在数据库执行大量后台工作时冻结和应用的最佳方法是什么？

I have a background service that does some heavy lifting within a transaction once a day. If the user happens to start the app at this time, I want them to sit tight till it finishes (around 10 secs or so). What's the best way to do this across all activities? Check if the service is running in the "onResume" function of each activity? And how do we know when it's done? Local broadcasts I'm guessing...I have a background service that does some heav