Android global mutex?

Question

I have a series of Android apps, and I need to coordinate their execution. On any given device, there can be any one of those apps installed, or any two of them installed, or any three of them, or any four, and so on. All of those apps can do one specific thing, and they all will try to do that thing from time to time. Now here's the problem: at any instant, at most one of those apps should be allowed to do that thing. If any one app is doing that thing, none of the other apps should be doing it; they should either wait for their turn, or simply pass. In other words, I need a global mutex or critical section mechanism on Android. In addition, I want to avoid NDK, if possible. What should I do?

Answer 1

You might have to give a bit more detail to get a more specific answer. But from what I understand it sounds like you could use BroadcastReceiver in each application that listens for an action to get broadcast and takes it as sign that it needs to either wait, or cancel it's action. Then inside each application whenever you are going to start your action you broadcast an intent with the action string something like `com.your.packagename.ACTION_STARTING_THE_THING. All of the other apps that are installed (if any) will receive this intent and can act upon it accordingly.