finding memory leaks

• Torsten Curdt finding memory leaks Feb 11 2008, 15:25
  ...surely a FAQ but I am a bit struggling with it over this code
  
    http://nopaste.ch/1685f5d17a92cfd.html
  
  For this snippet there is nothing that should live on after the
  blocks has finished. So no "retain" and things should be quite
  straight forward. With the NSAutoreleasePool I just find it hard to
  find out what needs to the "autorelease"'d and what not. ("alloc",
  "new" etc are already covered - I know) But somehow I am still
  failing according to "leaks".
  
  Call stack: [thread 1dad]: | 0x1 | start | _start | main |
  NSApplicationMain | -[NSApplication run] | -[NSApplication
  sendEvent:] | -[NSWindow sendEvent:] | -[NSTextView keyDown:] | -
  [NSView interpretKeyEvents:] | -[NSTSMInputContext
  interpretKeyEvents:] | -[NSKeyBindingManager
  (NSKeyBindingManager_MultiClients) flushTextForClient:] | -
  [NSTextView insertText:] | -[NSTextView(NSSharing) didChangeText] | -
  [NSNotificationCenter postNotificationName:object:userInfo:] |
  _CFXNotificationPostNotification | __CFXNotificationPost |
  _nsnote_callback | -[NSTextField textDidChange:] | -
  [NSNotificationCenter postNotificationName:object:userInfo:] |
  _CFXNotificationPostNotification | __CFXNotificationPost |
  _nsnote_callback | -[MyDocument controlTextDidChange:] |
  CFArrayAppendValue | _CFArrayReplaceValues | malloc_zone_malloc
  Leak: 0x003c9780  size=32    string ' '
  
  Call stack: [thread 1]: | 0x1 | start | _start | main |
  NSApplicationMain | -[NSApplication run] | -[NSApplication
  sendEvent:] | -[NSWindow sendEvent:] | -[NSTextView keyDown:] | -
  [NSView interpretKeyEvents:] | -[NSTSMInputContext
  interpretKeyEvents:] | -[NSKeyBindingManager
  (NSKeyBindingManager_MultiClients) flushTextForClient:] | -
  [NSTextView insertText:] | -[NSTextView(NSSharing) didChangeText] | -
  [NSNotificationCenter postNotificationName:object:userInfo:] |
  _CFXNotificationPostNotification | __CFXNotificationPost |
  _nsnote_callback | -[NSTextField textDidChange:] | -
  [NSNotificationCenter postNotificationName:object:userInfo:] |
  _CFXNotificationPostNotification | __CFXNotificationPost |
  _nsnote_callback | -[MyDocument controlTextDidChange:] | -
  [NSPlaceholderMutableArray init] | -[NSPlaceholderMutableArray
  initWithCapacity:] | __CFArrayInit | _CFRuntimeCreateInstance |
  malloc_zone_malloc
  Leak: 0x003a6760  size=16    string '@/0'
  
  Call stack: [thread 1]: | 0x1 | start | _start | main |
  NSApplicationMain | -[NSApplication run] | -[NSApplication
  sendEvent:] | -[NSWindow sendEvent:] | -[NSTextView keyDown:] | -
  [NSView interpretKeyEvents:] | -[NSTSMInputContext
  interpretKeyEvents:] | -[NSKeyBindingManager
  (NSKeyBindingManager_MultiClients) flushTextForClient:] | -
  [NSTextView insertText:] | -[NSTextView(NSSharing) didChangeText] | -
  [NSNotificationCenter postNotificationName:object:userInfo:] |
  _CFXNotificationPostNotification | __CFXNotificationPost |
  _nsnote_callback | -[NSTextField textDidChange:] | -
  [NSNotificationCenter postNotificationName:object:userInfo:] |
  _CFXNotificationPostNotification | __CFXNotificationPost |
  _nsnote_callback | -[MyDocument controlTextDidChange:] | -
  [NSPlaceholderMutableArray init] | -[NSPlaceholderMutableArray
  initWithCapacity:] | __CFArrayInit | _CFRuntimeCreateInstance |
  malloc_zone_malloc
  Leak: 0x003a5e50  size=16    instance of 'ABSearchElementConjunction'
  0xa47d2f20 0x00000001 0x003c9140 0x00000000  /}.....@.<.....
  
  I need some help here to interpret this output. I have absolutely no
  clue where the leaking strings are coming from. First though
  "stringByTrimmingCharactersInSet" (line 14) but that does not like to
  be autorelease'd. And for the ABSearchElementConjunction that looks
  like searchElementForConjunction:children (line 47) needs an
  autorelease. But when I do add it - the app crashes.
  
  Any help appreciated.
  
  cheers
  --
  Torsten
• Brian Christensen Re: finding memory leaks Feb 11 2008, 15:45
  On Feb 11, 2008, at 09:25, Torsten Curdt wrote:
  
  

  > For this snippet there is nothing that should live on after the
  > blocks has finished. So no "retain" and things should be quite
  > straight forward. With the NSAutoreleasePool I just find it hard to
  > find out what needs to the "autorelease"'d and what not. ("alloc",
  > "new" etc are already covered - I know) But somehow I am still
  > failing according to "leaks".
  

  
  It looks like you're leaking leaking your "queries" NSMutableArray.
  The autorelease pool you established is only responsible for cleaning
  up autoreleased objects, so you need to add in a "[queries release]"
  statement somewhere (or use "queries = [NSMutableArray array]" instead).
  
  You also shouldn't be autoreleasing the result of the
  "searchElementForProperty" messages. This method is (by convention)
  already returning an autoreleased object.
  
  /brian
• Torsten Curdt Re: finding memory leaks Feb 12 2008, 20:23
  On 11.02.2008, at 15:45, Brian Christensen wrote:
  
  

  > On Feb 11, 2008, at 09:25, Torsten Curdt wrote:
  >
  >> For this snippet there is nothing that should live on after the
  >> blocks has finished. So no "retain" and things should be quite
  >> straight forward. With the NSAutoreleasePool I just find it hard
  >> to find out what needs to the "autorelease"'d and what not.
  >> ("alloc", "new" etc are already covered - I know) But somehow I am
  >> still failing according to "leaks".
  >
  > It looks like you're leaking leaking your "queries" NSMutableArray.
  > The autorelease pool you established is only responsible for
  > cleaning up autoreleased objects, so you need to add in a "[queries
  > release]" statement somewhere (or use "queries = [NSMutableArray
  > array]" instead).
  >
  > You also shouldn't be autoreleasing the result of the
  > "searchElementForProperty" messages. This method is (by convention)
  > already returning an autoreleased object.
  

  
  Thanks, Brian! That fixed it. I think I need to do a bit more
  homework in this area.
  
  cheers
  --
  Torsten