site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com Hi, On 12/6/05, Eric Welch <ericw@innosys.com> wrote: Miguel, For some time OSX has had Posix thread support including semaphores. -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... On Dec 6, 2005, at 12:30 PM, Miguel Filipe wrote: In that case, my app has a very strange behaviour on OSX, I make use of sem_init(), sem_wait() & sem_post(), and in OSX my threads never wait on sem_wait(). MacOS X supports named POSIX semaphores, but not unnamed POSIX semaphores. I expect you must be trapping SIGSYS to prevent your program exiting because of an unsupported system call on the call to sem_init(), since it's implementation is a return of the error ENOSYS. I googled after that problem and saw a lot of "OSX doesn't support POSIX Semaphores", after which I irresponsibly stopped looking for the cause of the problem. Apparently that could be the case in OSX 10.3, but I'm using 10.4. Is there any kind of peculiarity in how I should use posix semaphores? (header files, semaphore inicialization or linker flags...) The first thing you should do is #include <unistd.h> and conditionalize your use of POSIX semaphores on the manifest constant _POSIX_SEMAPHORES, e.g.: #if ((_POSIX_SEMAPHORES - 200112L) >= 0) /* This platform fully supports POSIX semaphores */ #else #if defined(__APPLE__) /* This platform can support POSIX named semaphores, but not unnamed semaphores */ #else /* this platform requires that I Google code for P/V semaphores and include it here */ #endif #endif The proper list was more likely "unix-porting", but that's OK; this question comes up from time to time. This email sent to site_archiver@lists.apple.com