Android Doze mode impact on existing code for developers

There are several scenarios developers need to concern themselves with following the introduction of Doze Mode. Alarms that need to fire off at an exact time can still do so with the AlarmManager using its setAndAllowWhileIdle() or setExactAndAllowWhileIdle() methods. Imagine an alarm clock app that did not wake its user in the morning due to Doze Mode!

Another scenario would involve important incoming notifications, such as texts, emails or even tweets, if that is what users find important. For those cases, developers will need to use GCM with high-priority messages.

Notice the “priority” : “high” attribute-value pair below.

{
  "to" : "instance-token",
  "priority" : "high",
  "notification" : {
    "body" : "yeah.....",
    "title" : "title1",
    "icon" : "http://icon.com/icon.ng",
  },
  "data" : {
    "contents" : "https://someurl.com"
  }
}

Doze Mode

Doze Mode was introduced in Android Marshmallow as a way to minimize battery drain while a user has been away from their device for a period of time. Doze Mode is automatically enabled on devices running Android API level 23 and higher. It is not a scheduler that developers need to implement. Rather, it affects the other schedulers we have already discussed.

Doze Mode is enabled after a period of time under these conditions: The user’s screen has been off, the device has been stationary and the device has not been charging. When in Doze Mode, network access is suspended, the system ignores wake locks and standard alarms are deferred, including the running of Sync Adapters and JobSchedulers. There are maintenance windows that infrequently occur to allow all of these schedulers within the system to run at once, therefore preserving battery through infrequent and grouped network calls.

Notice that maintenance windows occur less frequently the longer the device is dozing. Once the user moves the device, turns on the screen or connects to a charger, normal activity resumes. You could imagine the battery benefits while users sleep or leave their phone unattended for a long period of time.

How to interrupt Doze Mode

Applications with core functionality requiring work to schedule outside of the Doze Mode maintenance windows can be whitelisted. Such whitelisting requires a special permission, and Google Play policies allow it only in certain cases.

These are currently the only scenarios in which developers can interrupt Doze Mode outside of the maintenance window. This isn’t usually a problem, since most scheduling should involve efficient, infrequent scheduling, but it is something to be aware of.

How to test Doze Mode behaviour on app

1. Force the system into idle mode by running the following command:

$ adb shell dumpsys deviceidle force-idle

2. When ready, exit idle mode by running the following command:

$ adb shell dumpsys deviceidle unforce