ContentResolver.addPeriodicSync interval round up

Question

My sync adapter does work perfectly well except for one little thing which bugs the sh*t out of me for the last few hours... For my app i want the sync adapter to run with a

Answer 1

The problem here is the wrong documentation in the android source code.

The real values are:

• Starting with Froyo (API 8) which first introduced addPeriodicSync method, there wasn't a minimum time interval, source here and here (even if internally each retry has to wait a minimum of 30 seconds).
• Starting with KitKat (API 19) the minumum interval has been set to 1 minute, source here
• Starting from Nougat (API 24) the minimum interval is 15 minutes, source here, here and here

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Additional info:

• Starting from Marshmallow (API 23), the periodic sync frequency it's also affected by doze mode and additional OS battery optimizations

PS: The documentation of addPeriodicSync(...) is wrong about pollFrequency param before API 24, I've opened an issue waiting Google to fix it.

Answer 2

It seems to be that it is not possible to add a period sync with an interval lesser than 60 seconds. (Or least from 4.4 and higher.)

https://android.googlesource.com/platform/frameworks/base/+/kitkat-mr1-release/services/java/com/android/server/content/ContentService.java

if (request.isPeriodic()) {
    mContext.enforceCallingOrSelfPermission(
        Manifest.permission.WRITE_SYNC_SETTINGS,
        "no permission to write the sync settings");
    if (runAtTime < 60) {
        Slog.w(TAG, "Requested poll frequency of " + runAtTime
            + " seconds being rounded up to 60 seconds.");
        runAtTime = 60;
    }
    PeriodicSync syncToAdd =
        new PeriodicSync(account, provider, extras, runAtTime, flextime);
    getSyncManager().getSyncStorageEngine().addPeriodicSync(syncToAdd, userId);
}

Answer 3

W/ContentService: Requested poll frequency of 300 seconds being rounded up to 900s.

It seems that on Android 7 and 8 the minimum frequency is 15 min. Till Android 6 we had a round up to 60 sec, which is decent.

I also noticed that we have a note on pollFrequency that 1h is minimum.

pollFrequency long: the amount of time in seconds... A minimum period of 1 hour is enforced.

It seems pretty inconsistent to me.