NSXMLParser *rssParser is causing a memory leak.

Marco · 10-09-2008, 01:46 AM

I have been trying to figure out why the NSXMLParser *rssParser is causing a memory leak. I have commented out all of my code and I believe this line is causing it. I am trying to parse a webservice using NSXMLParser, maybe I need to use something else?

Code:

- (void)parseXMLFileAtURL:(NSString *)URL
{	
    NSMutableArray * messageCountArray = [[NSMutableArray alloc] init];
    NSURL *xmlURL = [NSURL URLWithString:URL];
    NSXMLParser *rssParser = [[NSXMLParser alloc] initWithContentsOfURL:xmlURL]; // causes leak, I believe
	
    [messageCountArray release];
    [xmlURL release];
    [rssParser release];
}

I have also used Instruments with Apple's SeismicXML example and it also shows a leak.

Any ideas and help are appreciated.

bikr · 10-09-2008, 11:17 AM

The only leak I see happening in seismic is when you click a row and safari is launched. My thought, without even looking at the code, is that the NSString they build for the url of the click isn't released because the app terminates to launch safari.. Just a hunch..

Marco · 10-09-2008, 01:09 PM

Thanks for your help.

I just cannot figure out how why this line causes a leak, even when I release right after?

NSXMLParser *rssParser = [[NSXMLParser alloc] initWithContentsOfURL:xmlURL];

Marco

lapse · 10-09-2008, 01:16 PM

Maybe NSXMLParser is using pool'd memory. Try wrapping an NSAutoreleasePool around your NSXMLParser.

Marco · 10-09-2008, 01:47 PM

Yep I tried using the NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; and it still leaks memory there, weird.

lapse · 10-09-2008, 02:28 PM

Why are you releasing xmlURL? It's not created by you.

Marco · 10-09-2008, 06:48 PM

I was trying to release everything to see if I could get it to stop leaking...

So I should not be releasing the xmlURL?

lapse · 10-09-2008, 06:54 PM

No because it is not alloc'd by you.

ichi · 01-06-2009, 08:00 AM

I had this problem and it was doing my head in...

If I did this it like this (using NSData to load the file)

Code:

NSString *path = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"index.xml"];
NSData *xml = [NSData dataWithContentsOfFile:path];
	
NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithData:xml];

Then it didn't leak, but if I did this (loading it from an URL)...

Code:

NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithContentsOfURL:url];

It leaked (small, but still annoying).
I found a post that said if you put this before you init the xmlParser, then it stops it leaking and it worked for me...

Code:

[[NSURLCache sharedURLCache] setMemoryCapacity:0];
[[NSURLCache sharedURLCache] setDiskCapacity:0];

I hope that helps someone else, as I've spent hours trying to figure that out...

RomainL · 07-28-2009, 01:55 PM

Quote:

Originally Posted by ichi

I had this problem and it was doing my head in...

If I did this it like this (using NSData to load the file)

Code:

NSString *path = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"index.xml"];
NSData *xml = [NSData dataWithContentsOfFile:path];
	
NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithData:xml];

Then it didn't leak, but if I did this (loading it from an URL)...

Code:

NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithContentsOfURL:url];

It leaked (small, but still annoying).
I found a post that said if you put this before you init the xmlParser, then it stops it leaking and it worked for me...

Code:

[[NSURLCache sharedURLCache] setMemoryCapacity:0];
[[NSURLCache sharedURLCache] setDiskCapacity:0];

I hope that helps someone else, as I've spent hours trying to figure that out...

Unfortunately, my NSXMLParser is leaking, even when putting those 2 lines of cache configuration. I was using initWithData anyway, and calling initWithContentsOfURL didn't change anything. Don't know what to do then...

sani212 · 03-04-2010, 04:05 AM

From what I understand from this page, this is an Apple bug. Hopefully it'll be resolved soon.