Re: NSTimer and seg faults

FROM : Hamish Allan
DATE : Wed Mar 12 22:03:19 2008

Hi Gregory,

The method [NSDate date] returns an autoreleased object, which has
been dealloced by the time your NSTimer fires.

I'd recommend reading the documentation on memory management, starting with:

http://developer.apple.com/documentation/Cocoa/Conceptual/MemoryMgmt/MemoryMgmt.html

Best wishes,
Hamish

On Wed, Mar 12, 2008 at 8:56 PM, Gregory Short <<email_removed>> wrote:
>        Howdy all, first-time poster here. I'm pretty new to Objective-C and
>  it's associated run-time environment, so I apologize if this is a
>  total newbie question that has been answered before (I couldn't find
>  anything, but I might not know where to look.)
>        My problem is this: I have an NSTimer which I set up in my NSView's -
>  awakeFromNib method. Also in -awakeFromNib, I set create an NSDate
>  object as part of the NSView. This all works fine. The problem is,
>  when my timer fires, if I try to do anything at all with the NSDate
>  object I created before, the program chokes. Here's the relevant
>  portion of the code (I've stripped out what appears to be irrelevant;
>  if anyone wants to see more, that's fine.)
>
>  BlobView.h:
>
>  @interface BlobView : NSOpenGLView
>  {
>        NSTimer* updateTimer;
>        NSDate* lastUpdate;
>  }
>
>  - (void) updateTimer: (NSTimer *) timer;
>
>  @end
>
>
>
>  BlobView.m:
>
>  @implementation BlobView
>
>  - (void) awakeFromNib {
>        lastUpdate = [NSDate date];
>        NSLog(@"%lf", [lastUpdate timeIntervalSinceNow]); // This works fine
>
>        updateTimer = [NSTimer scheduledTimerWithTimeInterval: 1.0 / 30.0
>                target: self
>                selector: @selector(updateTimer:)
>                userInfo: nil
>                repeats: YES];
>  }
>
>  - (void) updateTimer: (NSTimer *) timer {
>        NSLog(@"%lf", [lastUpdate timeIntervalSinceNow]); // This produces a
>  SIGBUS
>  }
>
>  @end
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