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
1.3k
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
570
ConstraintLayout, Inside and Out
devunwired
21
1.6k
Flattening Layouts with Constraints
devunwired
3
240
Hello, Brillo: ELC Edition
devunwired
0
230
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
450
Other Decks in Programming
See All in Programming
ONE WEDGE_Company_Information
1wedge
0
170
htmx is fun!
codehex
2
190
Go1.22からの疑似乱数生成器について/go-122-pseudo-random-generator
convto
1
160
どうしてこうなった命名集 ~🔥編~ / OOC 2024 LT
pictiny
4
2.8k
OpenTelemetry のサービスという概念について
azukiazusa1
1
390
Honoとhtmx
yusukebe
6
1.2k
マイ隙間家具OSSたちのご紹介
karupanerura
2
150
せっかくモデル図描くのなら、嬉しいことが多い方がいいよね!
kuboaki
1
1.7k
孤独のCTOグルメという やや奇抜な企画をやった目的と効果
shoheimitani
3
1k
LLMチャットボットのアプリケーション設計Tips
os1ma
4
660
RubyVM を PHP で実装する 〜Hello World を出力するまで〜
memory1994
PRO
1
490
Deno に Web 標準 API を実装する / Implementing Web Standard API to Deno
petamoriken
0
350
Featured
See All Featured
Ruby is Unlike a Banana
tanoku
95
10k
Teambox: Starting and Learning
jrom
126
8.4k
"I'm Feeling Lucky" - Building Great Search Experiences for Today's Users (#IAC19)
danielanewman
219
21k
Understanding Cognitive Biases in Performance Measurement
bluesmoon
6
950
Automating Front-end Workflow
addyosmani
1353
200k
Raft: Consensus for Rubyists
vanstee
130
6.2k
Bootstrapping a Software Product
garrettdimon
PRO
302
110k
Building Your Own Lightsaber
phodgson
97
5.6k
Designing with Data
zakiwarfel
94
4.8k
5 minutes of I Can Smell Your CMS
philhawksworth
199
19k
The Cult of Friendly URLs
andyhume
73
5.6k
Practical Orchestrator
shlominoach
180
9.7k
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