gistfile1.txt

    UIBackgroundTaskIdentifier bgTask;


 if ([UIApplication sharedApplication].applicationState == UIApplicationStateBackground) {


    bgTask = [[UIApplication sharedApplication]
              beginBackgroundTaskWithExpirationHandler:
              ^{
                  [[UIApplication sharedApplication] endBackgroundTask:bgTask];
            }];
    
    [self disconnect]
                  
    if (bgTask != UIBackgroundTaskInvalid) {
        [[UIApplication sharedApplication] endBackgroundTask:bgTask];
        bgTask = UIBackgroundTaskInvalid;
    }

}