Possible? Android Permission Request Concurrency Issue-CodePudding

Is there a possibility that the below code could fail due to the user denying the SCHEDULE_EXACT_ALARM permission after the permissions check and before the alarm is scheduled?

Note: I have never experienced this issue, this is purely an academic excersize.

public class MyService extends Service {

    private void scheduleExactAlarm(Calendar alarmCalendar) {

        if(getApplicationContext().checkSelfPermission(Manifest.permission.SCHEDULE_EXACT_ALARM) != PackageManager.PERMISSION_GRANTED) {
            // handle permission not granted
            return;
        }

        // can the user deny the permission here?

        AlarmManager.AlarmClockInfo alarmInfo = // create alarmInfo with desired information
        PendingIntent alarmOperation = // create alarmOperation with desired intent    
        AlarmManager alarmManager = getSystemService(AlarmManager.class);    
        alarmManager.setAlarmClock(alarmInfo, alarmOperation);
    }
    
    // the rest of the service implementation...

}

CodePudding user response：

Theoretically? Sure, if the OS decided to task switch taking the processor away from the app, and the user denied permission before it task switched back. Practically? No, task switches happen many times a second, there's no way it wouldn't get a time slice before a user would do that.

CodePudding user response：

No, it is not possible. Android will terminate your process if Android revokes a permission for any reason (user revoked it in Settings, auto-revocation due to lack of app use on Android 12 , etc.).

That being said, Ian Lake's comment is also valid: checkSelfPermission(Manifest.permission.SCHEDULE_EXACT_ALARM) should never return PERMISSION_GRANTED. While your concern is valid for dangerous permissions, based on current 13 DP1 behavior, SCHEDULE_EXACT_ALARM is not categorized as dangerous and is not part of the runtime permission system.