Multitasking (iOS)

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Multitasking is a feature available on iOS that allows multiple applications to run and perform tasks at the same time. It is available in iOS 4 or later.

Multitasking was first released in June 2010 with the release of iOS 4.0.[1][2] Only iPhone 4, iPhone 3GS, and iPod Touch 3rd generation were able to use multitasking.[3] The iPad did not get multitasking until iOS 4.2 was released in November 2010.[4] Multitasking is currently supported on iPhone 3GS or newer, iPod Touch 3rd generation or newer, and all iPad models.[5]

Features[change | edit source]

Fast app switching[change | edit source]

Fast app switching lets apps to pause and resume themselves quickly and easily change to other apps.[6]An app that is on the screen is "running". An app that is not on screen but is still in memory is "suspended".[7] All apps that are built with iOS 4 SDK support fast app switching if running on iOS 4 and a compatible device.[8] Users can use fast app switching by opening the multitasking bar. The multitasking bar can be displayed by double-tapping the home button.[7][3]

Task completion[change | edit source]

Task completion lets apps continue a certain task after the app has been suspended.[9][10] Apps can ask for up to ten minutes to complete a task in the background in iOS 4.0 or later.[11]

Running in the background[change | edit source]

Apps can run in the background by using background APIs. The following are available in iOS 4.0 or later:[12][13]

  • Audio—plays audio
  • Location—uses location services
  • VOIP—makes VOIP calls

The following two APIs were added in iOS 5.0:[14]

  • Newsstand—downloads content for Newsstand
  • External accessory—interacts with an external accessory

Related pages[change | edit source]

References[change | edit source]

  1. "iOS 4 iPhone Update RELEASED: A Guide To iOS 4". The Huffington Post. June 21, 2010. http://www.huffingtonpost.com/2010/06/21/ios-4-iphone-update-relea_n_619343.html. Retrieved April 13, 2013.
  2. Albanesius, Chloe (June 21, 2010). "Apple iPhone iOS 4 Software Update Expected Monday". PC Mag. http://www.pcmag.com/article2/0,2817,2365351,00.asp. Retrieved April 14, 2013.
  3. 3.0 3.1 Cheng, Jacqui (June 21, 2010). "Ars reviews iOS 4: what’s new, notable, and what needs work". Ars Technica. http://arstechnica.com/apple/2010/06/ars-reviews-ios-4-whats-new-and-notable/. Retrieved April 14, 2013.
  4. Ray, Bill (November 22, 2010). "iOS 4.2 multi-tasking comes to the iPad". The Register. http://www.wired.com/gadgetlab/2010/09/ipad-ios42/. Retrieved April 14, 2013.
  5. http://support.apple.com/kb/ht4211
  6. Shimpi, Anand (June 22, 2010). "Apple's iOS 4 Explored". AnandTech. http://www.anandtech.com/show/3779/apples-ios-4-explored/2. Retrieved April 14, 2013.
  7. 7.0 7.1 Perenson, Melissa (June 8, 2010). "Multitasking on Apple's iPhone 4: How Does It Work?". PCWorld. http://www.pcworld.com/article/198296/iphone_4_multitasking.html. Retrieved April 14, 2013.
  8. https://developer.apple.com/library/ios/#releasenotes/General/WhatsNewIniOS/Articles/iPhoneOS4.html#//apple_ref/doc/uid/TP40009559-SW1
  9. Snell, Jason (April 8, 2010). "Inside iPhone 4.0's multitasking". MacWorld. http://www.macworld.com/article/1150496/multitasking_iphone.html. Retrieved April 14, 2013.
  10. "Apple iPhone 4". CNet. June 23, 2010. http://reviews.cnet.com/iphone-4-review. Retrieved April 14, 2013.
  11. Hollington, Jesse (June 21, 2010). "Instant Expert: Secrets & Features of iOS 4". iLounge. http://www.ilounge.com/index.php/articles/comments/instant-expert-secrets-features-of-ios-4/. Retrieved April 14, 2013.
  12. Newman, Jared (June 22, 2010). "Multitasking With iOS 4 is Horrible: Apple Blew It". PCWorld. http://www.pcworld.com/article/199528/Multitasking_With_iOS_4_is_Horrible_Apple_Blew_It.html. Retrieved April 14, 2013.
  13. Diaz, Jesus (April 8, 2010). "How Multitasking Works in the New iPhone OS 4.0". Gizmodo. http://gizmodo.com/5512656/how-multitasking-works-in-the-new-iphone-os-40. Retrieved April 14, 2013.
  14. Speirs, Fraser (January 4, 2012). "How iOS multitasking really works". MacWorld. http://www.macworld.com/article/1164616/how_ios_multitasking_really_works.html. Retrieved April 14, 2013.