Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Digging Into Android System Services
Search
Dave Smith
September 16, 2016
Programming
8
1.4k
Digging Into Android System Services
Walkthrough of the architecture that the Android platform uses to expose services to applications.
Dave Smith
September 16, 2016
Tweet
Share
More Decks by Dave Smith
See All by Dave Smith
Android Security Features
devunwired
4
620
ConstraintLayout, Inside and Out
devunwired
21
1.6k
Flattening Layouts with Constraints
devunwired
3
260
Hello, Brillo: ELC Edition
devunwired
0
240
Mastering CoordinatorLayout Behaviors
devunwired
16
1.3k
Hello, Brillo
devunwired
1
1.9k
Google Proximity Beacons Overview
devunwired
4
220
Proximity Beacons and the Nearby API
devunwired
1
1.8k
Getting Your Act Together with CoordinatorLayout
devunwired
7
460
Other Decks in Programming
See All in Programming
Architecture Decision Record (ADR)
nearme_tech
PRO
1
690
[DroidKaigi 2024] Android ViewからJetpack Composeへ 〜Jetpack Compose移行のすゝめ〜 / From Android View to Jetpack Compose: A Guide to Migration
syarihu
1
630
Go1.23で入った errorsパッケージの小さなアプデ
kuro_kurorrr
2
390
『ドメイン駆動設計をはじめよう』中核の業務領域
masuda220
PRO
5
1k
Our Websites Need a Lifestyle Change, Not a Diet
ryantownsend
0
150
Developer Joy == Developer Productivity (really!)
hollycummins
1
220
Lessons by WebAssembly app in production on CDN Edge Computing Service
tetsuharuohzeki
0
210
API Platform for Laravel
dunglas
0
320
Method Swizzlingを行うライブラリにおけるマルチモジュール設計
yoshikma
0
120
Some more adventure of Happy Eyeballs
coe401_
2
190
いまから追い上げる、Jetpack Compose トレーニング
nyafunta9858
0
590
Pythonで改めて考える「クラス(class)」の使いどころ
os1ma
1
470
Featured
See All Featured
In The Pink: A Labor of Love
frogandcode
139
22k
Build your cross-platform service in a week with App Engine
jlugia
228
18k
It's Worth the Effort
3n
182
27k
Building Flexible Design Systems
yeseniaperezcruz
325
38k
4 Signs Your Business is Dying
shpigford
179
21k
Building a Modern Day E-commerce SEO Strategy
aleyda
36
6.8k
Fireside Chat
paigeccino
31
2.9k
Faster Mobile Websites
deanohume
304
30k
The Straight Up "How To Draw Better" Workshop
denniskardys
230
130k
Teambox: Starting and Learning
jrom
131
8.7k
Dealing with People You Can't Stand - Big Design 2015
cassininazir
363
22k
How STYLIGHT went responsive
nonsquared
93
5.1k
Transcript
Digging Into Android System Services Dave Smith, PE @devunwired
Why Are You Here? Trace AOSP Code Learn Platform Internals
Discover App Impact
Linux Kernel Hardware Abstraction Layer Native Services Runtime Application Framework
Applications
Linux Kernel Hardware Abstraction Layer Native Services Runtime Application Framework
Applications
Application System Server Manager Service
Application System Server Manager Service Application Manager Application Manager Application
Manager
Context.getSystemService(SERVICE_NAME)
ContextImpl SystemServiceRegistry Context AlarmManager NotificationManager LocationManager PowerManager Context.getSystemService(SERVICE_NAME)
package android.app; final class SystemServiceRegistry { ... static
{ ... registerService(Context.ACCOUNT_SERVICE, AccountManager.class, new CachedServiceFetcher<AccountManager>() { @Override public AccountManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService(Context.ACCOUNT_SERVICE); IAccountManager service = IAccountManager.Stub.asInterface(b); return new AccountManager(ctx, service); } }); ... registerService(Context.ALARM_SERVICE, AlarmManager.class, new CachedServiceFetcher<AlarmManager>() { @Override public AlarmManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService(Context.ALARM_SERVICE); IAlarmManager service = IAlarmManager.Stub.asInterface(b); return new AlarmManager(service, ctx); } }); ... } } SystemServiceRegistry.java
package android.app; final class SystemServiceRegistry { ... static
{ ... registerService(Context.ACCOUNT_SERVICE, AccountManager.class, new CachedServiceFetcher<AccountManager>() { @Override public AccountManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService(Context.ACCOUNT_SERVICE); IAccountManager service = IAccountManager.Stub.asInterface(b); return new AccountManager(ctx, service); } }); ... registerService(Context.ALARM_SERVICE, AlarmManager.class, new CachedServiceFetcher<AlarmManager>() { @Override public AlarmManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService(Context.ALARM_SERVICE); IAlarmManager service = IAlarmManager.Stub.asInterface(b); return new AlarmManager(service, ctx); } }); ... } } SystemServiceRegistry.java
Application System Server Manager Service
Binder IPC Application System Server Service Manager
Application System Server Manager Service Binder IPC AIDL Proxy Stub
Application System Server AlarmManager AlarmManagerService IAlarmManager IAlarmManager.Stub Binder IPC
IAlarmManager.aidl AlarmManager.java package android.app; ... public class AlarmManager
{ private final IAlarmManager mService; ... public void setTime(long millis) { try { mService.setTime(millis); } catch (RemoteException ex) { throw ex.rethrowFromSystemServer(); } } public void setTimeZone(String timeZone) { ... try { mService.setTimeZone(timeZone); } catch (RemoteException ex) { throw ex.rethrowFromSystemServer(); } } } package android.app; interface IAlarmManager { void set(...); boolean setTime(long millis); void setTimeZone(String zone); void remove(...); long getNextWakeFromIdleTime(); ... }
IAlarmManager.aidl AlarmManager.java package android.app; ... public class AlarmManager
{ private final IAlarmManager mService; ... public void setTime(long millis) { try { mService.setTime(millis); } catch (RemoteException ex) { throw ex.rethrowFromSystemServer(); } } public void setTimeZone(String timeZone) { ... try { mService.setTimeZone(timeZone); } catch (RemoteException ex) { throw ex.rethrowFromSystemServer(); } } } package android.app; interface IAlarmManager { void set(...); boolean setTime(long millis); void setTimeZone(String zone); void remove(...); long getNextWakeFromIdleTime(); ... }
package com.android.server; public class AlarmManagerService extends SystemService { ...
private final IBinder mService = new IAlarmManager.Stub() { @Override public boolean setTime(long millis) { getContext().enforceCallingOrSelfPermission( "android.permission.SET_TIME", "setTime"); ... } @Override public void setTimeZone(String tz) { getContext().enforceCallingOrSelfPermission( "android.permission.SET_TIME_ZONE", "setTimeZone"); ... } }; } AlarmManagerService.java IAlarmManager.aidl package android.app; interface IAlarmManager { void set(...); boolean setTime(long millis); void setTimeZone(String zone); void remove(...); long getNextWakeFromIdleTime(); ... }
Binder IPC Application Service Object
Binder IPC Application Service Object Object
public class MainActivity extends Activity implements LocationListener { @Override
protected void onResume() { super.onResume(); LocationManager manager = (LocationManager) getSystemService(LOCATION_SERVICE); manager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this); } @Override protected void onPause() { super.onPause(); LocationManager manager = (LocationManager) getSystemService(LOCATION_SERVICE); manager.removeUpdates(this); } @Override public void onLocationChanged(Location location) { ... } ... }
public class MainActivity extends Activity implements LocationListener { @Override
protected void onResume() { super.onResume(); LocationManager manager = (LocationManager) getSystemService(LOCATION_SERVICE); manager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this); } @Override protected void onPause() { super.onPause(); LocationManager manager = (LocationManager) getSystemService(LOCATION_SERVICE); manager.removeUpdates(this); } @Override public void onLocationChanged(Location location) { ... } ... }
Application System Server Manager Service
Application System Server Manager Service Service Manager Stub Stub
Application System Server Manager Service Service Manager IBinder Stub IBinder
Application System Server Manager Service Service Manager Proxy Stub IBinder
$ adb shell service list Found 116 services: 0 carrier_config:
[com.android.internal.telephony.ICarrierConfigLoader] 1 phone: [com.android.internal.telephony.ITelephony] 2 isms: [com.android.internal.telephony.ISms] 3 iphonesubinfo: [com.android.internal.telephony.IPhoneSubInfo] 4 simphonebook: [com.android.internal.telephony.IIccPhoneBook] 5 isub: [com.android.internal.telephony.ISub] 6 telecom: [com.android.internal.telecom.ITelecomService] 7 contexthub_service: [android.hardware.location.IContextHubService] 8 dns_listener: [android.net.metrics.IDnsEventListener] 9 connectivity_metrics_logger: [android.net.IConnectivityMetricsLogger] 10 imms: [com.android.internal.telephony.IMms] 11 media_projection: [android.media.projection.IMediaProjectionManager] 12 launcherapps: [android.content.pm.ILauncherApps] 13 shortcut: [android.content.pm.IShortcutService] 14 fingerprint: [android.hardware.fingerprint.IFingerprintService] 15 trust: [android.app.trust.ITrustManager] 16 media_router: [android.media.IMediaRouterService] 17 media_session: [android.media.session.ISessionManager] 18 restrictions: [android.content.IRestrictionsManager] 19 print: [android.print.IPrintManager] 20 graphicsstats: [android.view.IGraphicsStats] ...
package android.app; final class SystemServiceRegistry { ... static
{ ... registerService(Context.ACCOUNT_SERVICE, AccountManager.class, new CachedServiceFetcher<AccountManager>() { @Override public AccountManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService(Context.ACCOUNT_SERVICE); IAccountManager service = IAccountManager.Stub.asInterface(b); return new AccountManager(ctx, service); } }); ... registerService(Context.ALARM_SERVICE, AlarmManager.class, new CachedServiceFetcher<AlarmManager>() { @Override public AlarmManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService(Context.ALARM_SERVICE); IAlarmManager service = IAlarmManager.Stub.asInterface(b); return new AlarmManager(service, ctx); } }); ... } } SystemServiceRegistry.java
package android.app; final class SystemServiceRegistry { ... static
{ ... registerService(Context.ACCOUNT_SERVICE, AccountManager.class, new CachedServiceFetcher<AccountManager>() { @Override public AccountManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService(Context.ACCOUNT_SERVICE); IAccountManager service = IAccountManager.Stub.asInterface(b); return new AccountManager(ctx, service); } }); ... registerService(Context.ALARM_SERVICE, AlarmManager.class, new CachedServiceFetcher<AlarmManager>() { @Override public AlarmManager createService(ContextImpl ctx) { IBinder b = ServiceManager.getService(Context.ALARM_SERVICE); IAlarmManager service = IAlarmManager.Stub.asInterface(b); return new AlarmManager(service, ctx); } }); ... } } SystemServiceRegistry.java
package com.android.server; import android.content.Context; public final class SystemServer
{ ... ConnectivityServicer connectivity = new ConnectivityService( context, networkManagement, networkStats, networkPolicy); ServiceManager.addService(Context.CONNECTIVITY_SERVICE, connectivity); ... LocationManagerService location = new LocationManagerService(context); ServiceManager.addService(Context.LOCATION_SERVICE, location); ... } SystemServer.java
@devunwired +DaveSmithDev milehighandroid.com wiresareobsolete.com