Android 5.1 Phone MO(去电)流程分析(Framework层)

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$\color{red}{本文来自}$Android 5.1 Phone MO(去电)流程分析(Framework层) $\color{red}{，转载请务必注明出处。}$

步骤1和2：紧接着应用层的流程，在$\color{red}{TelephonyConnectionService.java}$的placeOutgoingConnection方法里调用了phone.dial()，我们这里研究的是CDMA，所以下面会进入$\color{red}{CDMAPhone.java}$的dial方法：

public Connection dial (String dialString, int videoState, Bundle extras){ ... return dialInternal(dialString, null, videoState); } protected Connection dialInternal (String dialString, UUSInfo uusInfo,int videoState) throws CallStateException { // Need to make sure dialString gets parsed properly String newDialString = PhoneNumberUtils.stripSeparators(dialString); return mCT.dial(newDialString); }

步骤3和4： mCT是CdmaCallTracker类型的，所以我们进入$\color{red}{CdmaCallTracker.java}$的dial方法里：

/ * clirMode is one of the CLIR_ constants */ Connection dial (String dialString, int clirMode) throws CallStateException { // note that this triggers call state changed notif clearDisconnected(); if (!canDial()) { throw new CallStateException("cannot dial in current state"); } String origNumber = dialString; String operatorIsoContry = mPhone.getSystemProperty( TelephonyProperties.PROPERTY_OPERATOR_ISO_COUNTRY, ""); String simIsoContry = mPhone.getSystemProperty( TelephonyProperties.PROPERTY_ICC_OPERATOR_ISO_COUNTRY, ""); boolean internationalRoaming = !TextUtils.isEmpty(operatorIsoContry) && !TextUtils.isEmpty(simIsoContry) && !simIsoContry.equals(operatorIsoContry); if (internationalRoaming) { if ("us".equals(simIsoContry)) { internationalRoaming = internationalRoaming && !"vi".equals(operatorIsoContry); } else if ("vi".equals(simIsoContry)) { internationalRoaming = internationalRoaming && !"us".equals(operatorIsoContry); } } if (internationalRoaming) { dialString = convertNumberIfNecessary(mPhone, dialString); } String inEcm=SystemProperties.get(TelephonyProperties.PROPERTY_INECM_MODE, "false"); boolean isPhoneInEcmMode = inEcm.equals("true"); boolean isEmergencyCall = PhoneNumberUtils.isLocalEmergencyNumber(mPhone.getContext(), dialString); // Cancel Ecm timer if a second emergency call is originating in Ecm mode if (isPhoneInEcmMode && isEmergencyCall) { handleEcmTimer(CDMAPhone.CANCEL_ECM_TIMER); } // We are initiating a call therefore even if we previously // didn't know the state (i.e. Generic was true) we now know // and therefore can set Generic to false. mForegroundCall.setGeneric(false); // The new call must be assigned to the foreground call. // That call must be idle, so place anything that's // there on hold if (mForegroundCall.getState() == CdmaCall.State.ACTIVE) { return dialThreeWay(dialString); } mPendingMO = new CdmaConnection(mPhone.getContext(), checkForTestEmergencyNumber(dialString), this, mForegroundCall); mHangupPendingMO = false; if ( mPendingMO.getAddress() == null || mPendingMO.getAddress().length() == 0 || mPendingMO.getAddress().indexOf(PhoneNumberUtils.WILD) >= 0 ) { // Phone number is invalid mPendingMO.mCause = DisconnectCause.INVALID_NUMBER; // handlePollCalls() will notice this call not present // and will mark it as dropped. pollCallsWhenSafe(); } else { // Always unmute when initiating a new call setMute(false); // Check data call disableDataCallInEmergencyCall(dialString); // In Ecm mode, if another emergency call is dialed, Ecm mode will not exit. if(!isPhoneInEcmMode || (isPhoneInEcmMode && isEmergencyCall)) { mCi.dial(mPendingMO.getAddress(), clirMode, obtainCompleteMessage()); } else { mPhone.exitEmergencyCallbackMode(); mPhone.setOnEcbModeExitResponse(this,EVENT_EXIT_ECM_RESPONSE_CDMA, null); mPendingCallClirMode=clirMode; mPendingCallInEcm=true; } } if (mNumberConverted) { mPendingMO.setConverted(origNumber); mNumberConverted = false; } //更新phone状态 updatePhoneState(); //发起phone状态变化通知 mPhone.notifyPreciseCallStateChanged(); //返回通话连接 return mPendingMO; } / * Obtain a message to use for signalling "invoke getCurrentCalls() when * this operation and all other pending operations are complete */ private Message obtainCompleteMessage() { return obtainCompleteMessage(EVENT_OPERATION_COMPLETE); } / * Obtain a message to use for signalling "invoke getCurrentCalls() when * this operation and all other pending operations are complete */ private Message obtainCompleteMessage(int what) { mPendingOperations++; mLastRelevantPoll = null; mNeedsPoll = true; if (DBG_POLL) log("obtainCompleteMessage: pendingOperations=" + mPendingOperations + ", needsPoll=" + mNeedsPoll); return obtainMessage(what); }

步骤5：先看$\color{red}{obtainCompleteMessage}$方法，这里调用obtainCompleteMessage带一个参数的方法创建了一个消息类型为EVENT_OPERATION_COMPLETE的Message，这个Message也会传入到mCi.dial方法里，在这里是CdmaCallTracker主动向RILJ（mCi是RILJ的实例对象，后面再解释为什么）发送消息，等RILJ处理完之后通过回调通知CdmaCallTracker，CdmaCallTracker就在handleMessage方法处理。

知识点解析：至于$\color{red}{mCi是什么？}$，它是CommandsInterface类型的，在CdmaCallTracker的构造方法里通过mCi = phone.mCi;获取：

public CdmaCallTracker(CDMAPhone phone) { ... mCi = phone.mCi; ... }

phone是CDMAPhone类型的，在CDMAPhone的构造方法里并没有关于mCi的定义和创建代码，只有super这一行有联系

public CDMAPhone(Context context, CommandsInterface ci, PhoneNotifier notifier, boolean unitTestMode) { super("CDMA", notifier, context, ci, unitTestMode); ... }

我们再进入CDMAPhone的父类PhoneBase的构造方法里，

protected PhoneBase(String name, PhoneNotifier notifier, Context context, CommandsInterface ci,boolean unitTestMode) { ... mCi = ci; ... } 

找到mCi的定义和初始化信息：mCi = ci;ci是在CDMAPhone的构造方法里的传递对象，因此，如果找到CDMAPhone创建phone对象的地方，也许可以找到ci的创建。
我们要找CDMAPhone被调用的地方，（在Source Insight这个编译器中，选中CDMAPhone，然后按快捷键Ctrl+/），我们找到$\color{red}{PhoneFactory.java}$的makeDefaultPhone方法里：

 public static void makeDefaultPhone(Context context) { ... sCommandsInterface = new RIL(context, networkMode, cdmaSubscription); UiccController.make(context, sCommandsInterface); int phoneType = TelephonyManager.getPhoneType(networkMode); if (phoneType == PhoneConstants.PHONE_TYPE_GSM) { Rlog.i(LOG_TAG, "Creating GSMPhone"); sProxyPhone = new PhoneProxy( new GSMPhone(context,sCommandsInterface, sPhoneNotifier)); } } 

在创建Phone对象时，传入RILJ类型的sCommandsInterface对象作为参数，因此，我们可以确定CdmaCallTracker.java中使用mCi.dial进行拨号，其实就是调用了$\color{red}{RIL.java}$的dial方法。

步骤6： $\color{red}{RIL.java}$的dial方法

public void dial(String address, int clirMode, UUSInfo uusInfo, Message result) { RILRequest rr = RILRequest.obtain(RIL_REQUEST_DIAL, result); rr.mParcel.writeString(address); rr.mParcel.writeInt(clirMode); if (uusInfo == null) { rr.mParcel.writeInt(0); // UUS information is absent } else { rr.mParcel.writeInt(1); // UUS information is present rr.mParcel.writeInt(uusInfo.getType()); rr.mParcel.writeInt(uusInfo.getDcs());  rr.mParcel.writeByteArray(uusInfo.getUserData()); } //打印日志 if (RILJ_LOGD) riljLog(rr.serialString() + "> " + requestToString(rr.mRequest)); send(rr);  }

打印出来的log：

08-11 09:39:24.313 D/RILJ ( 2904): [5503]> DIAL

在这里创建了RILRequest 对象rr，将CdmaCallTracker传递过来的消息类型为EVENT_OPERATION_COMPLETE的Message赋值给rr.mResult，然后RILJ向RILD发送了RIL_REQUEST_DIAL请求。
步骤7：等底层处理完之后，会发送RIL_REQUEST_DIAL消息给RILJ，在RILJ的$\color{red}{processSolicited}$方法里接收并处理该消息：

private RILRequest processSolicited (Parcel p) { ... case RIL_REQUEST_DIAL: ret = responseVoid(p); break; ... //打印log日志 if (RILJ_LOGD) riljLog(rr.serialString() + "< " + requestToString(rr.mRequest) + " " + retToString(rr.mRequest, ret)); if (rr.mResult != null) { AsyncResult.forMessage(rr.mResult, null, tr); rr.mResult.sendToTarget();//发出handler消息通知 }

步骤8，9，10： $\color{red}{rr.mResult}$就是在CdmaCallTracker中创建的消息类型为EVENT_OPERATION_COMPLETE的Message，所以调用sendToTarget方法，就会把消息发送给CdmaCallTracker，然后在$\color{red}{CdmaCallTracker.java}$的handleMessage方法中有对EVENT_OPERATION_COMPLETE的逻辑处理：

public void handleMessage (Message msg) { ... switch (msg.what) { case EVENT_OPERATION_COMPLETE: operationComplete(); break; ... } private void operationComplete() { mPendingOperations--; if (DBG_POLL) log("operationComplete: pendingOperations=" + mPendingOperations + ", needsPoll=" + mNeedsPoll); if (mPendingOperations == 0 && mNeedsPoll) { mLastRelevantPoll = obtainMessage(EVENT_POLL_CALLS_RESULT); mCi.getCurrentCalls(mLastRelevantPoll); } else if (mPendingOperations < 0) { // this should never happen Rlog.e(LOG_TAG,"CdmaCallTracker.pendingOperations < 0"); mPendingOperations = 0; } }

步骤11和12：在这里通过$\color{red}{obtainMessage}$方法生成一个消息类型为EVENT_POLL_CALLS_RESULT的Message并且作为getCurrentCalls方法的参数传递到mCi，mCi是RIL.java的实例对象，这也就回到了$\color{red}{RIL.java}$的getCurrentCalls方法里，getCurrentCalls将RIL_REQUEST_GET_CURRENT_CALLS 消息封装成RILRequest 类型并发送。

public void getCurrentCalls (Message result) { //注意rr对象的消息类型，后面会用到 RILRequest rr = RILRequest.obtain( RIL_REQUEST_GET_CURRENT_CALLS, result); //打印log日志 if (RILJ_LOGD) riljLog(rr.serialString() + "> " + requestToString(rr.mRequest)); send(rr); }

打印出相应的log是

09-09 17:32:02.179 D/RILJ ( 2795): [5656]> GET_CURRENT_CALLS

步骤13： RILJ向底层请求查询Call List状态列表，等底层处理完之后，就把结果返回给RILJ，向RILJ发送RIL_REQUEST_GET_CURRENT_CALLS消息，RILJ在$\color{red}{processSolicited}$方法里处理它。

private RILRequest processSolicited (Parcel p) { ... case RIL_REQUEST_GET_CURRENT_CALLS: ret = responseCallList(p); break; ... //打印log日志 if (RILJ_LOGD) riljLog(rr.serialString() + "< " + requestToString(rr.mRequest) + " " + retToString(rr.mRequest, ret)); if (rr.mResult != null) { AsyncResult.forMessage(rr.mResult, null, tr); rr.mResult.sendToTarget();//发出handler消息通知 }

步骤14和15：还是跟上面一样，$\color{red}{rr.mResult}$就是刚刚在CdmaCallTracker中创建的那个消息类型为EVENT_POLL_CALLS_RESULT的Message，所以在$\color{red}{CdmaCallTracker.java}$的handleMessage 方法中会有EVENT_POLL_CALLS_RESULT的逻辑处理

public void handleMessage (Message msg) { ... switch (msg.what) { case EVENT_POLL_CALLS_RESULT:{ //打印log日志 Rlog.d(LOG_TAG, "Event EVENT_POLL_CALLS_RESULT Received"); ar = (AsyncResult)msg.obj; if(msg == mLastRelevantPoll) { if(DBG_POLL) log( "handle EVENT_POLL_CALL_RESULT: set needsPoll=F"); mNeedsPoll = false; mLastRelevantPoll = null; handlePollCalls((AsyncResult)msg.obj); } } break; ... }

步骤16：最后，会进入$\color{red}{handlePollCalls}$方法，关于handlePollCalls方法，《handlePollCalls方法详解》这篇文章讲得比较详细，对于我们这里，是打电话流程中，第一次查询Call List列表，所以会进入这里：

//conn代表旧的通话连接的基本信息，dc代表新的。出现新的通话连接 if (conn == null && dc != null) { //主动发起拨号请求后，第一次查询到Call List后，进入这里 // Connection appeared in CLCC response that we don't know about if (mPendingMO != null && mPendingMO.compareTo(dc)) { if (DBG_POLL) log("poll: pendingMO=" + mPendingMO); // It's our pending mobile originating call mConnections[i] = mPendingMO; //把i的值赋值给index mPendingMO.mIndex = i; mPendingMO.update(dc); mPendingMO = null; // Someone has already asked to hangup this call if (mHangupPendingMO) { mHangupPendingMO = false; // Re-start Ecm timer when an uncompleted emergency call ends if (mIsEcmTimerCanceled) { handleEcmTimer(CDMAPhone.RESTART_ECM_TIMER); } try { if (Phone.DEBUG_PHONE) log( "poll: hangupPendingMO, hangup conn " + i); hangup(mConnections[i]); } catch (CallStateException ex) { Rlog.e(LOG_TAG, "unexpected error on hangup"); } // Do not continue processing this poll // Wait for hangup and repoll return; } } 

好像也没有多大作用，就是把mPendingMO的值赋值给mConnections和把i的值赋值给mIndex 。

步骤17和18：接着，底层又会上报RIL_UNSOL_RESPONSE_CALL_STATE_CHANGED消息给RILJ，这是底层主动上报的消息，所以RILJ会在$\color{red}{processUnsolicited}$方法里进行处理

private void processUnsolicited (Parcel p) { ... try { 
  switch(response) { ... case RIL_UNSOL_RESPONSE_CALL_STATE_CHANGED: ret = responseVoid(p); break; ... } switch(response) { ... case RIL_UNSOL_RESPONSE_CALL_STATE_CHANGED: if (RILJ_LOGD) unsljLog(response);//打印log日志 //发出通知（RegistrantList消息处理机制） mCallStateRegistrants.notifyRegistrants(new AsyncResult(null, null, null)); ... } }

（在Source Insight这个编译器中，选中mCallStateRegistrants，然后按快捷键Ctrl+/），我们找到BaseCommands.java的registerForCallStateChanged方法，接着继续找它的调用者，最后我们来到CdmaCallTracker.java的构造方法里

public CdmaCallTracker(CDMAPhone phone) { ... mCi.registerForCallStateChanged(this, EVENT_CALL_STATE_CHANGE, null); ... }

发觉是CdmaCallTracker.java向RIL注册了一个EVENT_CALL_STATE_CHANGE类型的Handler消息。
步骤19，20，21：因此，我们在$\color{red}{CdmaCallTracker.java}$的handleMessage方法里可以找到响应EVENT_CALL_STATE_CHANGE消息类型的处理逻辑，如下：

 public void handleMessage (Message msg) { ... case EVENT_CALL_STATE_CHANGE: //调用父类CallTracker查询Call List方法 pollCallsWhenSafe(); break; ... } protected void pollCallsWhenSafe() { ... if (checkNoOperationsPending()) { //注意mLastRelevantPoll对象的消息类型，后面会用到 mLastRelevantPoll = obtainMessage(EVENT_POLL_CALLS_RESULT); mCi.getCurrentCalls(mLastRelevantPoll); } }

步骤22和23：又是RILJ请求查询Call List状态列表。。。老样子，查完还是交给 CdmaCallTracker去处理。这时候Call的状态还是DIALING。
步骤24~27：等Call的状态变成ACTIVE后，底层又会上报RIL_UNSOL_RESPONSE_CALL_STATE_CHANGED消息给RILJ，然后RILJ又请求查询查询Call List状态列表，CdmaCallTracker又处理。。。
到这里，电话已接通，打电话的流程就这么多了。

下面贴出打电话流程的log片段

09-09 17:32:01.730 D/RILJ ( 2795): [5655]> DIAL 09-09 17:32:01.810 D/RILJ ( 2795): [5655]< DIAL 09-09 17:32:01.935 D/RILJ ( 2795): [UNSL]< UNSOL_RESPONSE_CALL_STATE_CHANGED 09-09 17:32:02.179 D/RILJ ( 2795): [5656]> GET_CURRENT_CALLS 09-09 17:32:02.183 V/RILJ ( 2795): Incoming UUS : NOT present! 09-09 17:32:02.183 D/RILJ ( 2795): InCall VoicePrivacy is disabled 09-09 17:32:02.183 D/RILJ ( 2795): [5656]< GET_CURRENT_CALLS [id=1,DIALING,toa=129,norm,mo,0,voc,noevp,,cli=1,,0] 09-09 17:32:02.196 D/RILJ ( 2795): [5657]> GET_CURRENT_CALLS 09-09 17:32:02.201 V/RILJ ( 2795): Incoming UUS : NOT present! 09-09 17:32:02.201 D/RILJ ( 2795): InCall VoicePrivacy is disabled 09-09 17:32:02.201 D/RILJ ( 2795): [5657]< GET_CURRENT_CALLS [id=1,DIALING,toa=129,norm,mo,0,voc,noevp,,cli=1,,0] 09-09 17:32:02.306 D/CdmaCallTracker( 2795): Event EVENT_POLL_CALLS_RESULT Received 09-09 17:32:02.306 D/CdmaCallTracker( 2795): Event EVENT_POLL_CALLS_RESULT Received 09-09 17:32:03.607 D/RILJ ( 2795): [UNSL]< UNSOL_RESPONSE_CALL_STATE_CHANGED 09-09 17:32:03.686 D/RILJ ( 2795): [5658]> GET_CURRENT_CALLS 09-09 17:32:03.688 D/RILJ ( 2795): [5659]> GET_CURRENT_CALLS 09-09 17:32:03.691 D/RilRequest( 2795): [5659]< GET_CURRENT_CALLS error: com.android.internal.telephony.CommandException: GENERIC_FAILURE ret= 09-09 17:32:03.696 D/RILJ ( 2795): [5658]< GET_CURRENT_CALLS [id=1,ACTIVE,toa=129,norm,mo,0,voc,noevp,,cli=1,,0] 09-09 17:32:03.745 D/CdmaCallTracker( 2795): Event EVENT_POLL_CALLS_RESULT Received 09-09 17:32:03.745 D/CdmaCallTracker( 2795): Event EVENT_POLL_CALLS_RESULT Received 09-09 17:32:03.995 D/RILJ ( 2795): [5660]> GET_CURRENT_CALLS 09-09 17:32:04.002 D/RILJ ( 2795): [5660]< GET_CURRENT_CALLS [id=1,ACTIVE,toa=129,norm,mo,0,voc,noevp,,cli=1,,0] 09-09 17:32:04.002 D/CdmaCallTracker( 2795): Event EVENT_POLL_CALLS_RESULT Received 09-09 17:32:04.004 D/CallStateMonitor( 2795): handleMessage(10) 09-09 17:32:04.004 D/CallNotifier( 2795): PHONE_ENHANCED_VP_OFF... 09-09 17:32:04.005 D/CallStateMonitor( 2795): handleMessage(1)