Android 5.1 open data flow 数据开启流程

首先我们来看看下面的关系图：

底层Settings.apk

在Settings -> Data Usage Summary中的某个SIM tab下开启数据开关

android/packages/apps/Settings/src/com/android/settings/DataUsageSummary.java

setMobileDataEnabled(true);

private View.OnClickListener mDataEnabledListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mBinding) return;

            final boolean dataEnabled = !mDataEnabled.isChecked();
            final String currentTab = mCurrentTab;
            if (TAB_MOBILE.equals(currentTab) || currentTab.startsWith(TAB_SIM)) {
                if (dataEnabled) {
                    setMobileDataEnabled(true);
                    if (mPolicyEditor.getPolicyWarningBytes(mTemplate) == WARNING_DISABLED) {
                        mPolicyEditor.setPolicyWarningBytes(mTemplate, 2 * GB_IN_BYTES);
                    }
                } else {
                    // disabling data; show confirmation dialog which eventually
                    // calls setMobileDataEnabled() once user confirms.
                    ConfirmDataDisableFragment.show(DataUsageSummary.this);
                }
            }

            updatePolicy(false);
        }
    };

下面这部根据phoneId获得了当前获得了SubId

mTelephonyManager.setDataEnabled(subId[0],
enabled);

   private void setMobileDataEnabled(boolean enabled) {
        if (LOGD) Log.d(TAG, "setMobileDataEnabled()");
        // How about exposing sub based API like TelephonyManager.setDataEnabled(int subId);
        if (mCurrentTab.startsWith(TAB_SIM)) {
            int phoneId = multiSimGetCurrentSub();

            // as per phone, set the individual flag
            android.provider.Settings.Global.putInt(getActivity().getContentResolver(),
                    android.provider.Settings.Global.MOBILE_DATA + phoneId, enabled ? 1 : 0);

            int[] subId = SubscriptionManager.getSubId(phoneId);
            mTelephonyManager.setDataEnabled(subId[0], enabled);
        } else {
            mTelephonyManager.setDataEnabled(enabled);
            mMobileDataEnabled = enabled;
        }
        updatePolicy(false);
    }

frameworks/base

数据开关都会调用到TelephonyManager.setDataEnabled()，不管是从流量使用情况还是从下拉的“快速设置”（Quick Setting）里打开（这里会在后面补充说明）

android/frameworks/base/telephony/java/android/telephony/TelephonyManager.java

getITelephony().setDataEnabled(subId,
enable);

 /** @hide */
    @SystemApi
    public void setDataEnabled(int subId, boolean enable) {
        try {
            AppOpsManager appOps = (AppOpsManager)mContext.getSystemService(Context.APP_OPS_SERVICE);
            if (enable) {
                if (appOps.noteOp(AppOpsManager.OP_DATA_CONNECT_CHANGE) != AppOpsManager.MODE_ALLOWED) {
                    Log.w(TAG, "Permission denied by user.");
                    return;
                }
            }
            Log.d(TAG, "setDataEnabled: enabled=" + enable);
            getITelephony().setDataEnabled(subId, enable);
        } catch (RemoteException e) {
            Log.e(TAG, "Error calling setDataEnabled", e);
        }
    }

android/packages/services/Telephony/src/com/android/phone/PhoneInterfaceManager.java

到这里才是设置phone的数据开启

phone.setDataEnabled(enable);

    /**
     * Set mobile data enabled
     * Used by the user through settings etc to turn on/off mobile data
     *
     * @param enable {@code true} turn turn data on, else {@code false}
     */
    @Override
    public void setDataEnabled(int subId, boolean enable) {
        enforceModifyPermission();
        int phoneId = mSubscriptionController.getPhoneId(subId);
        log("getDataEnabled: subId=" + subId + " phoneId=" + phoneId);
        Phone phone = PhoneFactory.getPhone(phoneId);
        if (phone != null) {
            log("setDataEnabled: subId=" + subId + " enable=" + enable);
            phone.setDataEnabled(enable);
        } else {
            loge("setDataEnabled: no phone for subId=" + subId);
        }
    }

android/frameworks/opt/telephony/src/java/com/android/internal/telephony/gsm/GSMPhone.java

mDcTracker.setDataEnabled(enable);

 @Override
    public void setDataEnabled(boolean enable) {
        mDcTracker.setDataEnabled(enable);
    }

 android/rameworks/opt/telephony/src/java/com/android/internal/telephony/dataconnection/DcTrackerBase.java   

发送打开数据开关的消息CMD_SET_USER_DATA_ENABLE

Message
msg =
obtainMessage(DctConstants.CMD_SET_USER_DATA_ENABLE);

 /**
     * Modify {@link android.provider.Settings.Global#MOBILE_DATA} value.
     */
    public void setDataEnabled(boolean enable) {
        Message msg = obtainMessage(DctConstants.CMD_SET_USER_DATA_ENABLE);
        msg.arg1 = enable ? 1 : 0;
        sendMessage(msg);
    }

处理消息

onSetUserDataEnabled(enabled);

 @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
            case AsyncChannel.CMD_CHANNEL_DISCONNECTED: {
                log("DISCONNECTED_CONNECTED: msg=" + msg);
                DcAsyncChannel dcac = (DcAsyncChannel) msg.obj;
                mDataConnectionAcHashMap.remove(dcac.getDataConnectionIdSync());
                dcac.disconnected();
                break;
            }
            ...
            case DctConstants.CMD_SET_USER_DATA_ENABLE: {
                final boolean enabled = (msg.arg1 == DctConstants.ENABLED) ? true : false;
                if (DBG) log("CMD_SET_USER_DATA_ENABLE enabled=" + enabled);
                onSetUserDataEnabled(enabled);
                break;
            }
...

onTrySetupData(Phone.REASON_DATA_ENABLED);

 protected void onSetUserDataEnabled(boolean enabled) {
        synchronized (mDataEnabledLock) {
            if (mUserDataEnabled != enabled) {
                mUserDataEnabled = enabled;
                Settings.Global.putInt(mPhone.getContext().getContentResolver(),
                        Settings.Global.MOBILE_DATA + mPhone.getPhoneId(), enabled ? 1 : 0);
                if (getDataOnRoamingEnabled() == false &&
                        mPhone.getServiceState().getRoaming() == true) {
                    if (enabled) {
                        notifyOffApnsOfAvailability(Phone.REASON_ROAMING_ON);
                    } else {
                        notifyOffApnsOfAvailability(Phone.REASON_DATA_DISABLED);
                    }
                }

                if (enabled) {
                    onTrySetupData(Phone.REASON_DATA_ENABLED);
                } else {
                    onCleanUpAllConnections(Phone.REASON_DATA_SPECIFIC_DISABLED);
                }
            }
        }
    }

android/frameworks/opt/telephony/src/java/com/android/internal/telephony/dataconnection/DcTracker.java

setupDataOnConnectableApns(reason);

 @Override
    // TODO: We shouldnt need this.
    protected boolean onTrySetupData(String reason) {
        if (DBG) log("onTrySetupData: reason=" + reason);
        setupDataOnConnectableApns(reason);
        return true;
    }

trySetupData(apnContext);

<span style="background-color: rgb(255, 255, 255);"> private void setupDataOnConnectableApns(String reason) {
        if (DBG) log("setupDataOnConnectableApns: " + reason);

        for (ApnContext apnContext : mPrioritySortedApnContexts) {
            if (DBG) log("setupDataOnConnectableApns: apnContext " + apnContext);
            if (apnContext.getState() == DctConstants.State.FAILED) {
                apnContext.setState(DctConstants.State.IDLE);
            }
            if (apnContext.isConnectable()) {
                log("setupDataOnConnectableApns: isConnectable() call trySetupData");
                apnContext.setReason(reason);
                trySetupData(apnContext);
            }
        }
    }</span>

下面这个方法比较长，有很多条件的检查

boolean
retValue =setupData(apnContext,
radioTech);

  private boolean trySetupData(ApnContext apnContext) {
        ...
        if (apnContext.isConnectable() && (isEmergencyApn ||

                (isDataAllowed(apnContext) &&
                getAnyDataEnabled(checkUserDataEnabled) && !isEmergency()))) {
            if (apnContext.getState() == DctConstants.State.FAILED) {
                if (DBG) log("trySetupData: make a FAILED ApnContext IDLE so its reusable");
                apnContext.setState(DctConstants.State.IDLE);
            }
            int radioTech = mPhone.getServiceState().getRilDataRadioTechnology();
            if (apnContext.getState() == DctConstants.State.IDLE) {

                ArrayList<ApnSetting> waitingApns = buildWaitingApns(apnContext.getApnType(),
                        radioTech);
                if (waitingApns.isEmpty()) {
                    notifyNoData(DcFailCause.MISSING_UNKNOWN_APN, apnContext);
                    notifyOffApnsOfAvailability(apnContext.getReason());
                    if (DBG) log("trySetupData: X No APN found retValue=false");
                    return false;
                } else {
                    apnContext.setWaitingApns(waitingApns);
                    if (DBG) {
                        log ("trySetupData: Create from mAllApnSettings : "
                                    + apnListToString(mAllApnSettings));
                    }
                }
            }

            if (DBG) {
                log("trySetupData: call setupData, waitingApns : "
                        + apnListToString(apnContext.getWaitingApns()));
            }
            boolean retValue = setupData(apnContext, radioTech);//7
            notifyOffApnsOfAvailability(apnContext.getReason());

            if (DBG) log("trySetupData: X retValue=" + retValue);
            return retValue;
        } else {
            if (!apnContext.getApnType().equals(PhoneConstants.APN_TYPE_DEFAULT)
                    && apnContext.isConnectable()) {
                mPhone.notifyDataConnectionFailed(apnContext.getReason(), apnContext.getApnType());
            }
            notifyOffApnsOfAvailability(apnContext.getReason());
            if (DBG) log ("trySetupData: X apnContext not 'ready' retValue=false");
            return false;
        }
    }

dcac.bringUp(apnContext,
getInitialMaxRetry(), profileId, radioTech, mAutoAttachOnCreation,msg);

 private boolean setupData(ApnContext apnContext, int radioTech) {
        if (DBG) log("setupData: apnContext=" + apnContext);
        ApnSetting apnSetting;
        DcAsyncChannel dcac = null;

        apnSetting = apnContext.getNextWaitingApn();
        if (apnSetting == null) {
            if (DBG) log("setupData: return for no apn found!");
            return false;
        }

        int profileId = apnSetting.profileId;
        if (profileId == 0) {
            profileId = getApnProfileID(apnContext.getApnType());
        }

        // On CDMA, if we're explicitly asking for DUN, we need have
        // a dun-profiled connection so we can't share an existing one
        // On GSM/LTE we can share existing apn connections provided they support
        // this type.
        if (apnContext.getApnType() != PhoneConstants.APN_TYPE_DUN ||
                teardownForDun() == false) {
            dcac = checkForCompatibleConnectedApnContext(apnContext);
            if (dcac != null) {
                // Get the dcacApnSetting for the connection we want to share.
                ApnSetting dcacApnSetting = dcac.getApnSettingSync();
                if (dcacApnSetting != null) {
                    // Setting is good, so use it.
                    apnSetting = dcacApnSetting;
                }
            }
        }
        if (dcac == null) {
            if (isOnlySingleDcAllowed(radioTech)) {
                if (isHigherPriorityApnContextActive(apnContext)) {
                    if (DBG) {
                        log("setupData: Higher priority ApnContext active.  Ignoring call");
                    }
                    return false;
                }

                // Only lower priority calls left.  Disconnect them all in this single PDP case
                // so that we can bring up the requested higher priority call (once we receive
                // repsonse for deactivate request for the calls we are about to disconnect
                if (cleanUpAllConnections(true, Phone.REASON_SINGLE_PDN_ARBITRATION)) {
                    // If any call actually requested to be disconnected, means we can't
                    // bring up this connection yet as we need to wait for those data calls
                    // to be disconnected.
                    if (DBG) log("setupData: Some calls are disconnecting first.  Wait and retry");
                    return false;
                }

                // No other calls are active, so proceed
                if (DBG) log("setupData: Single pdp. Continue setting up data call.");
            }

            dcac = findFreeDataConnection();

            if (dcac == null) {
                dcac = createDataConnection();
            }

            if (dcac == null) {
                if (DBG) log("setupData: No free DataConnection and couldn't create one, WEIRD");
                return false;
            }
        }
        if (DBG) log("setupData: dcac=" + dcac + " apnSetting=" + apnSetting);

        apnContext.setDataConnectionAc(dcac);
        apnContext.setApnSetting(apnSetting);
        apnContext.setState(DctConstants.State.CONNECTING);
        mPhone.notifyDataConnection(apnContext.getReason(), apnContext.getApnType());

        Message msg = obtainMessage();
        msg.what = DctConstants.EVENT_DATA_SETUP_COMPLETE;
        msg.obj = apnContext;
        dcac.bringUp(apnContext, getInitialMaxRetry(), profileId, radioTech, mAutoAttachOnCreation,
                msg);//8

        if (DBG) log("setupData: initing!");
        return true;
    }

android/frameworks/opt/telephony/src/java/com/android/internal/telephony/dataconnection/DcAsyncChannel.java

sendMessage

 /**
     * Bring up a connection to the apn and return an AsyncResult in onCompletedMsg.
     * Used for cellular networks that use Acesss Point Names (APN) such
     * as GSM networks.
     *
     * @param apnContext is the Access Point Name to bring up a connection to
     * @param initialMaxRetry the number of retires for initial bringup.
     * @param profileId for the conneciton
     * @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().
     */
    public void bringUp(ApnContext apnContext, int initialMaxRetry, int profileId,
            int rilRadioTechnology, boolean retryWhenSSChange, Message onCompletedMsg) {
        if (DBG) {
            log("bringUp: apnContext=" + apnContext + " initialMaxRetry=" + initialMaxRetry
                + " onCompletedMsg=" + onCompletedMsg);
        }
        sendMessage(DataConnection.EVENT_CONNECT,//9
                    new ConnectionParams(apnContext, initialMaxRetry, profileId,
                            rilRadioTechnology, retryWhenSSChange, onCompletedMsg));
    }

android/frameworks/opt/telephony/src/java/com/android/internal/telephony/dataconnection/DataConnection.java

这其实是个状态即机 StateMachine，这个类或者或机制，本身也比较复杂，以后看明白了以后会单独在写一篇文章

现在是进入其中一个状态DcInactiveState。

DcInactiveState processmesssage

onConnect(mConnectionParams);

   /**
     * The state machine is inactive and expects a EVENT_CONNECT.
     */
    private class DcInactiveState extends State {
       ...

        @Override
        public boolean processMessage(Message msg) {
       ...                            

            case EVENT_CONNECT:
                    if (DBG) log("DcInactiveState: mag.what=EVENT_CONNECT");
                    ConnectionParams cp = (ConnectionParams) msg.obj;
                    if (initConnection(cp)) {
                        onConnect(mConnectionParams);//10
                        transitionTo(mActivatingState);
                    } else {
                        if (DBG) {
                            log("DcInactiveState: msg.what=EVENT_CONNECT initConnection failed");
                        }
                        notifyConnectCompleted(cp, DcFailCause.UNACCEPTABLE_NETWORK_PARAMETER,
                                false);
                    }
                    retVal = HANDLED;
                    break;

mPhone.mCi.setupDataCall

    /**
     * Begin setting up a data connection, calls setupDataCall
     * and the ConnectionParams will be returned with the
     * EVENT_SETUP_DATA_CONNECTION_DONE AsyncResul.userObj.
     *
     * @param cp is the connection parameters
     */
    private void onConnect(ConnectionParams cp) {
        if (DBG) log("onConnect: carrier='" + mApnSetting.carrier
                + "' APN='" + mApnSetting.apn
                + "' proxy='" + mApnSetting.proxy + "' port='" + mApnSetting.port + "'");

        // Check if we should fake an error.
        if (mDcTesterFailBringUpAll.getDcFailBringUp().mCounter  > 0) {
           ...
        }

        mCreateTime = -1;
        mLastFailTime = -1;
        mLastFailCause = DcFailCause.NONE;

        // The data profile's profile ID must be set when it is created.
        int dataProfileId;
        if (mApnSetting.getApnProfileType() == ApnProfileType.PROFILE_TYPE_OMH) {
            dataProfileId = mApnSetting.getProfileId() + RILConstants.DATA_PROFILE_OEM_BASE;
            log("OMH profile, dataProfile id = " + dataProfileId);
        } else {
            dataProfileId = cp.mProfileId;
        }

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

        int authType = mApnSetting.authType;
        if (authType == -1) {
            authType = TextUtils.isEmpty(mApnSetting.user) ? RILConstants.SETUP_DATA_AUTH_NONE
                    : RILConstants.SETUP_DATA_AUTH_PAP_CHAP;
        }

        String protocol;
        if (mPhone.getServiceState().getRoaming()) {
            protocol = mApnSetting.roamingProtocol;
        } else {
            protocol = mApnSetting.protocol;
        }

        mPhone.mCi.setupDataCall(//11
                Integer.toString(cp.mRilRat + 2),
                Integer.toString(dataProfileId),
                mApnSetting.apn, mApnSetting.user, mApnSetting.password,
                Integer.toString(authType),
                protocol, msg);
    }

android/frameworks/opt/telephony/src/java/com/android/internal/telephony/RIL.java
这个类是通讯中的使用类。