applicationState is UIApplicationStateInactive in application:didReceiveRemoteNotification:fetchCompletionHandler:

Question

When a push notification arrives, it plays audio in the background with application:didReceiveRemoteNotification:fetchCompletionHandler:.

To get it started, I press the home button, then lock screen button, then the screen is off, then send a push notification. This works when app state is UIApplicationStateBackground and I see the state by logging it to a file. Sometimes however when the app is backgrounded it mysteriously goes into the foreground right before application:didReceiveRemoteNotification:fetchCompletionHandler: and the app state is UIApplicationStateInactive in application:didReceiveRemoteNotification:fetchCompletionHandler:. Here's the log:

AppDelegate applicationDidEnterBackground: called
AppDelegate applicationWillEnterForeground: called
AppDelegate application:didReceiveRemoteNotification:fetchCompletionHandler: called. currentThread 0x174261900 isMainThread 1
AppDelegate application:didReceiveRemoteNotification:fetchCompletionHandler: applicationState == UIApplicationStateInactive

On some phones in application:didReceiveRemoteNotification:fetchCompletionHandler: it consistently shows UIApplicationStateBackground and on others it is UIApplicationStateInactive. Any idea why this happens?

Answer 1

In modern operating systems, background processes are either "suspended" so they can be pulled up quicker (state is UIApplicationStateBackground) or their memory is deallocated to give memory to a more frontal process. In this case, it becomes your UIApplicationStateInactive. This happens when your device has an intense process up and needs the RAM for it.