Garbage Collection Crash using NSImage
Garbage Collection Crash using NSImage
- Subject: Garbage Collection Crash using NSImage
- From: Kristof Van Landschoot <email@hidden>
- Date: Mon, 1 Jun 2009 15:59:21 -0700
This piece of code was split off from a project I am working on. It
consistently reproduces a garbage collection error on my Mac OS 10.5.7 and
sometimes crashes. I have been looking at it for too long so my question is:
does anybody else see why this would give errors when garbage collection is
on?
- (void) doCrash: (id) sender
{
NSArray *lURLArray = [ NSArray arrayWithObjects:
@"http://userserve-ak.last.fm/serve/300x300/23621007.jpg";,
@"http://userserve-ak.last.fm/serve/300x300/26675609.png";,
@"http://userserve-ak.last.fm/serve/300x300/26675609.png";,
nil ];
NSString *lImageURL = nil;
for (lImageURL in lURLArray)
{
NSImage *lImage = [[NSImage alloc] initWithContentsOfURL:
[NSURL URLWithString: lImageURL]];
NSSize targetSize = NSMakeSize(80,80);
NSImage *newImage = [[NSImage alloc] initWithSize:targetSize];
[newImage lockFocus];
NSRect thumbnailRect = NSMakeRect(0,0,80,80);
NSRect sourceRect = NSMakeRect(0,0,[lImage size].width,[lImage
size].height);
[lImage drawInRect: thumbnailRect
fromRect: sourceRect
operation: NSCompositeSourceOver
fraction: 1.0];
[newImage unlockFocus];
}
}
When playing around with the URLs in the lURLArray I get different behavior:
sometimes crashes, sometimes the error message.
The garbage collection error message is triggered when the garbage collector
is freeing one of the images and goes like this:
reference count underflow for <address>, break on
auto_refcount_underflow_error to debug.
Stack Trace:
#0 auto_refcount_underflow_error ()
#1 Auto::Zone::dec_refcount_small_medium ()
#2 Auto::Zone::block_decrement_refcount ()
#3 CFRelease ()
#4 -[NSBitmapImageRep _freeData] ()
#5 -[NSBitmapImageRep _freeImage] ()
#6 -[NSBitmapImageRep finalize] ()
#7 finalizeOneObject ()
#8 foreach_block_do ()
#9 batchFinalize ()
#10 batchFinalizeOnMainThread ()
#11 objc_collect_if_needed ()
#12 NSPopAutoreleasePool ()
Any help is much appreciated, thanks, Kristof
[ see also
http://stackoverflow.com/questions/937105/garbage-collection-crash-using-nsimagefor
the same question ]
Best Regards,
Kristof
_______________________________________________
Cocoa-dev mailing list (email@hidden)
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:
This email sent to email@hidden