On Jun 17, 2011, at 15:51, Greg Parker wrote: > On Jun 17, 2011, at 3:48 PM, Laurent Daudelin wrote: > >> On Jun 17, 2011, at 15:22, Greg Parker wrote: >> >>> On Jun 17, 2011, at 2:40 PM, Laurent Daudelin wrote: >>>> One of my user sent me a crash log with an excerpt here: >>>> >>>> ... >>>> Exception Type: EXC_BAD_ACCESS (SIGSEGV) >>>> Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000027 >>>> ... >>>> Thread 4 Crashed: Dispatch queue: com.apple.root.default-priority >>>> 0 libobjc.A.dylib 0x00007fff85ea115c objc_msgSend_vtable2 >>>> + 12 >>>> 1 com.apple.Foundation 0x00007fff827f79a5 -[NSCFString >>>> isEqualToString:] + 63 >>>> ... >>>> >>>> It's a part of my code that compares NSStrings. Of course, nobody besides >>>> him are able to reproduce this. >>>> >>>> My question: what could cause a crash in function 'objc_msgSend_vtable2'? >>> >>> Short answer: for any of the same reasons that cause a crash in >>> objc_msgSend(). >>> >>> The vtable versions of objc_msgSend() are specialized optimizations for a >>> few of the most frequently-called methods. objc_msgSend_vtable2 is >>> currently optimizing the -class method. Presumably one of the two string >>> objects was invalid and -isEqualToString: was trying to check which class >>> the bad object belonged to. >> >> Thanks for the speedy reply, Greg. What do you mean exactly by "invalid"? >> Bad pointers? Pointers on instances of different classes? Or both? > > > Pointer to anything that is not a valid object. Merely being an instance of > the wrong class would not cause that crash.
Thanks for that valuable information, Greg. At least I know where to look. Cheers! -Laurent. -- Laurent Daudelin AIM/iChat/Skype:LaurentDaudelin http://www.nemesys-soft.com/ Logiciels Nemesys Software laur...@nemesys-soft.com _______________________________________________ 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
