Embedded Software Lab. @ SKKU 43 1 Tizen System / App Framework.

Embedded Software Lab. @ SKKU

43

1

Tizen System / App Framework


43

2

• Overview (System & App FW)• What is Ecore?• System Framework• Application Framework

Contents


43

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


43

4

• 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)


43

5

System Framework


43

6

• https://wiki.tizen.org/wiki/Porting_Guide#System_Framework

System FW Overview


43

7

• System monitoring, managing, notifying– Low memory, low battery, USB connection, CPU frequency,

Process, etc.

• Use Ecore main_loop for event handling– main() (ss_main.c)

• ecore_init(): initializing Ecore• system_main()

– heynoti_init: initializing heynoti (notification library)– system_server_init(): initializing system server

» sysnoti, queue, core, predefine_internal» lowmem» lowbat … etc.

– notification to systemd

• ecore_main_loop_begin(): start main loop of ecore

System-server (framework/system/system-server)


43

8

• ss_sysnoti_init()– ss_sysnoti_server_init(): open socket server for inter-process

communication, and return file descriptor– register callback for the fd (/tmp/sn)

• synoti_cb()– call ss_action_entry_call() to create event ss_queue.c

ss_synoti.c


43

9

• Task runqueue for system-server– Handle action from internal or pipe handler

• ss_action_entry_add() / ss_action_entry_add_internal()– Specify action task and register to Eina list

• ss_action_entry_call() / ss_action_entry_call_internal()– Insert action into run_queue (based on the msg of action_entry)– ss_core_action_run() ss_core.c

• ss_run_queue_run()– run the ‘run_function’ for each action_entry

• Difference between internal or not– Internal: for internal source that will execute action.– non-internal: .so library will execute action using this ss_queue

interface new additional event can be served from system-server

ss_queue.c


43

10

• Execute run queue event from pipe

• ss_core_init()– Create unnamed pipe, and register call

backfunction for the pipe as core_pipe_cb

• core_pipe_cb()– Register _ss_core_action_run

as ‘run_function’ for run_queue

• ss_core_action_run– send msg (action run) into pipe

• _ss_core_action_run– Call predefine_action of run_queue_entry

ss_core.c


43

11

• Register predefine function for specific status– ss_action_entry_add_internal

• Example: lowmem

ss_predefine.c


43

12

• Low memory handler– Check memory status from sysfs in kernel (ecore)– Alert low memory situation into appcore (vconf)– Perform proper event according to memory status– Normal

• Only change vconf information

– Low• Remove all of shared memory with

zero reference count• Alert lowmem information using heynoti• Change vconf information

– Critical (OOM)• Same behavior as Low + Kill victim process• Victim process is chosen from Kernel

ss_lowmem_handler.c


43

13

• Other system events (Low battery, USB connection, Device change, MMC device) are also similar as low memory handler.– Handle system-level event for device

• e.g. – mount, and unmount, format event will be handled from system-server– Storage I/O will not be handled from system-server

Others


43

14

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

Inter-process communication


43

15

• light-weight notification library– using inotify mechanism

• alert filesystem event

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

heynoti (framework/appfw/heynoti)


43

16

• 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

• synoti_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


43

17

• 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)


43

18

• 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


43

19

• Device manager library for device control– LCD, display control (brightness, tone)– battery monitoring – haptic event access

Device manager


43

20

• Library that manages device node for each devices 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

libdevicenode


43

21

• Types of Sensors – Tizen supports individual plugin frameworks for these sensors:

• Accelerometer sensor • Gyroscope sensor • Proximity sensor • Motion sensor • Geomagnetic sensor • Light sensor

Sensor Framework


43

22

• 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.

• 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.

Sensor details


43

23

• Components of Sensor Framework – The Sensor framework provides a sensor server for creating plugins and a medium

through which the client applications are connected to the sensor hardware to exchange data. The sensor plugins retrieve data from sensor hardware and enable the client applications to use the data for specific requirements.

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

daemon through the sensor API library. An API library allows the application to access the sensor service. As shown in the below diagram, applications/middleware frameworks can have the sensor-framework client library in the process context.

– Sensor Server • The sensor server is a daemon which communicates uniquely to sensor drivers in the system

and dispatches sensor data to the application. The sensor server takes care of interacting with the sensor driver in hardware initialization, driver configuration, and data fetching, to manage all sensors on the platform.

• Type of plugins in sensor framework – Sensor Plugin

• Sensor plugins takes care of interacting with the sensor driver. Plug-ins process data from sensor drivers and communicate it to the sensor server.

– Processor• Active component (it has a thread) that processes data or makes events from a filter or from

sensor data. – Filter

• Passive component that converts sensor raw data to other types of data – Sensor

• Passive component that gets raw data from the kernel node

Sensor Framework details


43

24

App Framework


43

25App Framework Overview


43

26Tizen Core Application Types


43

27

• 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


43

28Appcore Internal callback


43

29

• Include appcore_common.h or appcore_efl.h

• fill appcore_ops for proper function pointers

• call appcore_efl_main when using EFL

Using appcore


43

30Application Life Cycle: State and Transitions


43

31Tizen GUI App Structure


43

32

• 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

Application Utility Library: AUL


43

33

• Open socket file• wait for recv() at

__launchpad_main_loop

AUL Daemon (launchpad)


43

34AUL Overall ARchitecture


43

35

– 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


43

36

• 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

AUL: Launch


43

37

• 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)


43

38App Service Overall Flow


43

39App Service Request


43

40

• 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


43

41

• 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


43

42

• 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


43

43

• “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 • http://seoz.egloos.com

References

Embedded Software Lab. @ SKKU 43 1 Tizen System / App Framework.

Documents

Transcript of Embedded Software Lab. @ SKKU 43 1 Tizen System / App Framework.