Re: Catching signal errors
site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Matt Watson wrote: write(1, sig_message, sizeof(sig_message)); exit(1); } Thanks everyone!!!! #define kMySigError -9999 void fatalSigHandler(int sig, siginfo_t* info, void* context) { short pErr = kMySigError; throw(pErr); _Exit(1); //Not that this will ever be reached } main(){ Ptr ptrFoo = nil; char barrrr; installSignalHandler(SIGSEGV, &fatalSigHandler); installSignalHandler(SIGBUS, &fatalSigHandler); try{ barrrr = (*ptrFoo); }catch(short err){ printf("Error %x", err); } ....continue return(noErr); } Rick _______________________________________________ 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... void fatalSigHandler(int sig, siginfo_t* info, void* context) { // We are very limited in what we are allowed to do in a signal handler. // Memory should not be allocated, and most libc functions should not be used. static char sig_message[] = "Aborting: Fatal signal occurred!\n"; Never call exit() from a signal handler. You want _Exit() instead. exit() will call atexit() handlers which will are likely not signal-safe. And you probably want to use fd 2 (stderr), instead of fd 1 in the write() call. Good suggestions. That's especially important when using dlopen or NSLinkModule on libraries. They could cause further signals or even signal deadlocks when they get unloaded. That said: if you're not going to add any more info in your signal handler, or do any cleanup like unlink() files, it may just be best to let it crash and generate a crash log. I assumed that he'd replace the handler with something else. One of the handlers I have for a project calls execv() to restart the daemon in case of a crash. That is after writing errors to a log and closing open file handles/resetting signal masks (as they are both inherited by the new process), and doing some other general cleanup of the daemon's lock/state files. -Kevin- I hope no one minds if I take this one step further. Is there actually a way to have it return to the offending code with an exception triggered? For example, would the following snippet work... This email sent to site_archiver@lists.apple.com
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Rick Steele