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kotlinlang

Hi, I need a CoroutineDispatcher on Android that will make `delay` wait for given real time, not CPU time. I'm assuming that default implementation doesn't take CPU sleep into account, I'm I right? If during 5min delay CPU sleeps for 15 min, will delay effectively take 20min?

I don't expect delay expiring to wake the CPU, just that it executes soon after CPU wakes from sleep if needed.

`delay` depends on the Dispatcher, so it probably differs if you're talking about `Dispatcher.Main` vs `Dispatcher.Default`. iirc `Main` tends to use the platform's waiting utilities, so on android that's `Handler`: <https://github.com/Kotlin/kotlinx.coroutines/blob/master/ui/kotlinx-coroutines-android/src/HandlerDispatcher.kt#L139>

`postDelayed` says it uses <https://developer.android.com/reference/android/os/SystemClock.html#uptimeMillis()>

I think `Default` uses `System.nanoTime()` on android, which probably is CPU time as well

you probably should use `suspendCancellableCoroutine` in addition to `AlarmManager` + <https://developer.android.com/reference/android/app/AlarmManager.html#ELAPSED_REALTIME> , or if you need it more ingrained, write a new dispatcher on top of that.

AlarmManager seems like an overkill, but I'm not sure how to benchmark it against some alternative

the only alternative I could think of (haven't used android a bunch) would be to spin on <https://developer.android.com/reference/android/os/SystemClock.html#elapsedRealtime()> , which I would think is much less efficient than AlarmManager

Depending on how precise you need this job to run I'd recommend either AlarmManager (for precision at the cost of battery life) or WorkManager (for a more optimized yet less precisely timed execution)

Can you give more details about what you want to accomplish with this task?

I'm doing some minute-by-minute stats of data flowing though my VPN. I was thinking I can either check the time for each data packet (maybe over 10k times a second) or I can have a 1 min timer to do the same. Only issue is that I can't get proper timer without some heavy IPC APIs.