This stuff drives me so mad. I recently have noticed higher than usual over-night drain on my phone and decided to investigate a bit. So I connected my phone to my machine, closed out all the apps waited a few seconds and ran adb shell top with a few parameters to see what is actually running.

And would you look at that, despite the phone telling me that nothing is running at all, the microsoft copilot, ebay kleinanzeigen (a german craigslist), google photos and google search either have not been closed or somehow started themselves. Also I have not received any notifications for these Apps in the last few seconds.

First of all, how are these Apps even doing it? With the two Google Apps I kinda get it, since they are System Apps, but in the case of ebay Kleinanzeigen and microsoft copilot it makes 0 sense since they are regular 3rd party Apps. How can they bypass seemingly all optimizations and start themselves (I haven’t used the Microsoft copilot app in months). Also is there any way to prevent this from happening or at the very least get some kind of summary how often these Apps ran in the background. Sadly the Android battery information page is totally useless. With many of these Apps I don’t care about notifications or anything and I never want them to run after I close them in the task manager.

  • Skull giver@popplesburger.hilciferous.nlEnglish
    38·
    2 months ago

    Android starts apps whenever a broadcast receiver for them gets triggered, unless the app crashed. Broadcast receivers can be messages exchanged between apps, connection events, battery charge events, you name it. Anything the OS might want to update an app for may cause a broadcast event. You cannot disable this mechanism; it’s the reason Android can put apps to sleep for days and still have them respond to important events as if they’re constantly running in the background without actually wasting any CPU on them.

    Most of the time, you don’t want to kill these background tasks. If they’re doing something for more than a few seconds, they’ll need to show a notification (though you won’t see that if you’ve hidden notifications from the app). Killing them will only make the phone restart them the next time an event they’re subscribed to gets triggered, which will cost you CPU time. Force stopping apps may stop services from randomly restarting, but if a notification comes in, the app may get started again.

    To figure out battery drain, check the battery stats in the settings first. That should show you what apps have been active in the foreground/background for how long.

    If that fails, you can start doing a deep dive into Battery Historian and its successors.

    Also make sure you exit any terminal sessions on your phone, if you use them, because terminal emulators often keep a wakelock, which might let the screen turn off but leave the phone running (so the commands don’t get killed when the phone goes to sleep).

    Based on the screenshot you showed, most of the CPU time seems to have gone into the Android system itself (system_server, your launcher, and so on). If you use any widgets, try removing those. Maybe also check if the launcher throws any errors. A simple adb logstat *:E should give a (long) overview of crashes and errors your phone is running into. Some of them may be unimportant, others could be the reason your phone got drained.

    • Avid Amoeba@lemmy.caEnglish
      6·
      2 months ago

      In addition, apps schedule background work through WorkManager or JobScheduler or AlarmManager. Those can wake the app up at specific times designated to do this work. E.g. every X minutes when the screen is off.

      Android has never had the same application execution model as traditional OSes. Both for foreground and background work. This allows it to scale multitasking with the available resources, mostly RAM, without losing app/user data. In other words Android can work on a 512MB RAM device or 8GB device and the only obvious difference would be how many apps are kept in memory. No data will be lost in either case due to apps getting evicted out of RAM. I typically give a 3-hour lecture to my interns on this because they need to know the details but that’s what it boils down to. 😂

    • aluminium@lemmy.worldOPEnglish
      4·
      2 months ago

      Thanks a lot for the detailed explanation. If I understand it correctly, there is no way to really prevent these Apps from “running” in the background, although “running” just means they sit idle in memory 99.9% of time and don’t do anything unless a broadcast event they are subscribed to gets fired and then they are permitted to do small task.

      So I guess the most likely issue is that either something else on the phone is causing this drain or that some App constantly gets restarted (which is expensive) for some reason instead of just staying idle in memory.