Background Queue processes Terminates app when minimised - swift

Question

I have 3 Background Queue tasks running on app launch. They take approximately 25sec to complete. There is no memory issues, nor an issue with the tasks themselves, the tasks simply go through a database for filtering/reading data purposes (SQLite).
If I minimise the app whilst the tasks are running, the app is killed within 3sec, as any time I go back to the app after 3 sec the app starts again. I get the "Message from debugger: Terminated due to signal 9" as soon as I minimise the app. I use Swift and iOS14, is there a way to complete 30sec or less background SQLite DB tasks with the app not released from memory? Or just pause/kill the tasks to prevent killing the app?
I run my tasks using the DispatchQueue Extension:
extension DispatchQueue {
static func background(delay: Double = 0.0, background: (()->Void)? = nil, completion: (() -> Void)? = nil) {
DispatchQueue.global(qos: .background).async {
background?()
if let completion = completion {
DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: {
completion()
})
}
}
}
static func backgroundFast(delay: Double = 0.0, background: (()->Void)? = nil, completion: (() -> Void)? = nil) {
DispatchQueue.global(qos: .default).async {
background?()
if let completion = completion {
DispatchQueue.main.asyncAfter(deadline: .now() + delay, execute: {
completion()
})
}
}
}
}

Answer 1

If you only need 25 seconds for your backgound tasks to complete you should be able to call the beginBackgroundTask(withName:expirationHandler:) method in response to your app delegate's applicationDidEnterBackground(_:) method being called.
That will give you up to 3 minutes of background time.
See this article for Apple for more information.
https://developer.apple.com/documentation/uikit/app_and_environment/scenes/preparing_your_ui_to_run_in_the_background/extending_your_app_s_background_execution_time
One thing to be aware of (Quoting Apple's docs)
Warning
If you are using scenes (see Scenes), UIKit will not call this
method. Use sceneDidEnterBackground(_:) instead to perform any final
tasks. UIKit posts a didEnterBackgroundNotification regardless of
whether your app uses scenes.