Are the apps in the tray actaully running?

Discussion in 'iPhone' started by VydorScope, Oct 19, 2011.

  1. VydorScope macrumors regular

    VydorScope

    Joined:
    Oct 12, 2011
    #1
    If I double press the home button I see a long list of apps down there. Are all of them actually running or are they just a list of recently used things?
     
  2. deeddawg macrumors 604

    Joined:
    Jun 14, 2010
    Location:
    US
    #2
    Generally not, those are recently run / saved-states.
     
  3. VydorScope thread starter macrumors regular

    VydorScope

    Joined:
    Oct 12, 2011
    #3
    What does removing them do? Just remove the short cut till next time I run the app, or will it kill it if an app is a bad state?
     
  4. aneftp macrumors 68040

    Joined:
    Jul 28, 2007
    #4
    Some apps are approved to run in the background and waste battery like tom tom navigation or pandora
     
  5. oshia86 macrumors regular

    Joined:
    Sep 15, 2011
    #5
    Exiting them can free up memory, so they do use some resources.
     
  6. CSMchris376 macrumors regular

    Joined:
    Mar 13, 2010
    Location:
    Illinois
    #6
    It will actually do both. If an app is acting up, removing it from there will force close it like you used to be able to do by holding down the Home button. However, for the most part, it the app does not do something in the background, like the other poster mentioned, it is just sitting there and is a shortcut/quick launch sort of thing. It is the recently used list.
     
  7. jclardy macrumors 68040

    jclardy

    Joined:
    Oct 6, 2008
    #7
    Removing it from there is basically like force closing an app on a mac. The apps terminate methods are not called (They should have already saved what they needed to when the app went into the background.)

    The apps in the tray are "in memory" waiting to be reopened. Most apps only use a small amount of RAM while running. iOS will automatically kill apps from the tray (in order of last used) if it needs more memory for the foreground app.

    Games like infinity blade or Real Racing tell you to restart your phone so that the app gets as large a block of free RAM that it can get. If you have a lot of apps in "saved state" the large app will take longer to open as the system goes through and terminates and frees the memory from the closed apps.

    So in summary, you don't NEED to remove apps from the tray as the system will free things as they are needed, but doing so yourself will free up resources and probably increase app launching speed (But that will be negated by the time you spent killing apps in the first place.)
     
  8. elistan macrumors 6502a

    Joined:
    Jun 30, 2007
    Location:
    Denver/Boulder, CO
    #8
    Depends on the app. Apple has publised a set of various multitasking APIs that developers can use and if the app makes use of them then yes, the app is "running" to the extent that the API allows. So Angry Birds? Probably not using any CPU resources at all. But Pandora? Yeah, it uses the music playing multitasking API to continue. (I assume, I don't actually use it. :) )MotionX GPS? Same deal, exept via the the location services multitasking API.

    You can read about the multitasking abilities of iOS 4 and 5 here:
    http://developer.apple.com/library/...cationsFlow/ManagingYourApplicationsFlow.html
     
  9. VydorScope thread starter macrumors regular

    VydorScope

    Joined:
    Oct 12, 2011

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