android 系统上做GC双模的---数据业务的处理分析

一：modem相关的各种状态的监听和通知机制／通话相关的图标变换的工作原理。

网络状态，evdo,图标的处理

a、注册监听部分

==>SystemServer.java

 init2()

   Thread thr = new ServerThread();

   thr.setName("android.server.ServerThread");

   thr.start();

     ServerThread.run()

       com.android.server.status.StatusBarPolicy.installIcons(context,statusBar);

         sInstance = new StatusBarPolicy(context, service);

           // phone_signal

           mPhone = (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE);

           mPhoneData = IconData.makeIcon("phone_signal",

               null,com.android.internal.R.drawable.stat_sys_signal_null, 0, 0);

           mPhoneIcon = service.addIcon(mPhoneData, null);

            // register for phone state notifications.

           ((TelephonyManager)mContext.getSystemService(Context.TELEPHONY_SERVICE))

                .listen(mPhoneStateListener,

                         PhoneStateListener.LISTEN_SERVICE_STATE

                        |PhoneStateListener.LISTEN_SIGNAL_STRENGTH

                        |PhoneStateListener.LISTEN_CALL_STATE

                        |PhoneStateListener.LISTEN_DATA_CONNECTION_STATE

                        |PhoneStateListener.LISTEN_DATA_ACTIVITY);

            //实际是调用的是TelephonyRegistry.listen，此listen函数会将Iphonestatelistener添加到对应的的handler数组中，到时来了事件会轮询回调。

           // data_connection

           mDataData = IconData.makeIcon("data_connection",

                null, com.android.internal.R.drawable.stat_sys_data_connected_g,0, 0);

           mDataIcon = service.addIcon(mDataData, null);

           service.setIconVisibility(mDataIcon, false);

b、事件通知部分

==>PhoneFactory.java

makeDefaultPhones()

 sPhoneNotifier = new DefaultPhoneNotifier();

 useNewRIL(context);

   phone = new GSMPhone(context, new RIL(context), sPhoneNotifier);

for example

==>DataConnectionTracker.java

notifyDefaultData(String reason)

 phone.notifyDataConnection(reason);

   mNotifier.notifyDataConnection(this, reason);

   ==>DefaultPhoneNotifier.java

     mRegistry =ITelephonyRegistry.Stub.asInterface(ServiceManager.getService(

                   "telephony.registry"));

     mRegistry.notifyDataConnection(convertDataState(sender.getDataConnectionState()),

                   sender.isDataConnectivityPossible(),reason, sender.getActiveApn(),

                   sender.getInterfaceName(null));

 

二 CDMA EVDO拨号上网的通路原理。

上层java程序调用gprs流程：

=>PhoneApp.java

 onCreate()

   PhoneFactory.makeDefaultPhones(this);

     phone = new GSMPhone(context, new SimulatedCommands(), sPhoneNotifier);

       mDataConnection = new DataConnectionTracker (this);

         createAllPdpList();//建立缺省pdpconnection

            pdp = new PdpConnection(phone);

               dataLink = newPppLink(phone.mDataConnection);

               dataLink.setOnLinkChange(this,EVENT_LINK_STATE_CHANGED, null);

       

         //某个条件触发执行

         trySetupData(String reason)

          setupData(reason);

            pdp = findFreePdp();

            Message msg =obtainMessage();

            msg.what = EVENT_DATA_SETUP_COMPLETE;

            msg.obj = reason;

            pdp.connect(apn, msg);

                        phone.mCM.setupDefaultPDP(apn.apn, apn.user, apn.password,

                            obtainMessage(EVENT_SETUP_PDP_DONE));

        

          //收到EVENT_SETUP_PDP_DONE消息

          =>pdpconnection.java

          handleMessage()

            case EVENT_SETUP_PDP_DONE:

               dataLink.connect();//dataLink是pppLink.java

                  SystemService.start(SERVICE_PPPD_GPRS);//启动pppd_grps服务

                  poll.what =EVENT_POLL_DATA_CONNECTION;

                  sendMessageDelayed(poll,POLL_SYSFS_MILLIS);//启动轮询，看是否成功连接gprs

                    checkPPP()//每隔5秒轮询，看是否连接成功，或断开

                      //如果已经连接

                     mLinkChangeRegistrant.notifyResult(LinkState.LINK_UP);

                  //执行到pdpconnection.handleMessage()

                  case EVENT_LINK_STATE_CHANGED

                    onLinkStateChanged(ls);

                      case LINK_UP:

                       notifySuccess(onConnectCompleted);

                         onCompleted.sendToTarget();

              

                  //执行dataConnectionTracker.java的handleMessage()

                  caseEVENT_DATA_SETUP_COMPLETE

                    notifyDefaultData(reason);

                      setupDnsProperties();

                     setState(State.CONNECTED);

                      phone.notifyDataConnection(reason);

                      startNetStatPoll();

                        resetPollStats();

                        1、读取发送出去的包数和接受到的包数

                        2、如果发送的数据包且没有收到应答包数n大于等于看门狗追踪的限定包数。

                        2.1、开始轮询pdpcontext list，尝试恢复网络连接

                        2.2、如果轮询24次后还没有联通网络则停止网络状态轮询，进行一次ping实验。

                        2.2.1、如果ping成功则，重新进行网络状态轮询，否则发送EVENT_START_RECOVERY事件。

                      // reset reconnect timer

                      nextReconnectDelay =RECONNECT_DELAY_INITIAL_MILLIS;

着重c++部分代码的角度分析

＝>DataConnectionTracker.java

trySetupData(String reason)

 setupData(reason);

    ＝>PdpConnection.java

   pdp.connect(apn, msg);

     =>RIL.JAVA

     phone.mCM.setupDefaultPDP(apn.apn, apn.user, apn.password,

               obtainMessage(EVENT_SETUP_PDP_DONE));

       send(rr);

       //send socket to RIL

      

       //enter c++ layer

       =>ril.cpp

       processCommandsCallback (int fd, short flags, void *param)

         processCommandBuffer(p_record, recordlen);

           status = p.readInt32(&request);

           pRI->pCI = &(s_commands[request]);

           pRI->pCI->dispatchFunction(p, pRI);

            dispatchStrings();

              s_callbacks.onRequest(pRI->pCI->requestNumber, pStrings, datalen,pRI);

               =>reference-ril.c

                 onRequest();

                   requestSetupDefaultPDP(data,datalen, t);

                     err =write_at_to_data_channel("ATD*99***1#",1);

                   

                     //after a while.get"connect" from data channel,so need to send socket message to javalayer.

                     p.writeInt32(RESPONSE_SOLICITED);

                     p.writeInt32(pRI->token);//the serial No  in therequest list.

                     errorOffset =p.dataPosition();

                     p.writeInt32 (e);

                     if (e == RIL_E_SUCCESS) {

                        /* process response onsuccess */

                        ret =pRI->pCI->responseFunction(p, response, responselen);

                        /* if an erroroccurred, rewind and mark it */

                        if (ret != 0) {

                         p.setDataPosition(errorOffset);

                          p.writeInt32 (ret);

                        }

                     }

                     sendResponse(p);

                     sendResponseRaw(p.data(),p.dataSize());

                       ret = blockingWrite(fd,(void *)&header, sizeof(header));

                       blockingWrite(fd, data,dataSize);

                     

                       =>RIL.JAVA

                       RILReceiver.run();

                         length =readRilMessage(is, buffer);

                         p = Parcel.obtain();

                         p.unmarshall(buffer,0, length);

                         p.setDataPosition(0);

                         processResponse(p);

                           processSolicited(p);

                             serial =p.readInt();

                             error =p.readInt();

                             rr =findAndRemoveRequestFromList(serial);

                             ret =  responseStrings(p);

                             if (rr.mResult !=null) {

                               AsyncResult.forMessage(rr.mResult,ret, null);

                              rr.mResult.sendToTarget();

                             }

        

      =>pdpConnection.java

      handleMessage()

        case EVENT_SETUP_PDP_DONE:

           ...

           dataLink.connect();

           =>pppLink.java

             SystemProperties.set(PROPERTY_PPPD_EXIT_CODE, "");

             SystemService.start(SERVICE_PPPD_GPRS);//启动pppd_grps服务

             poll.what =EVENT_POLL_DATA_CONNECTION;

              sendMessageDelayed(poll,POLL_SYSFS_MILLIS);

              dataConnection.state =State.CONNECTING;

              handleMessage()

                case EVENT_POLL_DATA_CONNECTION

                  checkPPP();

                    if(ArrayUtils.equals(mCheckPPPBuffer, UP_ASCII_STRING, UP_ASCII_STRING.length)

                    ||ArrayUtils.equals(mCheckPPPBuffer, UNKNOWN_ASCII_STRING,

                           UNKNOWN_ASCII_STRING.length)

                           &&dataConnection.state == State.CONNECTING)

                    if (mLinkChangeRegistrant!= null) {

                     mLinkChangeRegistrant.notifyResult(LinkState.LINK_UP);

                  =>pdpConnection.java

                  handleMessage()

                    caseEVENT_LINK_STATE_CHANGED:

                      DataLink.LinkStatels  = (DataLink.LinkState) ar.result;

                      onLinkStateChanged(ls);

                        case LINK_UP:

                           notifySuccess(onConnectCompleted);

                            AsyncResult.forMessage(onCompleted);

                            onCompleted.sendToTarget();

                           

                            =>DataConnectionTracker.java

                             handleMessage()

                               caseEVENT_DATA_SETUP_COMPLETE:

                               ...

                                SystemProperties.set("gsm.defaultpdpcontext.active","true");

                                 notifyDefaultData(reason);

                                  setupDnsProperties();//设置dns，gw，我们的实现方式是在pppd中设置的，不用pppd拨号的适用。

                                  setState(State.CONNECTED);

                                  phone.notifyDataConnection(reason);

                                      mNotifier.notifyDataConnection(this, reason);

                                       ＝>DefaultPhoneNotifier.java

                                         //mRegistry = ITelephonyRegistry.Stub.asInterface(ServiceManager.getService(

                   "telephony.registry"));构造函数中初始化了mRegistry

                                         mRegistry.notifyDataConnection(convertDataState(sender.getDataConnectionState()),

                                              sender.isDataConnectivityPossible(),reason, sender.getActiveApn(),

                                             sender.getInterfaceName(null));

                                 startNetStatPoll();   

                }