March 2012 - Darwin-dev - lists.apple.com

Re: Missing in sigaction
by Tilghman Lesher 27 Mar '12

27 Mar '12

On Tue, Mar 27, 2012 at 1:57 PM, Nat! <nat(a)mulle-kybernetik.com> wrote: > instead of many words, here's the output of two program runs once with a sleep( 2) - as in seconds, not as in man - commented in and out. What I believe this demonstrates, is that on Darwin (Kernel Version 10.8.0), blocked signal information is lost, which is incovenient. gdb has a similiar problem. > > Or it shows that I am misunderstanding something ;) > > The problem is not that the signal is occurring less often, that's expected, but that the struct __siginfo has trouble remembering things. You really should read the manpage for sigaction, in particular, the section that reads: "In general though, signal handlers should do little more than set a flag; most other actions are not safe." Note, also, that printf() is not in the list of "safe" functions to call. Thus your call to p_log is defined as not safe. While sleep() is safe to call, it also violates one of the cardinal rules of signal handlers -- do only what is necessary to flag that a signal occurred, and do not take more time than is necessary. The actual handling of what the signal represents should be done in a main thread. -Tilghman _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Missing in sigaction
by Nat! 27 Mar '12

27 Mar '12

Hi instead of many words, here's the output of two program runs once with a sleep( 2) - as in seconds, not as in man - commented in and out. What I believe this demonstrates, is that on Darwin (Kernel Version 10.8.0), blocked signal information is lost, which is incovenient. gdb has a similiar problem. Or it shows that I am misunderstanding something ;) The problem is not that the signal is occurring less often, that's expected, but that the struct __siginfo has trouble remembering things. Ciao Nat! Run #1 (without sleep(2) in signal_action) 993: sigaction 993: fork 993: fork 993: wait 994: kill 994: sleep 993: signal 30 from { 30, 0, 0, 994 } 995: kill 995: sleep 993: signal 30 from { 30, 0, 0, 995 } 994: kill 994: sleep 993: signal 30 from { 30, 0, 0, 994 } 995: kill 995: sleep 993: signal 30 from { 30, 0, 0, 995 } 994: _exit 995: _exit 993: wait 993: _exit Run #2 (with sleep( 2) in signal_action) 973: sigaction 973: fork 973: fork 973: wait 974: kill 974: sleep 973: signal 30 from { 30, 0, 0, 974 } 973: sleep 975: kill 975: sleep 974: kill 974: sleep 975: kill 975: sleep 973: signal 30 from { 30, 0, 0, 0 } <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< 974: _exit 973: sleep 975: _exit 973: wait 973: _exit Source code. #include <errno.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> static void p_log( char *s) { printf( "%d: %s\n", getpid(), s); } static void signal_action( int signal, struct __siginfo *info, void *data) { printf( "%d: signal %d from { %d, %d, %d, %d }\n", getpid(), signal, info->si_signo, info->si_errno, info->si_code, info->si_pid); /// COMMENT-UNCOMMENT /// p_log( "sleep"); sleep( 2); } static void _test( void) { p_log( "fork"); if( ! fork()) { p_log( "kill"); kill( getppid(), SIGUSR1); p_log( "sleep"); sleep( 1); p_log( "kill"); kill( getppid(), SIGUSR1); p_log( "sleep"); sleep( 1); p_log( "_exit"); _exit( 0); } } int main( int argc, const char * argv[]) { struct sigaction act; int status; sigemptyset( &act.sa_mask); act.__sigaction_u.__sa_sigaction = signal_action; act.sa_flags = SA_SIGINFO|SA_RESTART; p_log( "sigaction"); sigaction( SIGUSR1, &act, NULL); _test(); _test(); p_log( "wait"); while( wait( &status) == -1); p_log( "wait"); while( wait( &status) == -1); p_log( "_exit"); _exit( 0); } ------------------------------------------------------ As an ex-Atari employee, who has known both high income and protracted unemployment, I can assure you that nobody should enter programming for the money. -- Chris Crawford _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Re: Location of OpenAL tarball
by Erik Larsson 26 Mar '12

26 Mar '12

Axel Luttgens wrote 2012-03-26 09.54: Le 26 mars 2012 à 03:18, Erik Larsson a écrit : OpenAL has been part of the Mac OS X open source distribution since Mac OS X 10.4. However the download links are all broken for this component on http://www.opensource.apple.com, pointing to non-existing content on http://www.openal.org. All versions point to the broken link: http://www.openal.org/openal_webstf/downloads/openal-0.0.8.tar.gz This particular file is cached by many FTP sites so it can be retrieved in other ways... however I doubt that all versions since Mac OS X 10.4 use the same source version of OpenAL, so does anybody know where to get the source releases for the subsequent versions of OpenAL? Given that the 0.0.8 release represents OpenAL-8, then OpenAL-9, OpenAL-16, OpenAL-29, OpenAL-37, OpenAL-37.2 and OpenAL-46 are missing. Yes! This is one of those questions I always wanted to ask, but never dared to. :-) Should I be scared to ask this question? :-) Since many years, I never managed to find on the openal site the strict equivalent of what would have been one of those OpenAL-8, OpenAL-9... tarballs. Regards, - Erik _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com Any kind of hint would do... for instance the exact SVN revisions of these OpenAL versions so the state can be recreated. Although I can't even check out OpenAL from the official SVN at svn://connect.creativelabs.com/OpenAL due to some error messages that hint at some script assuming I'm on a Windows system.

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Re: Location of OpenAL tarball
by Axel Luttgens 26 Mar '12

26 Mar '12

Le 26 mars 2012 à 03:18, Erik Larsson a écrit : > Hi, > > OpenAL has been part of the Mac OS X open source distribution since Mac OS X 10.4. However the download links are all broken for this component on http://www.opensource.apple.com, pointing to non-existing content on http://www.openal.org. > > All versions point to the broken link: http://www.openal.org/openal_webstf/downloads/openal-0.0.8.tar.gz > > This particular file is cached by many FTP sites so it can be retrieved in other ways... however I doubt that all versions since Mac OS X 10.4 use the same source version of OpenAL, so does anybody know where to get the source releases for the subsequent versions of OpenAL? > > Given that the 0.0.8 release represents OpenAL-8, then OpenAL-9, OpenAL-16, OpenAL-29, OpenAL-37, OpenAL-37.2 and OpenAL-46 are missing. Yes! This is one of those questions I always wanted to ask, but never dared to. :-) Since many years, I never managed to find on the openal site the strict equivalent of what would have been one of those OpenAL-8, OpenAL-9... tarballs. TIA, Axel _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Location of OpenAL tarball
by Erik Larsson 26 Mar '12

26 Mar '12

Hi, Regards, - Erik _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com OpenAL has been part of the Mac OS X open source distribution since Mac OS X 10.4. However the download links are all broken for this component on http://www.opensource.apple.com, pointing to non-existing content on http://www.openal.org. All versions point to the broken link: http://www.openal.org/openal_webstf/downloads/openal-0.0.8.tar.gz This particular file is cached by many FTP sites so it can be retrieved in other ways... however I doubt that all versions since Mac OS X 10.4 use the same source version of OpenAL, so does anybody know where to get the source releases for the subsequent versions of OpenAL? Given that the 0.0.8 release represents OpenAL-8, then OpenAL-9, OpenAL-16, OpenAL-29, OpenAL-37, OpenAL-37.2 and OpenAL-46 are missing.

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Re: Sudden and hard to reproduce crashes in libcache
by Dragan Milić 13 Mar '12

13 Mar '12

Just an update on this issue: On uto 21.02.2012., at 14.48, Dragan Milić wrote: > I'm using higher level NSCache API to cache objects. Cached objects are various image representations and much rarely attributed strings and NSNumber instances. I see the crash happens after CFRelease() call, but I can't figure out why. If I try to do CFRelease(NULL), I get almost the same sequence, similar to: > > 3 libc++abi.dylib 0x00007fff8a1e77bc abort_message + 214 > 4 libc++abi.dylib 0x00007fff8a1e4fcf default_terminate() + 28 > 5 libobjc.A.dylib 0x00007fff8a69a1b9 _objc_terminate + 94 > 6 libc++abi.dylib 0x00007fff8a1e5001 safe_handler_caller(void (*)()) + 11 > 7 libc++abi.dylib 0x00007fff8a1e505c std::terminate() + 16 > 8 libc++abi.dylib 0x00007fff8a1e6152 __cxa_throw + 114 > 9 libobjc.A.dylib 0x00007fff8a699e7a objc_exception_throw + 327 > 10 com.apple.CoreFoundation 0x00007fff8c8b92a9 -[NSException raise] + 9 > 11 com.apple.ExceptionHandling 0x0000000100332e0a NSExceptionHandlerUncaughtSignalHandler + 37 > 12 libsystem_c.dylib 0x00007fff900f0cfa _sigtramp + 26 > > But I don't know who and why does (if at all) that NULL pointer release. The documentation for libcache says "Calling cache functions from cache callbacks should be avoided to prevent deadlock." I thought maybe when releasing cached objects libcache calls callback methods to release memory and then image representations are doing some caching on their own, which would effectively be calling cache functions from cache callbacks. But this is just a wild guess, I've no idea what is really going on. > > So, I'd really appreciate if anyone can help me with this. I've got no idea whether it's a but in the application, or the OS. If necessary, I can send the full crash report and also explain what object are being cached using NSCache. Apparently, it's a bug in NSCache. On http://files.me.com/milke/t5ufx5 can you find a super simple sample app to reproduce it every time without any problem. It looks like -[NSString stringWithFormat:] (and possibly other calls) can return the same pointer rather than creating new object every call. Perhaps it's trying to reuse strings to save memory? NSCache seems not to like that and crashes. If I wrap the strings in a simple holder object, which has nothing more than a string as it's content ivar, that solves the crashing problem. But it's still completely incorrect behaviour on NSCache part. I think this makes NSCache (at the moment) almost unusable in real world applications, because you never now whether and when it's going to crash. Maybe never, maybe immediately. I encourage everyone (especially those using NSCache) to file a bug report to Apple. If they get a lot of duplicates on the same issue, they may hopefully do something quicker. NSCache was introduced for object caching and memory saving and having to wrap every cached object in a holder object defies cache's purpose (kind of). -- Dragan _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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Open Source Release
by William Siegrist 09 Mar '12

09 Mar '12

The open source components of iOS 5.1 have been released. http://www.opensource.apple.com/release/ios-51/ Thanks, -Bill _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.ap… This email sent to site_archiver(a)lists.apple.com

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