Android通话和数据传输过程分析（转）

第三部分、第四部分：猫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，edge,gprs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));

第五部分：gprs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 = new PppLink(phone.mDataConnection);
dataLink.setOnLinkChange(this, EVENT_LINK_STATE_CHANGED, null);
dataLink = new PppLink(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()
case EVENT_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pdp context 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 java layer.
p.writeInt32 (RESPONSE_SOLICITED);
p.writeInt32 (pRI->token);//the serial No  in the request list.
errorOffset = p.dataPosition();
p.writeInt32 (e);
if (e == RIL_E_SUCCESS) {
/* process response on success */
ret = pRI->pCI->responseFunction(p, response, responselen);
/* if an error occurred, 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()
case EVENT_LINK_STATE_CHANGED:
DataLink.LinkState ls  = (DataLink.LinkState) ar.result;
onLinkStateChanged(ls);
case LINK_UP:
notifySuccess(onConnectCompleted);
AsyncResult.forMessage(onCompleted);
onCompleted.sendToTarget();

=>DataConnectionTracker.java
handleMessage()
case EVENT_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(); 
}

第六部分：通话相关的语音通路切换原理、震动接口
6、语音通路
6.1、设置语音通路的路由
目前我们有两处处理:
a、CallTracker.java中
handlePollCalls（）
检测到＋clcc返回的电话列表中有状态为DriverCall.State.ALERTING(表示拨打电话后，对方已经振铃)，此时需要设置语音通路为MODE_IN_CALL
b、PhoneUtils.java中setAudioMode（）函数
c、调用通路分析
AudioManager audioManager = (AudioManager) context.getSystemService
(Context.AUDIO_SERVICE);
audioManager.setMode(mode);

AudioManager.setMode(mode);
AudioService.setMode(mode);
AudioSystem.setMode(mode);（native function)
android_media_AudioSystem.cpp==>android_media_AudioSystem_setMode()
AudioSystem.cpp==>setMode()
const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
binder = sm->getService(String16("media.audio_flinger"));
...
gAudioFlinger = interface_cast<IAudioFlinger>(binder);
...
return gAudioFlinger;

通过查找“media.audio_flinger”发现AudioFlinger.cpp==>instantiate()//Main_mediaserver.cpp中被实例化。
defaultServiceManager()->addService(String16("media.audio_flinger"), new AudioFlinger())
mAudioHardware = AudioHardwareInterface::create();
LOGV("Creating Vendor Specific AudioHardware");
hw = createAudioHardware();
return new AudioHardwareMarvell();
return af->setMode(mode);
AudioHardwareLittle.cpp==>setMode(mode)
doRouting();
enable_incall_headphone()//or others...
system("alsactl -f /etc/alsactl/asound.state_none restore");
system("alsactl -f /etc/alsactl/asound.state_headset_r_s restore");
6.2、来电播放振铃,挂断或接听停止振铃。
==>Phone.app
onCreate()
ringer = new Ringer(phone);
Vibrator mVibrator = new Vibrator();
mService = IHardwareService.Stub.asInterface(ServiceManager.getService("hardware"));
notifier = new CallNotifier(this, phone, ringer, mBtHandsfree);
mPhone.registerForIncomingRing(this, PHONE_INCOMING_RING, null);
mPhone.registerForPhoneStateChanged(this, PHONE_STATE_CHANGED, null);
mPhone.registerForDisconnect(this, PHONE_DISCONNECT, null);
...
case PHONE_INCOMING_RING:
mRinger.ring();
mHardwareService.setAttentionLight(true);
mVibratorThread.start();
while (mContinueVibrating) {
mVibrator.vibrate(VIBRATE_LENGTH);
SystemClock.sleep(VIBRATE_LENGTH + PAUSE_LENGTH);
}
...
makeLooper();
mRingHandler.sendEmptyMessage(PLAY_RING_ONCE);
...
case PLAY_RING_ONCE:
PhoneUtils.setAudioMode(mContext, AudioManager.MODE_RINGTONE);
r.play();
...
case PHONE_DISCONNECT:
case PHONE_STATE_CHANGED:
...
mRinger.stopRing();
Message msg = mRingHandler.obtainMessage(STOP_RING);
msg.obj = mRingtone;
mRingHandler.sendMessage(msg);
case STOP_RING:
r.stop();
getLooper().quit();
...
mVibrator.cancel();
第七部分：通话相关的notification服务
7、通话相关的notification服务。
7.1、NotificationMgr
==>PhoneApp.java
onCreate()
NotificationMgr.init(this)//NotificationMgr.java//此类主要负责电话通知的具体表现（通知和取消通知），未接图标、通话中、蓝牙激活中、保持中，静音、免提等。封装了简单的瞬间显示文本消息的功能。提供漫游数据连接禁止的通知封装和漫游数据连接允许时取消通知
sMe = new NotificationMgr(context);
mNotificationMgr = (NotificationManager
context.getSystemService(Context.NOTIFICATION_SERVICE);
mStatusBar = (StatusBarManager) context.getSystemService(Context.STATUS_BAR_SERVICE); //主要用于显示静音和speaker状态的图表（在状态条右边显示）
sMe.updateNotifications();//主要功能是：
1、查询是否有未读的未接听电话，并显示到状态栏图标，和通知列表
2、根据是否是电话状态，更新状态栏图表和通知列表（可能是激活，蓝牙，保持等）
7.2、CallNotifier
==>PhoneApp.java
onCreate()
notifier = new CallNotifier(this, phone, ringer, mBtHandsfree);//此类主要是监听通话相关的事件，然后进行例如来电播放铃声，震动。挂断、接听停止振铃等（调用Ringer类实现此功能)，根据不同的状态调用调用NotificationMgr进行具体的通知和取消通知。
第八部分： 通话相关的各种server
电话通信相关的服务：
(1)、从ServiceManager得到的：
a、wifiService
b、PhoneInterfaceManager
c、PhoneSubInfo
d、SimPhoneBookInterfaceManager
e、SimSmsInterfaceManager
f、TelephonyRegistry
g、NetStatService
h、ConnectivityService
(2)、从ApplicationContext得到的：
a、TelephonyManager