On Jul 21, 2011, at 6:40 PM, Corbin Dunn wrote: > Log the address of your object. Then, break in gdb and do: > > info gc-roots <address> > > Then see what is rooting it. also, try gc-references in it to see what > references it, but roots are more important.
Thanks, Corbin. I'm trying to understand the output of gc-roots. On 10.6, for the NSDocument subclass (CCMDoc) instance I get this: (gdb) info gc-roots 0x1670a40 Number of roots: 1 Root: 0 Kind: bytes rc: -1847835481 Address: 0x01670a40 On 10.7, I get unpredictable results. Sometimes there is one root, and sometimes there are several. Here is a short output: (gdb) info gc-roots 0x1824f00 Number of roots: 1 Root: 0 Kind: bytes rc: 1 Address: 0x011ee790 Offset: 0x00000014 1 Kind: object rc: 0 Address: 0x014a65d0 Class: CCMDocumentWindow ivar: NSWindow.NSResponder 2 Kind: object rc: 0 Address: 0x01b11e60 Class: CCMWindowCtl ivar: _paletteGroups 3 Kind: object rc: 0 Address: 0x014d7950 Class: NSView Offset: 0x0000002c 4 Kind: object rc: 0 Address: 0x01f28db0 Offset: 0x00000014 Class: __NSArrayM 5 Kind: bytes rc: 0 Address: 0x01f28fa0 6 Kind: object rc: 0 Address: 0x018b9490 Class: CCMPaletteGroup ivar: NSView._subviews 7 Kind: object rc: 0 Address: 0x01f1cdb0 Offset: 0x00000014 Class: __NSArrayM 8 Kind: bytes rc: 0 Address: 0x01f27d30 Offset: 0x0000000c 9 Kind: object rc: 0 Address: 0x014cda10 Class: CCMCollapsingView ivar: NSView._subviews 10 Kind: object rc: 0 Address: 0x014c8cb0 Offset: 0x00000014 Class: __NSArrayM 11 Kind: bytes rc: 0 Address: 0x014c9b10 Offset: 0x00000008 12 Kind: object rc: 0 Address: 0x014c77f0 Class: CCMUnitTextFieldPointsOnly ivar: CCMUnitTextField.NSTextField.NSControl 13 Kind: object rc: 0 Address: 0x014fcb00 Class: NSTextFieldCell ivar: NSActionCell 14 Kind: object rc: 0 Address: 0x014ea670 Offset: 0x0000004c Class: NSKVONotifying_CCMFormatCtl 15 Kind: object rc: 0 Address: 0x01824f00 Offset: 0x00000000 Class: NSKVONotifying_CCMDoc and here is a long one: (gdb) info gc-roots 0x1827500 Number of roots: 5 Root: 0 Kind: bytes rc: 1 Address: 0x0143ec20 Offset: 0x00000014 1 Kind: bytes rc: 0 Address: 0x0143ed60 Offset: 0x00000014 2 Kind: object rc: 0 Address: 0x018df290 Class: CCMTextViewFooter ivar: CCMTextViewSection.CCMTextView.NSTextView.NSText._ivars 3 Kind: object rc: 0 Address: 0x014b4d70 Offset: 0x00000014 Class: NSTextViewIvars 4 Kind: object rc: 0 Address: 0x018e0fc0 Class: CCMLayoutManager Offset: 0x000000d8 5 Kind: object rc: 0 Address: 0x01827500 Offset: 0x00000000 Class: NSKVONotifying_CCMDoc Root: 0 Kind: bytes rc: 1 Address: 0x01443f20 Offset: 0x00000014 1 Kind: bytes rc: 0 Address: 0x01444500 Offset: 0x00000014 2 Kind: object rc: 0 Address: 0x018e1d50 Class: CCMTextViewHeader ivar: CCMTextViewSection.CCMTextView.NSTextView.NSText._ivars 3 Kind: object rc: 0 Address: 0x018f3280 Offset: 0x00000014 Class: NSTextViewIvars 4 Kind: object rc: 0 Address: 0x018e4730 Class: CCMLayoutManager Offset: 0x000000d8 5 Kind: object rc: 0 Address: 0x01827500 Offset: 0x00000000 Class: NSKVONotifying_CCMDoc Root: 0 Kind: bytes rc: 1 Address: 0x011ab020 Offset: 0x00000014 1 Kind: bytes rc: 0 Address: 0x011ac2c0 Offset: 0x00000014 2 Kind: object rc: 0 Address: 0x01879770 Class: CCMTextViewColumn ivar: CCMTextView.NSTextView.NSText._ivars 3 Kind: object rc: 0 Address: 0x01853510 Offset: 0x00000014 Class: NSTextViewIvars 4 Kind: object rc: 0 Address: 0x018d7050 Class: CCMColumnLayoutManager ivar: CCMLayoutManager 5 Kind: object rc: 0 Address: 0x01827500 Offset: 0x00000000 Class: NSKVONotifying_CCMDoc Root: 0 Kind: bytes rc: 1 Address: 0x01817670 Offset: 0x00000014 1 Kind: object rc: 0 Address: 0x0182a9a0 Class: CCMDocumentWindow ivar: NSWindow.NSResponder 2 Kind: object rc: 0 Address: 0x018321b0 Class: CCMWindowCtl ivar: _paletteGroups 3 Kind: object rc: 0 Address: 0x01816fb0 Class: NSView Offset: 0x0000002c 4 Kind: object rc: 0 Address: 0x0183ad60 Offset: 0x00000014 Class: __NSArrayM 5 Kind: bytes rc: 0 Address: 0x018760d0 6 Kind: object rc: 0 Address: 0x01853a00 Class: CCMPaletteGroup ivar: NSView._subviews 7 Kind: object rc: 0 Address: 0x014f6100 Offset: 0x00000014 Class: __NSArrayM 8 Kind: bytes rc: 0 Address: 0x01893110 Offset: 0x0000000c 9 Kind: object rc: 0 Address: 0x014db880 Class: CCMCollapsingView ivar: NSView._subviews 10 Kind: object rc: 0 Address: 0x014b1cd0 Offset: 0x00000014 Class: __NSArrayM 11 Kind: bytes rc: 0 Address: 0x014b23c0 Offset: 0x00000008 12 Kind: object rc: 0 Address: 0x01827330 Class: CCMUnitTextFieldPointsOnly ivar: CCMUnitTextField.NSTextField.NSControl 13 Kind: object rc: 0 Address: 0x014e8520 Class: NSTextFieldCell ivar: NSActionCell 14 Kind: object rc: 0 Address: 0x0182f5d0 Offset: 0x0000004c Class: NSKVONotifying_CCMFormatCtl 15 Kind: object rc: 0 Address: 0x01827500 Offset: 0x00000000 Class: NSKVONotifying_CCMDoc Root: 0 Kind: bytes rc: 1 Address: 0x014888b0 Offset: 0x00000014 1 Kind: object rc: 0 Address: 0x0182a9a0 Class: CCMDocumentWindow ivar: NSWindow.NSResponder 2 Kind: object rc: 0 Address: 0x018321b0 Class: CCMWindowCtl ivar: _paletteGroups 3 Kind: object rc: 0 Address: 0x01816fb0 Class: NSView Offset: 0x0000002c 4 Kind: object rc: 0 Address: 0x0183ad60 Offset: 0x00000014 Class: __NSArrayM 5 Kind: bytes rc: 0 Address: 0x018760d0 6 Kind: object rc: 0 Address: 0x01853a00 Class: CCMPaletteGroup ivar: NSView._subviews 7 Kind: object rc: 0 Address: 0x014f6100 Offset: 0x00000014 Class: __NSArrayM 8 Kind: bytes rc: 0 Address: 0x01893110 Offset: 0x0000000c 9 Kind: object rc: 0 Address: 0x014db880 Class: CCMCollapsingView ivar: NSView._subviews 10 Kind: object rc: 0 Address: 0x014b1cd0 Offset: 0x00000014 Class: __NSArrayM 11 Kind: bytes rc: 0 Address: 0x014b23c0 Offset: 0x00000008 12 Kind: object rc: 0 Address: 0x01827330 Class: CCMUnitTextFieldPointsOnly ivar: CCMUnitTextField.NSTextField.NSControl 13 Kind: object rc: 0 Address: 0x014e8520 Class: NSTextFieldCell ivar: NSActionCell 14 Kind: object rc: 0 Address: 0x0182f5d0 Offset: 0x0000004c Class: NSKVONotifying_CCMFormatCtl 15 Kind: object rc: 0 Address: 0x01827500 Offset: 0x00000000 Class: NSKVONotifying_CCMDoc Looking at the short example, can you tell me what it is saying? My guess is that the output says, "Deep in the window's view hierarchy there is a cell that is bound to CCMFormatCtl which in turn is bound to your CCMDoc instance." So I comment out the line that creates the CCMFormatCtl instance, run the app again, close the window, and I get this: (gdb) info gcc-roots 0x1817360 Number of roots:0 But the document still does not get collected. Its -finalize method does not fire. All words of wisdom are appreciated. I try to use a tech support incident on this, but it came back with a request to file a bug report instead. Ross _______________________________________________ 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
