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 | change source]

Fast app switching[change | change 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 | change 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 | change 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 | change source]

References[change | change source]

  1. "iOS 4 iPhone Update RELEASED: A Guide To iOS 4". The Huffington Post. June 21, 2010. Retrieved April 13, 2013.
  2. Albanesius, Chloe (June 21, 2010). "Apple iPhone iOS 4 Software Update Expected Monday". PC Mag.,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. Retrieved April 14, 2013.
  4. Ray, Bill (November 22, 2010). "iOS 4.2 multi-tasking comes to the iPad". The Register. Retrieved April 14, 2013.
  6. Shimpi, Anand (June 22, 2010). "Apple's iOS 4 Explored". AnandTech. 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. Retrieved April 14, 2013.
  9. Snell, Jason (April 8, 2010). "Inside iPhone 4.0's multitasking". MacWorld. Retrieved April 14, 2013.
  10. "Apple iPhone 4". CNet. June 23, 2010. Retrieved April 14, 2013.
  11. Hollington, Jesse (June 21, 2010). "Instant Expert: Secrets & Features of iOS 4". iLounge. Retrieved April 14, 2013.
  12. Newman, Jared (June 22, 2010). "Multitasking With iOS 4 is Horrible: Apple Blew It". PCWorld. Retrieved April 14, 2013.
  13. Diaz, Jesus (April 8, 2010). "How Multitasking Works in the New iPhone OS 4.0". Gizmodo. Retrieved April 14, 2013.
  14. Speirs, Fraser (January 4, 2012). "How iOS multitasking really works". MacWorld. Retrieved April 14, 2013.