_POLL_SIGNAL_STRENGTH:
                cm.getSignalStrength(obtainMessage(EVENT_GET_SIGNAL_STRENGTH));
                break;

            case EVENT_NITZ_TIME:
                //更新时间
                setTimeFromNITZString(nitzString, nitzReceiveTime);
                break;
            case EVENT_SIGNAL_STRENGTH_UPDATE:
                //更新信号强度
                onSignalStrengthResult(ar, phone, false);
                break;
            case EVENT_RUIM_RECORDS_LOADED:
                //更新手机Spn显示
                updateSpnDisplay();
                break;
            ……
        }
    }

3 事件处理流程

                   开机构造Phone时，创建CdmaServiceStateTracker对象并注册监听事件.

开机几个事件处理：

  　　　　　　　　

　　rild进程中建立RIL CPP与QCRIL的连接之后，要保证建立Framework层RIL与Native RIL socket连接

当建立socket连接之后，RIL_CPP会想 RIL_JAVA发送RIL_UNSOL_RIL_CONNECTED消息，告诉RIL_JAVA已经建立连接;

　　否则RIL_JAVA不断尝试建立连接，RIL_CPP会继续监听连接.

根据这个序列图过程：

　　1)  RIL_CPP向RIL_JAVA发送建立连接消息RIL_UNSOL_RIL_CONNECTED

　　2) RIL_JAVA收到建立连接的RIL_UNSOL_RIL_CONNECTED后，向RILD发送RIL_REQUEST_RADIO_POWER消息，将RADIO置为 OFF状态

　　3)  MODEM发送RADIO状态改变的事件，RIL_JAVA收到后，切换状态并通知RADIO状态变化

　　4)  CdmaServiceStateTracker接收到EVENT_RADIO_STATE_CHANGED通知，会启动RADIO设置为On状态

　　5)  RIL_JAVA会向RILD发送RIL_REQUEST_RADIO_POWER消息，去启动RADIO

　　6)  RADIO状态变化，发送EVENT_RADIO_STATE_CHANGED通知，CdmaServiceStateTracker更新状态，获取信号强度……

4  状态设置

         在代码里看到状态的变化处理都是在pollState中处理的

　　case EVENT_RADIO_STATE_CHANGED:
            setPowerStateToDesired();
            pollState();
            break;
   case EVENT_NETWORK_STATE_CHANGED_CDMA:
            pollState();
            break;

最终状态的都是通过调用函数pollStateDone完成：

　　protected void pollStateDone() {
            //维护两个ServiceState状态，判断状态的变化状况
        if (DBG) log("pollStateDone: oldSS=[" + ss + "] newSS=[" + newSS + "]");
        
           //移动网络状况
        boolean hasRegistered =
            ss.getState() != ServiceState.STATE_IN_SERVICE
            && newSS.getState() == ServiceState.STATE_IN_SERVICE;

        boolean hasDeregistered =
            ss.getState() == ServiceState.STATE_IN_SERVICE
            && newSS.getState() != ServiceState.STATE_IN_SERVICE;
        
           //数据网络状况
        boolean hasCdmaDataConnectionAttached =
            mDataConnectionState != ServiceState.STATE_IN_SERVICE
            && mNewDataConnectionState == ServiceState.STATE_IN_SERVICE;
        boolean hasCdmaDataConnectionDetached =
            mDataConnectionState == ServiceState.STATE_IN_SERVICE
            && mNewDataConnectionState != ServiceState.STATE_IN_SERVICE;
        
           //各种数据连接状态变化判断
        boolean hasCdmaDataConnectionChanged =
                       mDataConnectionState != mNewDataConnectionState;

        boolean hasRadioTechnologyChanged = mRilRadioTechnology != mNewRilRadioTechnology;

        boolean hasChanged = !newSS.equals(ss);

        boolean hasRoamingOn = !ss.getRoaming() && newSS.getRoaming();

        boolean hasRoamingOff = ss.getRoaming() && !newSS.getRoaming();

        boolean hasLocationChanged = !newCellLoc.equals(cellLoc);

        
            //更新状态
        ServiceState tss;
        tss = ss;
        ss = newSS;
        newSS = tss;
        // clean slate for next time
        newSS.setStateOutOfService();

        CdmaCellLocation tcl = cellLoc;
        cellLoc = newCellLoc;
        newCellLoc = tcl;

        mDataConnectionState = mNewDataConnectionState;
        mRilRadioTechnology = mNewRilRadioTechnology;
        // this new state has been applied - forget it until we get a new new state
        mNewRilRadioTechnology = 0;
        newSS.setStateOutOfService(); // clean slate for next time
        
        
            //网络注册状态通知
        if (hasRegistered) {
            mNetworkAttachedRegistrants.notifyRegistrants();
        }

        //数据连接通知
        if (hasCdmaDataConnectionAttached) {
            mAttachedRegistrants.notifyRegistrants();
        }
            //数据断开通知
        if (hasCdmaDataConnectionDetached) {
            mDetachedRegistrants.notifyRegistrants();
        }

            //开启漫游通知
        if (hasRoamingOn) {
            mRoamingOnRegistrants.notifyRegistrants();
        }
        
            ……
    }