in recent iOS, yes On 05-May-2011, at 10:44 PM, Bing Li wrote:
> Dear Fritz and all, > > I am reading one book, Daniel H Steinberg, Cocoa Programming, A Quick-Start > Guide for Developers, 2010. Chapter 26 introduces Dispatch Queues. It > mentions, "If you're writing an iPhone app or a desktop app that targets > Leopard or earlier, you're out of luck." > > Is GCD available when implementing an application on iPad/iPhone? > > Thanks so much! > Bing > > On Mon, Apr 18, 2011 at 2:28 AM, Fritz Anderson > <[email protected]>wrote: > >> On 17 Apr 2011, at 12:04 PM, Bing Li wrote: >> >>> I am programming on iPad. I notice that background applications are not >>> allowed for power issues on iPad. I am not sure how to define the concept >> of >>> background applications? In my system, I need to have multiple threads >> run >>> when users interact with my system. The work done by the threads is the >>> so-called background applications? If so, threading is not allowed? If >> not, >>> what do background application mean exactly? >> >> On iOS, an application is said to be in the background once the user has >> tapped the Home button and returned to the home display (or has >> double-tapped the Home button to expose the recent-app display and selected >> another app). >> >> This usually means that the application is suspended, but preserved in >> memory so it can resume when it comes back to the foreground. There are >> exceptions, if it requests one: It can manage an audio stream or a VoIP >> conversation; it can have the system monitor a VoIP control port or location >> events; or it can simply ask for 10 minutes to execute while it is not >> visible. In any case, if the system needs memory or processor resources for >> the visible application, a background application may be terminated without >> notice. >> >> iOS user applications may not fork/exec additional BSD processes. >> >> You seem to be talking about concurrency, in which a single application >> uses threads to execute more than one independent task at the same time. iOS >> supports threading, and offers several ways to do it: pthreads, NSOperation, >> NSThread, and Grand Central Dispatch. Unless you have existing code that >> uses another technology, Grand Central Dispatch is the recommended method. >> >> A mailing list isn't the place to go into depth. See the Concurrency >> Programming Guide for an overview and pointers to details. < >> http://developer.apple.com/library/ios/#documentation/General/Conceptual/ConcurrencyProgrammingGuide/Introduction/Introduction.html >>> >> >> — F >> >> > _______________________________________________ > > Cocoa-dev mailing list ([email protected]) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/cocoa-dev/rols%40rols.org > > This email sent to [email protected] _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
