Instance Property


A value of type NSQualityOfService, which controls how aggressively the system schedules the activity.


@property NSQualityOfService qualityOfService;


Options include:

  • NSQualityOfServiceUserInteractive

  • NSQualityOfServiceUserInitiated

  • NSQualityOfServiceUtility

  • NSQualityOfServiceBackground

The default value is NSQualityOfServiceBackground. If you upgrade the quality of service above this level, the system schedules the activity more aggressively. The default value is the recommended value for most activities. See Configure Scheduler Properties. For information about quality of service, see Prioritize Work at the Task Level in Energy Efficiency Guide for Mac Apps.

See Also

Background Scheduler Attributes


A unique reverse DNS notation string, such as com.example.MyApp.updatecheck, that identifies the activity.


A Boolean value indicating whether the activity should be rescheduled after it completes.


An integer providing a suggested interval between scheduling and invoking the activity.


A Boolean value indicating whether your app should stop performing background activity and resume at a more optimal time.


A value of type NSTimeInterval, which specifies a range of time during which the background activity may occur.