How do you prevent multiple instances of the same run forever scripts from running?

I have a background/loop script. If I trigger it once and issue the "Stop All Running Commands" command from the SF menu or keyboard command one error message is displayed via notifications.

I noticed that if I trigger the background script multiple times - let's say three times for example - and I stop all running commands then I get three error notifications which leads me to believe that there are multiple instances of the background script running.

Is this right and if so is there a way to prevent this? I've tried using a globalState at the top of the script to prevent multiple instances running like this:

// Prevent multiple instances of this background process from running
// If this the first time the script has been launched then globalState.backgroundScriptRunning is undefined
 
if (globalState.backgroundScriptRunning == true) { throw 0 };
// Now set globalState.backgroundScriptRunning to true
globalState.backgroundScriptRunning = true

This does work but if I stop all running commands then globalState.backgroundScriptRunning will be set to true and will prevent the script from running again.

Is there another way to do this?

//CS//