site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Short answer: (1) It's protected by #ifdef __ppc__, so it's PPC only (3) The atual implementaiton is as an external symbol in the Libkern and System6.0 exports for PPC only So to get at it you will need to be linked against the kernel (you will need to be either kernel code or a KEXT), you will need to be running PPC-only, and you will need to declare an explicit dependency for your KEXT on an exported symbol set or on the entire kernel. If you use nm /usr/lib/libSystem.B.dylib you can probably answer these questions for yourself. I would recommend you restrict yourself to supported interfaces. -- Terry _______________________________________________ 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... On Apr 28, 2008, at 4:31 AM, Army Research Lab wrote: On 4/24/08 3:17 PM, "Terry Lambert" <tlambert@apple.com> wrote: (2) It's in a header <libkern/OSAtomic.h>, so you should only _expect_ to be able to use it in the kernel; the fact that there are some inline functions there notwithstanding OK, are there spinlocks in user space? I want to try a couple of experiments with some code, just to see if pthread_mutex_lock() is better, or if spinlocking is better. For things for which there are not exported prototypes in header files, there is no explicit support for them. So technically, i386 has OSAtomicEnqueue(), spin_lock(), et. al., but they are not supported, as such. You can see their source code in the published Darwin Libc sources. The pthread_mutex() is going to be heavier weight than spin locks, but spin locks spin, which means they will meaninglessly burn CPU cycles, so "better" is really going to depend on your definition; if you care about battery life and hold them a long time, the answer will be "no", and if you are single CPU, the answer may be "they will just cause you to deadlock". Any spin lock you use, or OSAtomicEnqueue, etc., is probably not going to be desirable to use in any PTHREAD_SCOPE_SYSTEM rather than PTHREAD_SCOPE_PROCESS object. Also, if you want to take an atomicqueue discussion and go off talking about spin locks, you probably ought to either change the subject to reflect a general interest in synchronization primitives, or to explicitly talk about that instead, or the information isn't going to be indexed properly and someone coming after you is just going to ask the same questions again. This email sent to site_archiver@lists.apple.com