Power management has become an essential part of any mobile operating system, considering the increasing demand for longer battery life in smartphones. Android, being the most widely used mobile platform, has been constantly evolving its power management techniques to provide a better user experience. In this article, we will delve into two advanced techniques for power management in Android – Doze mode and App Standby.
Doze mode was introduced in Android 6.0 (Marshmallow) and has been further improved in subsequent versions. It is a power-saving feature that aims to extend the battery life by putting the device into a deep sleep state when it is not in use. This mode kicks in when the device is unplugged, stationary, and the screen is turned off for a period of time. In Doze mode, most background processes, network activity, and wake locks are restricted, thus reducing battery consumption.
So how does Doze mode work? When the device enters Doze mode, it first enters a light doze state where it conserves power by deferring CPU activity and network access. If the device stays idle for an extended period, it enters a deeper doze state where even more restrictions are applied. The device periodically wakes up from deep doze mode to perform tasks such as syncing data and processing pending pending alarms. However, the frequency of these wake-ups is reduced, resulting in improved battery life without compromising functionality.
As an app developer, it is crucial to understand how your app behaves in Doze mode. By default, apps that target Android API level 23 or higher are automatically optimized for Doze mode. This means that a background process will not be allowed to run unless the device is charging, the user explicitly launches the app, or the app has high-priority tasks such as a foreground service. Therefore, it is essential to optimize your app to work efficiently in Doze mode.
One way to do this is by using the AlarmManager class to schedule tasks. In Doze mode, the system batches non-high priority alarms together and delays them, reducing the frequency of wake-ups. To ensure that your alarm fires in Doze mode, you can use setExactAndAllowWhileIdle() or setAndAllowWhileIdle() methods. These methods have restrictions on how frequently they can be set, so use them sparingly.
Another technique for optimizing your app in Doze mode is by using the JobScheduler API. Unlike the AlarmManager, JobScheduler allows the system to batch tasks from different apps and execute them together, conserving battery life. You can schedule a job using the schedule() method, specifying the desired execution criteria such as network access and charging state. It is recommended to use this API for tasks that do not require immediate execution.
Apart from Doze mode, Android also introduced App Standby to further improve power management. App Standby puts apps into a lower-priority state when they have not been used for an extended period. In this state, the app’s network access and background processing are restricted, resulting in reduced battery consumption. However, high-priority tasks such as incoming calls, alarms, and Firebase Cloud Messaging (FCM) can still wake the app.
As an app developer, you can monitor your app’s standby state using the isIdle() method in the PackageManager class. If the app is in standby mode, you can use the setAppStandbyBucket() method to specify the desired standby bucket. This allows your app to receive certain restrictions and optimizations based on its usage patterns. For example, if your app is in the “working set” bucket, it will receive fewer restrictions compared to apps in the “rare” bucket.
In conclusion, Doze mode and App Standby are advanced techniques for power management in Android that can significantly improve battery life. As an app developer, it is crucial to understand how these modes work and optimize your app accordingly. By using the AlarmManager and JobScheduler APIs for scheduling tasks and monitoring your app’s standby state, you can ensure that your app consumes minimal battery while maintaining its functionality. So, the next time you develop an app for Android, be sure to consider these advanced power management techniques for a better user experience.