Positioning "ForegroundServiceDidNotStartInTimeException & RemoteServiceException" of MediaSessionService

[xueluwei1]

Version

Media3 main branch

More version details

No response

Devices that reproduce the issue

Devices: samsung, realme, HUAWEI ...
Android version: 8.1, 9, 10, 11, 12 ...

Devices that do not reproduce the issue

No response

Reproducible in the demo app?

Not tested

Reproduction steps

1.Build.VERSION.SDK_INT >= 26
2.Play or some action triggered the "onUpdateNotification" funtion of MediaSessionService class and "updateNotification" funtion of MediaNotificationManager


3.Checking code made "boolean startInForegroundRequired = true"

4.Then called the system funtion "ContextCompat.startForegroundService"


5.And an amount of time later, service still running and not completed to call funtion "Util.setForegroundServiceNotification"
6.Finally we got the ForegroundServiceDidNotStartInTimeException on android S or later, and RemoteServiceException on older android versions

Expected result

Expected: You should call "context.startService" instead of "ContextCompat.startForegroundService"

Reason: The "ContextCompat.startForegroundService" funtion calls "startForegroundService" on version 26 and later, so cause these Exceptions. Actually, if you want MediaSessionService be a forground service, just call your "Util.setForegroundServiceNotification" funtion, and start by "context.startService". So that, we will not limited by the "startForegroundService" funtion, and no "ForegroundServiceDidNotStartInTimeException & RemoteServiceException" anymore.

This is the explain:

Actual result

we got "ForegroundServiceDidNotStartInTimeException & RemoteServiceException" crash in extension class of MediaSessionService:

Media

Not applicable

Bug Report

• You will email the zip file produced by adb bugreport to android-media-github@google.com after filing this issue.

[tianyif]

Hi @xueluwei1,

When playback starts or resumes, we need to start a foreground service, so that the system will always keep it running. However at this point, the app can usually be in the background state, thus the problem in front of us is - to start a foreground service from the background.

As the Android version evolves, the complication increases:

• Before Android 8 (API 26), the usual way to create a foreground service was to create a background service, then promote that service to the foreground, which corresponds to the your suggestion that to call Context.startService first, then call Service.startForeground.
• From Android 8 onwards, the system doesn't allow a background app to create a background service. For this reason, Android 8.0 introduces the new method startForegroundService() to start a new service in the foreground. The startForegroundService method works as a promise to the system that the service will definitely be promoted to foreground (by Service.startForeground) soon.

Therefore, we have to use startForegroundService. Please also see https://developer.android.com/about/versions/oreo/background#services for more details.

I'm not sure if there is something wrong inside the startForegroundService which delays the Service.startForeground or the extended implementation of MediaSessionService makes this happen. Do you have any reliable repro steps on demo-session app?

[xueluwei1]

No error in startForegroundService or MediaSessionService, maybe other code block main thread few second(like directly sleep 10s after call startForegroundService), and cause timeout. Call "context.startService" instead of "ContextCompat.startForegroundService" just to avoid the countdown and excption of timeout.
If you want start a foreground service(without having bound services or one foreground service) after few minute, startForegroundService function is right code.
And some tips:

Thanks for your answers.