On Wed, 9 Jan 2008 02:35:32 -0800 (PST) [EMAIL PROTECTED] wrote: > To Whom It May Concern, > > After I patched my 2.6.23 kernel to 2.6.24-rc7 this morning, I noticed > some odd behavior with respect to POSIX threads in a test program I had > written (originally to test epoll.) > > The behavior is as follows: > > 1. main() creates a new thread of execution with pthread_create > 2. thread_func() immediately calls pthread_detach(), which is supposed to > ensure that thread resources are cleaned up when the thread terminates. > 3. The spawned thread sleeps and then prints a message "got here" > 4. The main thread calls pthread_join(). According to the POSIX > documentation, this should suspend execution until the spawned thread has > terminated. > > What I'm seeing is that the main thread terminates immediately. If I > comment out the call to pthread_detach(), the program runs normally. If I > boot with my 2.6.23 kernel, the program runs normally. > > I'm not sure if this is some oversight on my part but similar programs > operate correctly on my Debian etch installation with 2.6.18 as well as > with the newer 23 kernel, but not with the patch. > > If you have any questions, don't hesitate to email me; my address is > provided below. > > See Attached (bug.c) > > Tom R. Dial > [EMAIL PROTECTED]
Hello Tom Your program is buggy and depends on scheduling policies. To make it fails on 2.6.23 (or say 2.6.9) too, just add a sleep(1) before pthread_join() call Once a thread calls pthread_detach(pthread_t this_id), it's not possible anymore to pthread_join(this_id, &ret) or effect is undefined. (quoting POSIX : "The results of multiple simultaneous calls to pthread_join() specifying the same target thread are undefined" ) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
