A guide to Android Background Work

It’s hard to keep track each year of the best practices to perform background work on Android: behavior changes targeting new SDK versions, new permissions, new policies, updated tools, and libraries.

This talk will examine the most popular types of background work developers could need to run and suggest the appropriate tools, along with some tips learned from developing production apps.

Particular attention will be dedicated to WorkManager’s new features and recent platform behavior changes that impact this topic.

After attending this talk you’ll know:
– New rules and behavior changes of most newer Android versions regarding background work;
– What Immedate, Long Running, and Deferrable work are and which tools to use for them;
– New features in WorkManager’s latest releases;
– Real-life experiences with background jobs consistency around different smartphone vendors;

Transcript

1. Appdevcon 2024 A guide to Android Background Work Paolo Rotolo
2. Paolo Rotolo • Android Dev @ Nextome • Open source contributor • Piano player
3. Different Types of Work
4. Different Types of Work Immediate Send a message Start a payment flow Upload a photo …
5. Different Types of Work Immediate Long Running Bulk uploads Location tracking Listen to music …
6. Different Types of Work Immediate Long Running Deferrable Log upload Database sync Storage optimisation …
7. Different Types of Work Immediate Long Running Deferrable
8. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent
9. Persistent Work Global scope
10. Persistent Work Global scope Process Death
11. Persistent Work Global scope Process Death Reboot
12. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent
13. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent
14. Immediate Impersistent Work class ProfileViewModel: ViewModel() { fun loadPhotos() { viewModelScope.launch { fetchUserPhotos() } }
15. Async Work class ProfileViewModel: ViewModel() { fun loadPhotos() { viewModelScope.launch { fetchUserPhotos() } }
16. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent Coroutines
17. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent WorkManager Coroutines WorkManager / Foreground Services WorkManager
18. WorkManager “ The recommended library for persistent work”
19. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent WorkManager Coroutines WorkManager / Foreground Services WorkManager
20. Different Types of Work Deferrable WorkManager
21. WorkManager class UploadLogsWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { try { uploadLogs() } catch(e: HttpException) { return if (e.code == 500) { Result.retry() } else{ Result.failure() } } return Result.success() }
22. WorkManager class UploadLogsWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { try { val workManager = WorkManager .getInstance(applicationContext) val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).build() workManager.enqueue(workRequest)
23. val workManager = WorkManager .getInstance(applicationContext) val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).build() workManager.enqueue(workRequest)
24. val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).build() repeatInterval repeatInterval repeatInterval can run work can run work can run work
25. Schedule exact alarms AlarmManager fun setExact (int type, long triggerAtMillis, PendingIntent operation)
26. Schedule exact alarms AlarmManager fun setExact (int type, long triggerAtMillis, PendingIntent operation) - Use only when exact-time delivery is required
27. Schedule exact alarms AlarmManager fun setExact (int type, long triggerAtMillis, PendingIntent operation) - Use only when exact-time delivery is required - SDK >= 31 will require SCHEDULE_EXACT_ALARM permission
28. val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).build() repeatInterval repeatInterval repeatInterval can run work can run work can run work
29. val workManager = WorkManager .getInstance(applicationContext) val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).build() workManager.enqueue(workRequest)
30. val workManager = WorkManager .getInstance(applicationContext) val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).build() val uniqueWorkName = "uploadLogWork" workManager.enqueueUniquePeriodicWork(uniqueWorkName, ExistingPeriodicWorkPolicy.KEEP, workRequest)
31. val uniqueWorkName = "uploadLogWork" workManager.enqueueUniquePeriodicWork(uniqueWorkName, ExistingPeriodicWorkPolicy.KEEP, workRequest) ExistingPeriodicWorkPolicy.KEEP ExistingPeriodicWorkPolicy.REPLACE
32. ExistingPeriodicWorkPolicy.KEEP ExistingPeriodicWorkPolicy.CANCEL_AND_REENQUEUE Starting from… WorkManager 2.8.0 (Feb 2023)
33. ExistingPeriodicWorkPolicy.KEEP ExistingPeriodicWorkPolicy.CANCEL_AND_REENQUEUE ExistingPeriodicWorkPolicy.UPDATE Starting from… WorkManager 2.8.0 (Feb 2023) Preserves enqueue time
34. val workManager = WorkManager .getInstance(applicationContext) val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).build() val uniqueWorkName = "uploadLogWork" workManager.enqueueUniquePeriodicWork(uniqueWorkName, ExistingPeriodicWorkPolicy.KEEP, workRequest)
35. val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).build() val uniqueWorkName = "uploadLogWork" workManager.enqueueUniquePeriodicWork(uniqueWorkName, ExistingPeriodicWorkPolicy.KEEP, workRequest) Starting from… WorkManager 2.9.0 (Nov 2023)
36. val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).setNextScheduleTimeOverride(newTimeInMillis).build() val uniqueWorkName = "uploadLogWork" workManager.enqueueUniquePeriodicWork(uniqueWorkName, ExistingPeriodicWorkPolicy.UPDATE, workRequest) Starting from… WorkManager 2.9.0 (Nov 2023)
37. val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).setNextScheduleTimeOverride(newTimeInMillis).build() WorkManager 2.9.0 (Nov 2023) newTimeInMillis repeatInterval repeatInterval can run work can run work can run work
38. val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).setNextScheduleTimeOverride(newTimeInMillis).build() val uniqueWorkName = "uploadLogWork" workManager.enqueueUniquePeriodicWork(uniqueWorkName, ExistingPeriodicWorkPolicy.UPDATE, workRequest) WorkManager 2.9.0 (Nov 2023)
39. workManager.getWorkInfosForUniqueWorkLiveData(uniqueWorkName) val workRequest = PeriodicWorkRequestBuilder<UploadLogsWorker>( repeatInterval = 24, repeatIntervalTimeUnit = TimeUnit.HOURS ).setNextScheduleTimeOverride(newTimeInMillis).build() val uniqueWorkName = "uploadLogWork" workManager.enqueueUniquePeriodicWork(uniqueWorkName, ExistingPeriodicWorkPolicy.UPDATE, workRequest)
40. Starting from… WorkManager 2.9.0 (Nov 2023) workManager.getWorkInfosForUniqueWorkLiveData(uniqueWorkName)
41. workManager.getWorkInfosForUniqueWorkFlow(uniqueWorkName).collect{ } Starting from… WorkManager 2.9.0 (Nov 2023)
42. workManager.getWorkInfosForUniqueWorkFlow(uniqueWorkName).collect{ val workInfo = it.first() workInfo.nextScheduleTimeMillis } Starting from… WorkManager 2.9.0 (Nov 2023)
43. workManager.getWorkInfosForUniqueWorkFlow(uniqueWorkName).collect{ val workInfo = it.first() workInfo.nextScheduleTimeMillis } Starting from… WorkManager 2.9.0 (Nov 2023) estimated time
44. Different Types of Work Deferrable WorkManager
45. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent WorkManager Coroutines WorkManager / Foreground Services WorkManager
46. Different Types of Work Long Running WorkManager / Foreground Services (> 10 minutes)
47. class LocalizationWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { while (true) { val position = computeUserPosition() sendPositionToBackend(position) delay(1.minutes) } return Result.success() }
48. How long will my Worker run in background?
49. WorkManager under the hood
50. WorkManager under the hood API 23+ API 14-22 Custom AlarmManager + BroadcastReceiver JobScheduler
51. Why don’t we use JobScheduler directly?
53. WorkManager under the hood API 23+ API 14-22 Custom AlarmManager + BroadcastReceiver JobScheduler + GreedyScheduler
54. JobScheduler “In Android version LOLLIPOP, jobs had a maximum execution time of one minute. Starting with Android version M and ending with Android version R, jobs had a maximum execution time of 10 minutes. Starting from Android version S, jobs will still be stopped after 10 minutes if the system is busy or needs the resources, but if not, jobs may continue running longer than 10 minutes.”
55. it’s not so easy
56. it’s not so easy meet App Standby Buckets
57. Starting from Android 9 (API 28) - Active - Working Set - Frequent - Rare - Restricted No restriction 10 minutes every 2h 10 minutes every 8h 10 minutes every 24h Once for day Jobs Bucket
58. Introducing Foreground Services
59. class LocalizationWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { while (true) { val position = computeUserPosition() sendPositionToBackend(position) delay(1.minutes) } return Result.success() }
60. class LocalizationWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { setForeground(createForegroundInfo()) while (true) { val position = computeUserPosition() sendPositionToBackend(position) delay(1.minutes) } return Result.success() }
61. private fun createForegroundInfo(): ForegroundInfo { val title = "Example title" // Pending Intent to cancel the worker val intent = WorkManager.getInstance(applicationContext) .createCancelPendingIntent(getId()) createNotificationChannel("channel_id", "Example channel") val notification = NotificationCompat.Builder(applicationContext, "CHANNEL ID") .setContentTitle(title) .setTicker(title) .setContentText("Running in background ... ") .setSmallIcon(R.mipmap.ic_launcher) .setOngoing(true) .addAction(android.R.drawable.ic_delete, "STOP", intent) .build() return ForegroundInfo(42, notification) } private val notificationManager = appContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager @TargetApi(Build.VERSION_CODES.O) private fun createNotificationChannel( channelId: String,
62. class LocalizationWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { setForeground(createForegroundInfo()) while (true) { val position = computeUserPosition() sendPositionToBackend(position) delay(1.minutes) } return Result.success() }
63. Foreground Services Limitations and recent API Changes
64. Starting from… Android 10 (Target API 29) <application> <service android:name="androidx.work.impl.foreground.SystemForegroundService" android:foregroundServiceType="location" tools:node="merge" />
65. Starting from… Android 14 (Target API 34) <application> <service android:name="androidx.work.impl.foreground.SystemForegroundService" android:foregroundServiceType="location" tools:node="merge" /> <uses-permission android:name="android.permission.FOREGROUND_SERVICE_LOCATION" /> Mandatory to specify at least one type
66. Starting from… Android 14 (Target API 34) camera connectedDevice dataSync health location mediaPlayback mediaProjection microphone phoneCall remoteMessaging shortService specialUse systemExempted
67. Starting from… Android 13 (Target API 33) TaskManager
68. Apps in restricted bucket don’t schedule Foreground Services Starting from… Android 12 (Target API 31)
69. Apps in restricted bucket don’t schedule Foreground Services ForegroundServices can not be launched from background Starting from… Android 12 (Target API 31)
70. ForegroundServices can not be launched from background unless...
71. ForegroundServices can not be launched from background unless... App uses CompanionDeviceManager with associated permissions
72. ForegroundServices can not be launched from background unless... App uses CompanionDeviceManager with associated permissions App receives a Geofencing or ActivityRecognition event
73. ForegroundServices can not be launched from background unless... App uses CompanionDeviceManager with associated permissions App receives a Geofencing or ActivityRecognition event App receives an High Priority FCM notification
74. App receives an High Priority FCM notification - High Priority FCM should be used for time-sensitive, user-facing features - App Standby Buckets will not regulate app HP FCM Quotas - Apps that do not successfully post notifications in response to HP FCMs may see messages demoted
75. App receives an High Priority FCM notification - High Priority FCM should be used for time-sensitive, user-facing features - App Standby Buckets will not regulate app HP FCM Quotas - Apps that do not successfully post notifications in response to HP FCMs may see messages demoted
76. ForegroundServices can not be launched from background unless... App uses CompanionDeviceManager with associated permissions App receives a Geofencing or ActivityRecognition event App receives an High Priority FCM notification
77. ForegroundServices can not be launched from background unless... App uses CompanionDeviceManager with associated permissions App receives a Geofencing or ActivityRecognition event App receives an High Priority FCM notification App receives ACTION_BOOT_COMPLETED, ACTION_TIMEZONE_CHANGED System apps Apps with device owners and profile owners permissions Apps with SYSTEM_ALERT_WINDOW permission App is current input method App invokes an Exact Alarm to complete an action the user request User performs an action on a UI element related to the app
78. ForegroundServices can not be launched from background unless... User turns off Battery Optimisations for the app
79. When to use ForegroundServices directly
80. When to use ForegroundServices directly Media Playing Activity Tracking Location Sharing Voice or Video Calls
81. Starting from… Android 14 (Target API 34) val networkRequestBuilder = NetworkRequest.Builder() .addCapability(NET_CAPABILITY_INTERNET) .addCapability(NET_CAPABILITY_NOT_METERED) // Add or remove capabilities based on your requirements .build() val jobInfo = JobInfo.Builder() // ... .setUserInitiated(true) .setRequiredNetwork(networkRequestBuilder.build()) .setEstimatedNetworkBytes(1024 * 1024 * 1024) // ... .build() Migrate ForegroundServices to UserInitiated Data Transfer Jobs
82. Starting from… Android 14 (Target API 34) Migrate ForegroundServices to UserInitiated Data Transfer Jobs or use WorkManager!
83. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent WorkManager Coroutines WorkManager / Foreground Services WorkManager
84. Different Types of Work Immediate Persistent Impersistent WorkManager Coroutines
85. class SendMessageWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { try { sendMessage(inputData) } catch (e: NetworkException) { return Result.retry() } return Result.success() }
86. Expedited Work
87. Expedited Work Importance
88. Expedited Work Importance Speed
89. Expedited Work Importance Speed Quotas
90. Expedited Work Importance Speed Quotas Power Management
91. Expedited Work Importance Speed Quotas Power Management Latency
92. class SendMessageWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { try { sendMessage(inputData) } catch (e: NetworkException) { return Result.retry() } return Result.success() }
93. class SendMessageWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { val request = OneTimeWorkRequestBuilder<SendMessageWorker>() .build() workManager.enqueue(request)
94. class SendMessageWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { val request = OneTimeWorkRequestBuilder<SendMessageWorker>() .setExpedited(OutOfQuotaPolicy.RUN_AS_NON_EXPEDITED_WORK_REQUEST) .build() workManager.enqueue(request)
95. class SendMessageWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { try { sendMessage(inputData) } catch (e: NetworkException) { return Result.retry() } return Result.success() } workManager.enqueue(request)
96. class SendMessageWorker( appContext: Context, params: WorkerParameters, ) : CoroutineWorker(appContext, params) { override suspend fun getForegroundInfo(): ForegroundInfo { return createForegroundInfo() } override suspend fun doWork(): Result { try { sendMessage(inputData) } catch (e: NetworkException) { return Result.retry() } workManager.enqueue(request)
97. Expedited Work Android 12+ ExpeditedWork < Android 12 Foreground Service under the hood
98. Different Types of Work Immediate Long Running Deferrable Persistent Impersistent WorkManager Coroutines WorkManager / Foreground Services WorkManager
99. Debugging WorkManager
100. workManager .getWorkInfosForUniqueWorkFlow(workName) .collect { it.forEach { if (it.runAttemptCount > 0 && it.state = = WorkInfo.State.ENQUEUED) { log(it.stopReason) } } } Starting from… WorkManager 2.9.0-alpha02
101. override suspend fun doWork(): Result { try { sendMessage(inputData) } catch (e: NetworkException) { return Result.retry() } return Result.success() } Starting from… WorkManager 2.9.0-alpha02
102. override suspend fun doWork(): Result { logLastStoppedReason(stopReason) try { sendMessage(inputData) } catch (e: NetworkException) { return Result.retry() } return Result.success() } Starting from… WorkManager 2.9.0-alpha02
103. STOP_REASON_NOT_STOPPED STOP_REASON_CANCELLED_BY_APP STOP_REASON_PREEMPT STOP_REASON_TIMEOUT STOP_REASON_DEVICE_STATE STOP_REASON_CONSTRAINT_BATTERY_NOT_LOW STOP_REASON_CONSTRAINT_CHARGING STOP_REASON_CONSTRAINT_CONNECTIVITY STOP_REASON_CONSTRAINT_DEVICE_IDLE STOP_REASON_CONSTRAINT_STORAGE_NOT_LOW STOP_REASON_QUOTA STOP_REASON_BACKGROUND_RESTRICTION STOP_REASON_APP_STANDBY STOP_REASON_USER STOP_REASON_SYSTEM_PROCESSING STOP_REASON_ESTIMATED_APP_LAUNCH_TIME_CHANGED Starting from… WorkManager 2.9.0-alpha02
105. But wait, there’s more! meet OEMs customisations
109. Thank you! Questions?
110. Appdevcon 2024 A guide to Android Background Work Paolo Rotolo