Background
In the past, I've found the next method of killing an app's background processes, given its package name:
public static boolean killApp(final Context context, final String packageName) {
final ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
final List<ActivityManager.RunningAppProcessInfo> pids = am.getRunningAppProcesses();
for (int i = 0; i < pids.size(); i++) {
final ActivityManager.RunningAppProcessInfo info = pids.get(i);
if (info.processName.equals(packageName)) {
android.os.Process.killProcess(info.pid);
if (new File("/system/bin/kill").exists()) {
InputStream inputStream = null;
try {
inputStream = Runtime.getRuntime().exec("kill -9 " + info.pid).getInputStream();
final byte[] buffer = new byte[100];
inputStream.read(buffer);
} catch (final IOException e) {
}
StreamsUtil.closeStream(inputStream);
}
am.killBackgroundProcesses(packageName);
return true;
}
}
am.killBackgroundProcesses(packageName);
return false;
}
The problem
Ever since a specific Android version (5.1), the function to get the list of running processes only returns the current app's processes, so it's quite useless to use it.
What I've found
Most apps on the Play Store indeed fail to show a list of processes, and instead, show just the current app's process or a list of services at most.
It seems that some apps still manage to show background apps processes and even be able to kill them. As an example, I've found AVG's app that's capable of doing so, here .
Before they can do it, they tell the user to enable the usage stats settings for the app, which I remember of using for checking general information of apps launch time.
Another app that succeeded killing background processes, yet without any user confirmation , is "fast task killer". It also shows a toast of all processes being killed. I could be wrong, but it seems that it's always the same number of tasks.
I also think there is a relatively easy way to get the list of processes using the "ps" function, but only if the device is rooted (otherwise it will return just the current app's processes).
There was a temporary solution with a library, found here (published here), but this doesn't seem to work on Android 7.1.2 , and most probably on previous versions.
The question
How do apps get the list of apps that have background processes, and how do they kill them?
Is it possible to do so without using the UsageStatsManager class ?
