site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Importance: Normal User-agent: SquirrelMail/1.4.2 Hi all, in my app, some threads that cannot be detached a-priori : sometimes, they have to be joinable, but sometimes they can be detached (no other thread will wait for them). At the same time, I needed to be sure that storage of all the thread are reclaimed when they terminate. I set up a solution on Linux that ran properly. On linux, I always detached the thread that may be joined JUST BEFORE it exists. In case this thread was not awaited (no pending call to pthread_join() by another thread), its storage was reclaimed when terminating. In case this thread was already awaited (joined) by another thread, the pthread_join in the other thread resulted in a error EINVAL indicating that the thread was detached. However, the storage was still reclaimed when terminating, and the pthread_join exited when the joined thread terminates (or just before). In a few words, it was 'OK'. Here is an example of the code : // THREAD 1 routine // (thread 1 pthread_t is thread1_id) void thread1_routine(void *data) { // do some work // wait for thread 2 // As an example, thread2 is here always joined. // However, in my app, it is joined only in some cases int res = pthread_join(thread2_id, NULL); // in case the thread2 was not already terminated, EINVAL is returned... // in case the thread2 wa already terminated, ESRCH is returned... if( res != 0) { switch(res) { case ESRCH : printf("pthread_join error the thread is not valid\n"); break; case EINVAL : printf("the thread is already detached\n"); break; case EDEADLK : printf("called by the calling thread\n"); break; default : couterr <<"unknown"<<endl; break; } } } // THREAD 2 routine // (thread 2 pthread_t is thread2_id) void thread2_routine(void *data) { // do some work // before terminating, detach the thread to be sure its storage is reclaimed int res = pthread_detach(thread2_id, NULL); if( res != 0) { switch(res) { case ESRCH : printf("the thread is not valid \n"); break; case EINVAL : printf("the thread is already detached\n); break; } pthread_exit(NULL); } As far as I chercked, a code like this one does not run on mac os X. The call to pthread_join results in : mach_port_mod_refs(reply_port) failed: (os/kern) invalid name mach_port_deallocate(kernel_thread) failed: (os/kern) invalid name and sometimes in : mach_port_deallocate(kernel_thread) failed: (os/kern) invalid name *** malloc[1243]: Deallocation of a pointer not malloced: 0x580bc00; This could be a double free(), or free() called with the middle of an allocated block; Try setting environment variable MallocHelp to see tools to help debug (then, the program aborts). Indeed, it seems that we cannot call pthread_detach on a thread while this thread is already by another thread awaited within a pthread_join. Is that true ? If it is, well... It is not documented in the man pages... Does it correspond with the POSIX standard, or should I register it as a bug ? Thx, Nicolas _______________________________________________ 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... This email sent to site_archiver@lists.apple.com