site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com On Nov 4, 2007, at 6:12 PM, Jay Reynolds Freeman wrote: [...] What I see is a failure in thread zero of my app -- that's the one where GUI I/O is done, always deep inside a display or displayIfNeeded of my main window. The actual crash is an EXC_BAD_ACCESS with code KERN_PROTECTION_FAILURE in a function called szone_free, in libSystem.B.dylib. So I am wondering if failure to open this Mach port (I don't know what it is actually for, by the way) is in some way causing this extremely rare failure. It's quite unlikely. I'd look for the usual malloc debugging tools (Guard Malloc, various malloc options found in man malloc). Run your code with those debugging help enabled. Eric _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... Crashes in szone_free() tend to be due to memory corruption. Occam's razor says there is a memory smasher somewhere in your code, a malloc/free usage error and/or a race leading to one of those. [...] If anyone is still reading, do you have a sense of whether I am on the right track? Any ideas for a fix? Any ideas for how to instrument and test to see if I can better understand what is going on? [Off topic for the list] Launching multiple copies of an OS X application is rarely a good idea. If possible, I'd recommend one UI process and multiple UI-less processes. But that's not relevant to Darwin-Dev. This email sent to site_archiver@lists.apple.com