APN 建立PDP流程

GsmDataConnectiontracker.java中：
        private class ApnChangeObserver extends ContentObserver {
        public ApnChangeObserver () {
            super(mDataConnectionTracker);
        }

        @Override
        public void onChange(boolean selfChange) {
            sendMessage(obtainMessage(EVENT_APN_CHANGED));
        }
        }
handle处理：
    case EVENT_APN_CHANGED:
                onApnChanged();
                break;
调用方法：
         /**
         * Handles changes to the APN database.
         */
        private void onApnChanged() {
        boolean isConnected;

        isConnected = (state != State.IDLE && state != State.FAILED);

        if (hasFwkChangedPreferredApn) {
            hasFwkChangedPreferredApn = false;
            return;
        }
        // The "current" may no longer be valid.  MMS depends on this to send properly.
        mGsmPhone.updateCurrentCarrierInProvider();

        // TODO: It'd be nice to only do this if the changed entrie(s)
        // match the current operator.
        createAllApnList();
        if (state != State.DISCONNECTING) {
            cleanUpConnection(isConnected, Phone.REASON_APN_CHANGED);
            if (!isConnected) {
                // reset reconnect timer
                mRetryMgr.resetRetryCount();
                mReregisterOnReconnectFailure = false;
                trySetupData(Phone.REASON_APN_CHANGED);
            }
        }
        }

    private boolean setupData(String reason) {
        ApnSetting apn;
        GsmDataConnection pdp;

        apn = getNextApn();
        if (apn == null) return false;
        pdp = findFreePdp();
        if (pdp == null) {
            if (DBG) log("setupData: No free GsmDataConnection found!");
            return false;
        }
        mActiveApn = apn;
        mActivePdp = pdp;

        Message msg = obtainMessage();
        msg.what = EVENT_DATA_SETUP_COMPLETE;
        msg.obj = reason;
        pdp.connect(msg, apn);

        setState(State.INITING);
        phone.notifyDataConnection(reason);
        return true;
        }
DataConnection中：
        /**
         * Connect to the apn and return an AsyncResult in onCompletedMsg.
         * Used for cellular networks that use Acess Point Names (APN) such
         * as GSM networks.
         *
         * @param onCompletedMsg is sent with its msg.obj as an AsyncResult object.
         *        With AsyncResult.userObj set to the original msg.obj,
         *        AsyncResult.result = FailCause and AsyncResult.exception = Exception().
         * @param apn is the Acces Point Name to connect to
         */
        public void connect(Message onCompletedMsg, ApnSetting apn) {
        sendMessage(obtainMessage(EVENT_CONNECT, new ConnectionParams(apn, onCompletedMsg)));
        }
handle处理：
    case EVENT_CONNECT:
                    if (DBG) log("DcInactiveState msg.what=EVENT_CONNECT");
                    ConnectionParams cp = (ConnectionParams) msg.obj;
                    cp.tag = mTag;
                    onConnect(cp);
                    transitionTo(mActivatingState);
                    retVal = true;
                    break;

GsmDataConnection。java处理：
     protected
        void onConnect(ConnectionParams cp) {
        apn = cp.apn;

        if (DBG) log("Connecting to carrier: '" + apn.carrier
                + "' APN: '" + apn.apn
                + "' proxy: '" + apn.proxy + "' port: '" + apn.port);

        setHttpProxy (apn.proxy, apn.port);

        createTime = -1;
        lastFailTime = -1;
        lastFailCause = FailCause.NONE;

        // msg.obj will be returned in AsyncResult.userObj;
        Message msg = obtainMessage(EVENT_SETUP_DATA_CONNECTION_DONE, cp);
        msg.obj = cp;

        int authType = apn.authType;
        if (authType == -1) {
            authType = ((apn.user != null) && (apn.user.length() != 0)) ?
                    RILConstants.SETUP_DATA_AUTH_PAP_CHAP : RILConstants.SETUP_DATA_AUTH_NONE;
        }

        String protocol;
        if (Phone.REASON_IPV6_FALLBACK.equals(cp.onCompletedMsg.obj)) {
            // IPv6 fail, fallback to IPv4
            if (DBG) log("IPv6 fail, fallback to IPv4, set protocal to IP");
            protocol = "IP";
        } else if (phone.getServiceState().getRoaming()) {
            protocol = apn.roamingProtocol;
        } else {
            protocol = apn.protocol;
        }

        phone.mCM.setupDataCall(
                Integer.toString(RILConstants.SETUP_DATA_TECH_GSM),
                Integer.toString(RILConstants.DATA_PROFILE_DEFAULT),
                apn.apn, apn.user, apn.password, Integer.toString(authType),
                protocol, msg);
        }

Ril。java处理：
    public void
        setupDataCall(String radioTechnology, String profile, String apn,
            String user, String password, String authType, String protocol,
            Message result) {
        RILRequest rr
                = RILRequest.obtain(RIL_REQUEST_SETUP_DATA_CALL, result);

        rr.mp.writeInt(7);

        rr.mp.writeString(radioTechnology);
        rr.mp.writeString(profile);
        rr.mp.writeString(apn);
        rr.mp.writeString(user);
        rr.mp.writeString(password);
        rr.mp.writeString(authType);
        rr.mp.writeString(protocol);

        if (RILJ_LOGD) riljLog(rr.serialString() + "> "
                + requestToString(rr.mRequest) + " " + radioTechnology + " "
                + profile + " " + apn + " " + user + " "
                + password + " " + authType + " " + protocol);

        send(rr);
        }

DataConnection处理消息：
    case EVENT_SETUP_DATA_CONNECTION_DONE:
        724                     if (DBG) log("DcActivatingState msg.what=EVENT_SETUP_DATA_CONNECTION_DONE");
        725
        726                     ar = (AsyncResult) msg.obj;
        727                     cp = (ConnectionParams) ar.userObj;
        728
        729                     SetupResult result = onSetupConnectionCompleted(ar);
        730                     switch (result) {
        731                         case SUCCESS:
        732                             // All is well
        733                             mActiveState.setEnterNotificationParams(cp, FailCause.NONE);
        734                             transitionTo(mActiveState);
        735                             break;
        736                         case ERR_BadCommand:
        737                             // Vendor ril rejected the command and didn't connect.
        738                             // Transition to inactive but send notifications after
        739                             // we've entered the mInactive state.
        740                             mInactiveState.setEnterNotificationParams(cp, result.mFailCause);
        741                             transitionTo(mInactiveState);
        742                             break;
        743                         case ERR_BadDns:
        744                             // Connection succeeded but DNS info is bad so disconnect
        745                             EventLog.writeEvent(EventLogTags.PDP_BAD_DNS_ADDRESS, dnsServers[0]);
        746                             tearDownData(cp);
        747                             transitionTo(mDisconnectingBadDnsState);
        748                             break;
        749                         case ERR_Other:
        750                             // Request the failure cause and process in this state
        751                             phone.mCM.getLastDataCallFailCause(
        752                                     obtainMessage(EVENT_GET_LAST_FAIL_DONE, cp));
        753                             break;
        754                         case ERR_Stale:
        755                             // Request is stale, ignore.
        756                             break;
        757                         default:
        758                             throw new RuntimeException("Unkown SetupResult, should not happen");
        759                     }
        760                     retVal = true;
        761                     break;

DcActiveState extends HierarchicalState的方法：

        @Override public void enter() {
            /**
             * Now that we've transitioned to Active state we
             * can send notifications. Previously we sent the
             * notifications in the processMessage handler but
             * that caused a race condition because the synchronous
             * call to isActive.
             */
            if ((mConnectionParams != null) && (mFailCause != null)) {
                log("DcActiveState: enter notifyConnectCompleted");
                notifyConnectCompleted(mConnectionParams, mFailCause);
            }
        }
GsmDataConnectiontracker.java:
    protected void onDataSetupComplete(AsyncResult ar) {
        String reason = null;
        if (ar.userObj instanceof String) {
            reason = (String) ar.userObj;
        }

        if (ar.exception == null) {
            // everything is setup
            if (isApnTypeActive(Phone.APN_TYPE_DEFAULT)) {
                SystemProperties.set("gsm.defaultpdpcontext.active", "true");
                        if (canSetPreferApn && preferredApn == null) {
                            Log.d(LOG_TAG, "PREFERRED APN is null");
                            preferredApn = mActiveApn;
                            setPreferredApn(preferredApn.id);
                        }
            } else {
                SystemProperties.set("gsm.defaultpdpcontext.active", "false");
            }
            notifyDefaultData(reason);

            // TODO: For simultaneous PDP support, we need to build another
            // trigger another TRY_SETUP_DATA for the next APN type.  (Note
            // that the existing connection may service that type, in which
            // case we should try the next type, etc.
        } else {
            GsmDataConnection.FailCause cause;
            cause = (GsmDataConnection.FailCause) (ar.result);
            if(DBG) log("PDP setup failed " + cause);
                    // Log this failure to the Event Logs.
            if (cause.isEventLoggable()) {
                GsmCellLocation loc = ((GsmCellLocation)phone.getCellLocation());
                EventLog.writeEvent(EventLogTags.PDP_SETUP_FAIL,
                        cause.ordinal(), loc != null ? loc.getCid() : -1,
                        TelephonyManager.getDefault().getNetworkType());
            }

            // set the first default apn to preferred apn.
            Boolean enableDefaultPreferredApn = CustomizedValues.getBoolean(
                    DEFAULT_PREFERRED_APN_PROPERTY, false);
            if (enableDefaultPreferredApn && isApnTypeActive(Phone.APN_TYPE_DEFAULT)) {
                if (canSetPreferApn && preferredApn == null && mActiveApn != null) {
                    if(DBG) log("set first preferred APN is null");
                    preferredApn = mActiveApn;
                    setPreferredApn(preferredApn.id);
                }
            }

            if (!waitingApns.isEmpty()) {
                // Count permanent failures and remove the APN we just tried
                if (cause.isPermanentFail()
                        && !(cause.isIpv6FallBackCause() && mActiveApn != null
                                && APN_PROTOCOL_IPV6.equals(mActiveApn.protocol))) {
                    waitingApnsPermanentFailureCountDown--;
                }
                waitingApns.remove(0);
            }
            else {
                if (DBG) log("onDataSetupComplete: waitingApns cleared from outside!");
                // Consider this a error case, reset the Countdown
                waitingApnsPermanentFailureCountDown = 0;
            }
            if (DBG) log(String.format("onDataSetupComplete: waitingApns.size=%d" +
                            " waitingApnsPermanenatFailureCountDown=%d",
                            waitingApns.size(), waitingApnsPermanentFailureCountDown));

            // See if there are more APN's to try
            if (waitingApns.isEmpty()) {
                if (waitingApnsPermanentFailureCountDown == 0) {
                    if (DBG) log("onDataSetupComplete: Permanent failures stop retrying");
                    notifyNoData(cause);
                    phone.notifyDataConnection(Phone.REASON_APN_FAILED);
                } else {
                    if (DBG) log("onDataSetupComplete: Not all permanent failures, retry");
                    startDelayedRetry(cause, reason);
                }
            } else {
                if (DBG) log("onDataSetupComplete: Try next APN");
                setState(State.SCANNING);
                // Wait a bit before trying the next APN, so that
                // we're not tying up the RIL command channel
                sendMessageDelayed(obtainMessage(EVENT_TRY_SETUP_DATA, reason), APN_DELAY_MILLIS);
            }
        }
        }