On Tue, 2 Jul 2002, Jonathan Lemon wrote: > In article <local.mail.freebsd-current/[EMAIL PROTECTED]> you >write: > >In message <[EMAIL PROTECTED]>, Ju > >lian Elischer writes: > >>The big problem at the moment is that something in the > >>source tree as a whole, and probably something that came in with KSE > >>is stopping us from successfully compiling a working libc_r. > >>(a bit ironic really). > > > >Is the new > > > > (elm)->field.tqe_next = (void *)-1; > > > >in TAILQ_REMOVE a likely candidate? That could easily tickle old > >bugs in other code. The libc_r code does use a lot of TAILQ macros. > > >From casual inspection of the sources, it appears this may be the case: > > uthread/pthread_private.h: > #define PTHREAD_WORKQ_REMOVE(thrd) do { \ > TAILQ_REMOVE(&_workq,thrd,qe); \ > (thrd)->flags &= ~PTHREAD_FLAGS_IN_WORKQ; \ > } while (0) > > uthread/uthread_kern.c (in multiple locations): > TAILQ_FOREACH(pthread, &_workq, qe) { > .... > PTHREAD_WORKQ_REMOVE(pthread); > }
This used to be safe as long as the element removed wasn't re-added to another queue using the same link. There are other places in libc_r where we do re-use the same link (remove from one list and add to another), but roll our own loop in that case: for (p = TAILQ_FIRST(&q); p != NULL; p = p_next) { p_next = TAILQ_NEXT(p, p_qe); ... TAILQ_REMOVE(&q, pthread, p_qe); ... } -- Dan Eischen To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message