I have static library code from which I'm attempting to use NSProcessInfo.performExpiringActivity() to ensure that our app isn't background-terminated in the middle of a relatively short (yet important) periodic background task. However, what's currently tripping me up is how NSProcessInfo.performExpiringActivity()'s block can be invoked more than once:let queue: DispatchQueue = DispatchQueue(label: "com.my-company.ios.foo", qos: .utility)
let timer = DispatchSource.makeTimerSource(queue: queue)
timer.setEventHandler { [weak self] in
guard let self = self, let managedObjectContext = self.managedObjectContext else {
timer.cancel()
return
}
timer.suspend()
ProcessInfo.processInfo.performExpiringActivity(withReason: "Performing activity") { expired in
defer {
timer.resume()
}
guard !expired else {
return
}
managedObjectContext.performAndWait {
...
}
}
}In this case, if the block is called a second time, the timer will be over-resumed and result in a crash. I could add more book-keeping variables to guard against this, but it'll certainly make the code more difficult to maintain and reason about.Is there a more elegant and/or correct way to do this? (Links to sample code or write-ups would be appreciated!)
djs-code2
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The Apple Developer forums haven't received a signifigant update in a long time, and is missing a many features found in most modern forum software. With the success of the Swift Discourse, would moving this broader Apple Developer ecosystem forum to its own Discourse (or similar) be considered?