[FoRK] Memory Management in iPhone OS4
michael at i-magery.com
Sat Apr 10 16:23:54 PDT 2010
I know the vocal majority here is sick of the subject and the quotes below
are from a very anti-apple piece, but there were some bits here that I
haven't read anywhere else and thought interesting.
This article purports that Apple "hobbled" themselves out of the gate and
are still trying to recover from some of the bad decisions they made early
on, not choosing to "correct their course" with the iPad. The windows
comments on page 2 strike me as a bit silly, but the Apple iPhone memory
management stuff is all (interesting) news to me.
>From Page 1 of the article:
"Specifically, Apple's new operating system will permit applications to
launch one of seven low-resource, pre-approved APIs when you switch out of
them to head to another application. The most important of these APIs are
location-based services, audio streaming, and Voice over Internet Protocol
capabilities. This means that you can keep receiving directions from your
TomTom GPS application after you close the app, and it means you'll be able
to close Skype but keep talking using the VOIP functionality. Using the
audio API, iPhone and iPad users will finally be able to listen to Pandora
Internet radio while running another application.
For some users, this will be just as good as genuine multitasking, which
allows multiple programs to run simultaneously in their entirety. You might
not be able to keep applications open, the theory goes, but at least you can
keep approximations of them running with Apple's APIs while you work
The problem is that quite a few applications will not be able to remain
functional after they're closed in the new iPhone OS because Apple's list of
pre-approved APIs is necessarily small. In the event that you try to
multitask with applications that don't work with those limited APIs, the
illusion of having the "best" in-class multitasking capability crumbles
>From Page 2 of the article:
"From day one, when Apple released the iPhone software development kit to
developers, the company told developers that they were free to make use of
all the available random access memory (RAM) on the device. There wasn't
much of it - even current versions of the iPhone only have 256 MB - but
developers designed their applications with this freedom in mind.
That made developers' lives easier, but it also made a true multitasking
solution impossible from the get-go. If every application thinks it can use
all of the iPhone or iPad's available memory, only one thing will happen
when several applications are independently running full-speed at the same
time: the device, which incidentally lacks the capacity to properly handle
memory strain, will simply crash. Assuming the battery doesn't die first
from the information overload, that is.
That was a mistake that Palm was careful not to repeat when it released its
Pre smartphone last summer. Pre uses a different development model from the
iPhone, and all of the phone's applications use far less RAM than comparable
programs on the iPhone. That makes it feasible for Palm's operating system
to keep multiple programs open side-by-side, without killing the battery and
without causing dreaded "out of memory" errors.
But Apple's so-called "next-generation" iPhone OS is actually outmatched in
the smartphone market not just by Palm's operating system, but also by
Google's increasingly popular Android. What's more, in the tablet arena,
competitors to the iPad are (and have been for years) light-years ahead of
Apple's new multitasking solution. The upcoming HP Slate tablet, for
example, will run the Windows 7 operating system - which, as anyone who
uses a desktop computer knows, enables true multitasking, with programs
running independently of one another with no compromises.
In some ways, though the company's rhetoric is misleading, it's hard to
fault Apple here because they're still trying to work around a mistake they
made years ago, when they created the foundation for the original iPhone's
app ecosystem. But the company's decision to continue using the iPhone's
hobbled operating system on the iPad is more difficult to excuse. It's left
the company in an embarrassing scramble to make their new product look like
a genuine multitasking-capable tablet, since it can't behave like one.
"We shipped the iPad on Saturday," Jobs declared yesterday. "Then, on
Sunday, we rested."
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