Author: ed Date: Tue Aug 11 13:47:23 2015 New Revision: 286631 URL: https://svnweb.freebsd.org/changeset/base/286631
Log: Add support for anonymous kqueues. CloudABI's polling system calls merge the concept of one-shot polling (poll, select) and stateful polling (kqueue). They share the same data structures. Extend FreeBSD's kqueue to provide support for waiting for events on an anonymous kqueue. Unlike stateful polling, there is no need to support timeouts, as an additional timer event could be used instead. Furthermore, it makes no sense to use a different number of input and output kevents. Merge this into a single argument. Obtained from: https://github.com/NuxiNL/freebsd Differential Revision: https://reviews.freebsd.org/D3307 Modified: head/sys/kern/kern_event.c head/sys/sys/syscallsubr.h Modified: head/sys/kern/kern_event.c ============================================================================== --- head/sys/kern/kern_event.c Tue Aug 11 13:42:58 2015 (r286630) +++ head/sys/kern/kern_event.c Tue Aug 11 13:47:23 2015 (r286631) @@ -99,6 +99,8 @@ static int kqueue_register(struct kqueue struct thread *td, int waitok); static int kqueue_acquire(struct file *fp, struct kqueue **kqp); static void kqueue_release(struct kqueue *kq, int locked); +static void kqueue_destroy(struct kqueue *kq); +static void kqueue_drain(struct kqueue *kq, struct thread *td); static int kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident, int waitok); static void kqueue_task(void *arg, int pending); @@ -741,6 +743,16 @@ sys_kqueue(struct thread *td, struct kqu return (kern_kqueue(td, 0, NULL)); } +static void +kqueue_init(struct kqueue *kq) +{ + + mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF | MTX_DUPOK); + TAILQ_INIT(&kq->kq_head); + knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); + TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); +} + int kern_kqueue(struct thread *td, int flags, struct filecaps *fcaps) { @@ -766,12 +778,9 @@ kern_kqueue(struct thread *td, int flags /* An extra reference on `fp' has been held for us by falloc(). */ kq = malloc(sizeof *kq, M_KQUEUE, M_WAITOK | M_ZERO); - mtx_init(&kq->kq_lock, "kqueue", NULL, MTX_DEF|MTX_DUPOK); - TAILQ_INIT(&kq->kq_head); + kqueue_init(kq); kq->kq_fdp = fdp; kq->kq_cred = cred; - knlist_init_mtx(&kq->kq_sel.si_note, &kq->kq_lock); - TASK_INIT(&kq->kq_task, 0, kqueue_task, kq); FILEDESC_XLOCK(fdp); TAILQ_INSERT_HEAD(&fdp->fd_kqlist, kq, kq_list); @@ -910,26 +919,20 @@ kern_kevent(struct thread *td, int fd, i return (error); } -int -kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, +static int +kqueue_kevent(struct kqueue *kq, struct thread *td, int nchanges, int nevents, struct kevent_copyops *k_ops, const struct timespec *timeout) { struct kevent keva[KQ_NEVENTS]; struct kevent *kevp, *changes; - struct kqueue *kq; int i, n, nerrors, error; - error = kqueue_acquire(fp, &kq); - if (error != 0) - return (error); - nerrors = 0; - while (nchanges > 0) { n = nchanges > KQ_NEVENTS ? KQ_NEVENTS : nchanges; error = k_ops->k_copyin(k_ops->arg, keva, n); if (error) - goto done; + return (error); changes = keva; for (i = 0; i < n; i++) { kevp = &changes[i]; @@ -938,33 +941,56 @@ kern_kevent_fp(struct thread *td, struct kevp->flags &= ~EV_SYSFLAGS; error = kqueue_register(kq, kevp, td, 1); if (error || (kevp->flags & EV_RECEIPT)) { - if (nevents != 0) { - kevp->flags = EV_ERROR; - kevp->data = error; - (void) k_ops->k_copyout(k_ops->arg, - kevp, 1); - nevents--; - nerrors++; - } else { - goto done; - } + if (nevents == 0) + return (error); + kevp->flags = EV_ERROR; + kevp->data = error; + (void)k_ops->k_copyout(k_ops->arg, kevp, 1); + nevents--; + nerrors++; } } nchanges -= n; } if (nerrors) { td->td_retval[0] = nerrors; - error = 0; - goto done; + return (0); } - error = kqueue_scan(kq, nevents, k_ops, timeout, keva, td); -done: + return (kqueue_scan(kq, nevents, k_ops, timeout, keva, td)); +} + +int +kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, + struct kevent_copyops *k_ops, const struct timespec *timeout) +{ + struct kqueue *kq; + int error; + + error = kqueue_acquire(fp, &kq); + if (error != 0) + return (error); + error = kqueue_kevent(kq, td, nchanges, nevents, k_ops, timeout); kqueue_release(kq, 0); return (error); } int +kern_kevent_anonymous(struct thread *td, int nevents, + struct kevent_copyops *k_ops) +{ + struct kqueue kq = {}; + int error; + + kqueue_init(&kq); + kq.kq_refcnt = 1; + error = kqueue_kevent(&kq, td, nevents, nevents, k_ops, NULL); + kqueue_drain(&kq, td); + kqueue_destroy(&kq); + return (error); +} + +int kqueue_add_filteropts(int filt, struct filterops *filtops) { int error; @@ -1734,21 +1760,12 @@ kqueue_stat(struct file *fp, struct stat return (0); } -/*ARGSUSED*/ -static int -kqueue_close(struct file *fp, struct thread *td) +static void +kqueue_drain(struct kqueue *kq, struct thread *td) { - struct kqueue *kq = fp->f_data; - struct filedesc *fdp; struct knote *kn; int i; - int error; - int filedesc_unlock; - - if ((error = kqueue_acquire(fp, &kq))) - return error; - filedesc_unlock = 0; KQ_LOCK(kq); KASSERT((kq->kq_state & KQ_CLOSING) != KQ_CLOSING, @@ -1758,7 +1775,6 @@ kqueue_close(struct file *fp, struct thr msleep(&kq->kq_refcnt, &kq->kq_lock, PSOCK, "kqclose", 0); KASSERT(kq->kq_refcnt == 1, ("other refs are out there!")); - fdp = kq->kq_fdp; KASSERT(knlist_empty(&kq->kq_sel.si_note), ("kqueue's knlist not empty")); @@ -1809,6 +1825,36 @@ kqueue_close(struct file *fp, struct thr } KQ_UNLOCK(kq); +} + +static void +kqueue_destroy(struct kqueue *kq) +{ + + seldrain(&kq->kq_sel); + knlist_destroy(&kq->kq_sel.si_note); + mtx_destroy(&kq->kq_lock); + + if (kq->kq_knhash != NULL) + free(kq->kq_knhash, M_KQUEUE); + if (kq->kq_knlist != NULL) + free(kq->kq_knlist, M_KQUEUE); + + funsetown(&kq->kq_sigio); +} + +/*ARGSUSED*/ +static int +kqueue_close(struct file *fp, struct thread *td) +{ + struct kqueue *kq = fp->f_data; + struct filedesc *fdp; + int error; + int filedesc_unlock; + + if ((error = kqueue_acquire(fp, &kq))) + return error; + kqueue_drain(kq, td); /* * We could be called due to the knote_drop() doing fdrop(), @@ -1816,6 +1862,7 @@ kqueue_close(struct file *fp, struct thr * lock is owned, and filedesc sx is locked before, to not * take the sleepable lock after non-sleepable. */ + fdp = kq->kq_fdp; if (!sx_xlocked(FILEDESC_LOCK(fdp))) { FILEDESC_XLOCK(fdp); filedesc_unlock = 1; @@ -1825,17 +1872,7 @@ kqueue_close(struct file *fp, struct thr if (filedesc_unlock) FILEDESC_XUNLOCK(fdp); - seldrain(&kq->kq_sel); - knlist_destroy(&kq->kq_sel.si_note); - mtx_destroy(&kq->kq_lock); - kq->kq_fdp = NULL; - - if (kq->kq_knhash != NULL) - free(kq->kq_knhash, M_KQUEUE); - if (kq->kq_knlist != NULL) - free(kq->kq_knlist, M_KQUEUE); - - funsetown(&kq->kq_sigio); + kqueue_destroy(kq); chgkqcnt(kq->kq_cred->cr_ruidinfo, -1, 0); crfree(kq->kq_cred); free(kq, M_KQUEUE); Modified: head/sys/sys/syscallsubr.h ============================================================================== --- head/sys/sys/syscallsubr.h Tue Aug 11 13:42:58 2015 (r286630) +++ head/sys/sys/syscallsubr.h Tue Aug 11 13:47:23 2015 (r286631) @@ -124,6 +124,8 @@ int kern_jail_get(struct thread *td, str int kern_jail_set(struct thread *td, struct uio *options, int flags); int kern_kevent(struct thread *td, int fd, int nchanges, int nevents, struct kevent_copyops *k_ops, const struct timespec *timeout); +int kern_kevent_anonymous(struct thread *td, int nevents, + struct kevent_copyops *k_ops); int kern_kevent_fp(struct thread *td, struct file *fp, int nchanges, int nevents, struct kevent_copyops *k_ops, const struct timespec *timeout); _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
