embedded software lab. @ skku 51 1 tizen v2.3 system & app framework

Embedded Software Lab. @ SKKU

51

1

Tizen v2.3 System & App Framework


51

2

• Overview– System & App FW– What is Ecore?

• System Framework– Overview– Deviced– Inter-process Communication– Sensor Framework

• App Framework– Overview– Appcore– AUL– App Service– Package Manager, AIL, RUA

Contents


51

3

• System Framework– System managements and Device Abstractions

• System condition management Low memory, Low battery, process, CPU frequency handling

• Device abstraction and control display, mmc, earjack, GPS, haptic, etc.

– System logging dlog– Sensor management sensor server and client library

• App Framework– Application main loop– Inter-app communication and launching– Application Install & Uninstall– System event callback

Overview


51

4

System Framework


51

5System FW Overview


51

6Deviced Architecture


51

7

• System monitoring, managing, notifying– Battery, display, vibrator, led, mmc, power, USB, storage, extcon

devices

• Use Ecore main_loop for event handling– main() (main.c)• ecore_init(): initializing Ecore• deviced_main()

– edbus_init: initializing Ecore dbus –deviced_init(): initializing deviced components»Display, storage, USB, lowbat … etc.

–notification to systemd– ecore_main_loop_begin(): start main loop of ecore

Deviced (framework/system/deviced/core)


51

8Deviced (framework/system/deviced/core)

DD_LIST_APPEND(device_ops, List)


51

9

• Ecore: EFL core library for application– “Operating system abstraction and integration”,

http://enlightenment.org – Event-driven main loop Because GUI application is

event-driven. • Many GUI Toolkit use event-driven main loop, ex) Glib

– Frequently switch between IDLE / Event handling• save core resource

– Can handle file descriptor and signal event• socket, pipe, vconf, IPC, etc.• Also able to use in non-GUI event driven program

What is Ecore? (Event main loop)


51

10

• Double linked list to handle device operation– “eina_list_*” functions are provided by enlightenment– eina_list_append(Eina_List *list, const void *data)

• Append the given data to the given linked list.

– eina_list_nth(const Eina_List * list, unsigned int n)• Get the n`th member's data pointer in a list.

list.h

Display•EINA_LIST_APPEND(lcdon_ops, ops);Gpio•DD_LIST_APPEND(gpio_head, (void*)gpio);USB•DD_LIST_APPEND(storage_job, job);MMC•DD_LIST_APPEND(fs_head, (void*)fs);

Various list types


51

11

• Perform device registration and management– add_device() / remove_device() / find_device()

• Use “eina_list_*” functions

– devices_init() / device_exit() / device_start() / device_stop() / device_execute()• Execute each function of device_ops

devices.c

Start/Stop flags


51

12

• ./touch/touchscreen.c– Enable / Disable touchscreen on specific status

Device Registration Example

Each device is registered automatically in module initializing process

Check flag

sys_get_int(path,value) •provides access to kernel device driver node parameters


51

13

• register_notifier()– Register Notification (Function) for specific status

• device_notify()– Execute registered function

device-notifier.c


51

14

• Provide information and callback function for device status change – Use udev

• basic way to get a event from kernel in deviced

– Support below devices• Input / extcon / power_supply / USB / block device

• Register_uevent_control(“Subsystem & Handler”)• Unregister_uevent_control(“Subsystem &

Handler”)– Event control management

udev.h / device-change-handler.c

Subsystem / Path Handler


51

15Deviced Schema


51

16

• Other system events (battery, USB connection, Device change, MMC device) are also similar as touchscreen– Module structure– Register device operation functions

• Init / Exit / Start / Stop / Status / Execute

– Use device flags

• Handle only the system-level events for devices

• Storage I/O will not be handled from deviced

Others


51

17

• Various Inter-process communication– heynoti– ss_sysnoti– socket– pipe– vconf– dbus

Inter-process communication


51

18

• ligHt, Easy, speedY• light-weight notification library– using inotify mechanism• alert filesystem event

– doesn't support data delivery, just send event notification.

– To send event with data like integer, string, use DBus for IPC.

– simple mechanism• make inotify fd for specific name• subscribe for specific name• sender publishes notification• App notifies and handles notification

heynoti (framework/appfw/heynoti)


51

19

• Send event into system-server– Enable run_queue (in system-server) to handle the event from

proper handler– Using socket communication

• /libslp-sysman– Helper library to notify the message to system-server– sysnoti.c

• sysnoti_send(msg): send socket msg into /tmp/sn• sysman_call_predef_action(): request into system-server to run predefined

function for the event

ss_sysnoti


51

20

• Key-value fair + inotify– Various functionality than heynoti

• Store system configuration using SQLite (libsqlfs)• Able to communicate between inter-process using inotify

vconf (framework/appfw/vconf)


51

21

• Inter-process communication mechanism using socket– Using Dbus daemon, App (or process) can send message into

other App (or process)– Access control using SMACK

dbus


51

22

• Library that manages device node for each device in system– Not only real device, sysfs node also can be managed.– Add device node into device list, and register the callback function for

get and set request OAL Interface Function

• device_get_property– Get device information (through corresponding OAL interface function)

• device_set_property– Set device status (or command)

(with OAL interface function)

• OAL Interface– libslp_devman_plugin.so– System developer should make OAL

Interface library for each system devices

libdevice-node


51

23

• Types of Sensors – Sensor plugins retrieve data from sensor hardware and enable the client

applications to use the data – Tizen supports individual plugin frameworks for these sensors:

• Accelerometer sensor • Gyroscope sensor • Proximity sensor • Motion sensor • Geomagnetic sensor • Light sensor • Gravity sensor• Orientation sensor• Pressure sensor• Etc

Sensor Framework


51

24

• Accelerometer sensor – The accelerometer sensor is used to measure the acceleration of the device.

The three dimensional coordinate system is used to illustrate the direction of the acceleration. When a phone is moving along an axis, the acceleration is positive if it moves in a positive direction.

• Gyroscope sensor – A gyroscope is a device used primarily for navigation and measurement of

angular velocity. Gyroscopes measure how quickly an object rotates. This rate of rotation can be measured along any of the three axes X, Y, and Z.

• Proximity sensor – A proximity sensor can detect the presence of nearby objects without any

physical contact. That is, it indicates if the device is close or not close to the user.

• Motion sensor – A motion sensor is a virtual sensor that uses the accelerometer and

gyroscope sensors. Motion sensor detects snap, panning, tilt, shake, overturn, and double tap event.

• Geomagnetic sensor – A geomagnetic sensor indicates the strength of the geomagnetic flux density

in the X, Y, and Z axes. This sensor is used to find the orientation of a body, which is a description of how it is aligned to the space it is in.

Sensor details


51

25

• Light sensor – A light sensor measures the amount of light that it receives or the

surrounding light conditions. The ambient light state is measured as a step value, where 0 is very dark and 10 is bright sunlight.

• Gravity sensor– The gravity sensor is originated from the 3-axis acceleration sensor. It

calculate gravity vector based on measured data of 3-axis acceleration sensor. The gravity sensor outputs 4 values: 3 Cartesian axis values and a timestamp.

• Orientation sensor – The Orientation sensor can determine three angular positions (Azimuth / Pitch

/ Roll). It is consist of the 3-axis accelerometer sensor and 3-axis magnetic sensor

• Pressure sensor – The pressure sensor measures pressure, typically the pressure of gases or

liquids. The measurement unit is hPa. The min value is 260 hPa and the max value is 1260 hPa.

Sensor details


51

26

• Components of Sensor Framework – Sensor Server

• A daemon which communicates uniquely to sensor drivers in the system and dispatches sensor data to the application.

• Takes care of interacting with the sensor driver in hardware initialization, driver configuration, and data fetching, to manage all sensors on the platform.

– Sensor Client Library• The application that wants to access the sensor service should

communicate with the server through the sensor API library. • Allows the application to access the sensor service.

– Sensor Plugins• Retrieve data from sensor hardware and enable the client applications to

use the data for specific requirements. • Take care of interacting with the sensor driver. • Process data from sensor drivers and communicate it to the sensor server.

Sensor Framework details


51

27

• Interfaces of sensor plugins in sensor framework – Sensor_base

• Connect the sensor plugin to the sensor server

– Physical_sensor • Pushes sensor event from the plugin to the server event queue.

– Sensor_hal• Configure sensor driver and read raw sensor data from the sensor driver.

• Type of sensor plugins– Hardware sensor

• Sensor_base + physical_sensor + sensor_hal

– Virtual sensor• Sensor_base + virtual_sensor

Sensor Framework details


51

28

• Sensor Data Acquisition– How to acquire sensor data from device and notify sensor event

of application

• Sensor Data Acquisition Policies– Polling: ~Tizen 2.2– Event-driven: Tizen 2.3

Sensor Data Acquisition


51

29

• Application requires sensor data of server periodically.

Sensor Data Acquisition: Polling

• Used up to Tizen 2.2• Problem

– Sensor data requests for each application→ Too many kernel-device interactions→ Sensor event drop occur


51

30

• Application only register sensor event handler on server

Sensor Data Acquisition: Event-driven

• Used from Tizen 2.3• Sensor event drop problem resolved

– Kernel-device interaction is decreased

• Problem– Every registered sensor event handlers are called→ Increased IPC, Decreased CPU idle time

• cf. • Batching in Android 4.4~, • Model-driven in BraceForce


51

31

App Framework


51

32App Framework Overview


51

33Tizen Core Application Types

• UI Application– Application with UI (GUI)– Developed using EFL + Core APIs

• Service Application– Applications without UI

– Developed using Ecore (+α) + Core APIs


51

34

• Appcore is the application core handling various important events each of which application should be ware of.

• Using appcore, developers can– Manage application life-cycle

• Create, Reset, Pause, Resume, Terminate

– Handle System Events• Low Memory• Low Battery• Screen orientation Change• Language & Region Change

Appcore


51

35Appcore Internal callback


51

36

• Appcore registers default internal AUL handler in initialization

Appcore AUL Handler

appcore/appcore.c


51

37

• Include appcore-common.h or appcore-efl.h• fill appcore_ops for proper function pointers• call appcore_efl_main when using EFL

Using appcore

appcore/appcore-efl.cappcore/appcore-common.h


51

38Application Life Cycle: State and Transitions


51

39Tizen GUI App Structure


51

40

• Application Utility Library (AUL) provides the following features– Launching/terminating applications– Providing running application

information

• AUL consists of the following sub-components:– AUL library: Sending/receiving

requests for launching and terminating

– AUL daemon (a.k.a. launch pad): Handling the requests• Open socket file• wait for recv() at

__launchpad_main_loop

Application Utility Library: AUL

aul/launchpad.c


51

41

• In case of single-instance application– If app is not running, launch application – If app is already running, send reset event to the running

application

• In case of multi-instance application– launch an app

• _launchpad_main_loop()handles launch event

AUL: Launch

aul/launchpad.c


51

42App to Launchpad

aul/launch.caul/launch_app.c


51

43

• Application provides APN(application package name) to launch.• Unix Domain Socket is used to send events between launchpad

and applications.• Launchpad daemon is responsible for setup default configuration

of application.• DB is used to store / retain default configuration of application.

AUL Overall Architecture


51

44

• App service exposes general service terms, such as view, create, call, and so forth, to developers in case of launching an application with a specific feature– More desirable asking image view service without knowing what image

viewer apps are available.• Each service can be determined by given operation, URI and

MIME type.– Operation: expected action for the request (e.g., view, edit, call, send..)– URI: URI information for requested operation (e.g., http://... file://...)– MIME type: MIME type information for requested operation (e.g.,

image/jpeg)– Data: Extra data to launched service application(contained in a bundle

packet)

App Service (high-level App Launcher)


51

45App Service Overall Flow


51

46App Service Request


51

47

• The actual Application Data Exchange (ADE) occurs as an argument between the caller and callee, using a bundle.

• Bundle is a type of dictionary abstract data, in which information is stored as key-value pairs.

• Bundle contains information regarding the state the app should prepare.

Application Data Exchange


51

48

• Package manager is responsible for installing, upgrading and uninstalling of applications and storing their information.

• Expandable structure to support various types of applications– Designated installation modules can be added to the manager

• Web app, native app, java app, and so forth

Package Manager


51

49

• AIL is the library providing functionalities to execute application information-related tasks.

• AIL provides the following features– Adding, updating and removing application information.– Managing application's information –application name, type, icon path, exec

path, etc.– Retrieving an application list which meets a given filter.

Application Information Library: AIL


51

50

• Recently Used Application (RUA) logs application use history.– When an application is launched, launch pad updates the history

and task manager can either get or clear the history.

• RUA also provides below information regarding launching:– package name– launch time– application path– application launch argument

App Use History: RUA


51

51

• “An Overview of Tizen Application Core Framework”, TDC 2012

• “Tizen Core APIs: A Core Framework Layer to Build In-House Applications”, TDC 2014

• Tizen wiki, https://wiki.tizen.org • Tizen developer guide,

https://developer.tizen.org/dev-guide/2.3.0/• http://seoz.egloos.com

References

embedded software lab. @ skku 51 1 tizen v2.3 system & app framework

Documents