So don't create a new for matter every time.
Create one once outside of the timer.
Formatters are heavy.
Beyond that you might try judicious use of @autorelease{}
Sent from my iPhone
> On Aug 15, 2015, at 5:29 AM, Richard Kennaway <rich...@kennaway.org.uk> wrote:
>
> I've written an iOS app that, according to Instruments, seems to very slowly
> allocate more and more memory over time, although I can see no reason for it.
> After starting it, and letting it settle down, I see in the Allocations tool
> several entries in the "#Persistent" column creeping upwards. Typically, I
> see an item "CFArray (mutable-variable)" incrementing its #Persistent once a
> second, and an item "Malloc 32 Bytes" incrementing by 2 every second. The
> Leaks tool shows nothing. Taking Generation snapshots at intervals of a
> second or two shows the steady accumulation of small allocations, described
> as <non-object>.
>
> I'm using XCode 6.4 and running this in the simulator for iPhone 6 and iOS
> 8.4. I've also tried the iPad2 and iOS 8.4 with similar results, although
> there the item that ticks up and up is "Malloc 64 bytes", at a rate of about
> 1 KB every 5 seconds. The project is compiled with ARC turned on. The high
> water mark of total memory use displayed in XCode increases by a megabyte in
> something over an hour and an overnight run shows no sign of it stopping.
>
> But I cannot see what is causing this. It's a very small app, and if I let
> it run without interacting with it, the only code it executes is the
> following method of the single view controller, invoked by an NSTimer once a
> second to update a display of the time.
>
> - (void)updateTime {
> NSDate *now = [NSDate date];
> double seconds = [now timeIntervalSinceReferenceDate];
> double intseconds = round(seconds);
> now = [NSDate dateWithTimeIntervalSinceReferenceDate:intseconds];
>
> [dateFormatter setDateFormat:
> [NSDateFormatter dateFormatFromTemplate:@"jjmmss" options: 0 locale:
> thelocale]];
> [[self timestring] setText: [dateFormatter stringFromDate: now]];
>
> [dateFormatter setDateFormat:
> [NSDateFormatter dateFormatFromTemplate:@"EEEdMMM" options: 0 locale:
> thelocale]];
> [[self daystring] setText: [dateFormatter stringFromDate: now]];
>
> [dateFormatter setDateFormat:
> [NSDateFormatter dateFormatFromTemplate:@"yyyy" options: 0 locale:
> thelocale]];
> [[self yearstring] setText: [dateFormatter stringFromDate: now]];
> }
>
> timestring, daystring, and yearstring are properties of my ViewController
> class connected to labels in the storyboard:
>
> @property (weak, nonatomic) IBOutlet UILabel *timestring;
> @property (weak, nonatomic) IBOutlet UILabel *daystring;
> @property (weak, nonatomic) IBOutlet UILabel *yearstring;
>
> dateFormatter and thelocale are private instance variables, initialised once
> in viewDidLoad(). I've also tried versions where these are variables local
> to updateTime(), and where "now" is an instance variable, but moving these
> around gives the same results. I've also tried, with equal lack of effect,
> splitting up some of the one-liners into things like:
>
> NSString *thestring = [dateFormatter stringFromDate: now];
> [[self timestring] setText: thestring];
>
> When the app is in the background it does nothing (it invalidates the NSTimer
> and sets the instance variable holding it to NULL), and Allocations reports
> no activity.
>
> What is causing this problem? Instruments says the Responsible Library is
> libdispatch.dylib, and the Responsible Caller is
> _dispatch_continuation_alloc_from_heap. The names suggest that this may be
> nothing to do with the code above. Google turns up a small number of queries
> regarding memory leaks with similar symptoms, but no answers.
>
> --
> Richard Kennaway
>
>
> _______________________________________________
>
> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
>
> 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:
> https://lists.apple.com/mailman/options/cocoa-dev/dangerwillrobinsondanger%40gmail.com
>
> This email sent to dangerwillrobinsondan...@gmail.com
_______________________________________________
Cocoa-dev mailing list (Cocoa-dev@lists.apple.com)
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:
https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com
This email sent to arch...@mail-archive.com
