diff options
Diffstat (limited to 'src/nxt_devpoll.c')
| -rw-r--r-- | src/nxt_devpoll.c | 699 |
1 files changed, 699 insertions, 0 deletions
diff --git a/src/nxt_devpoll.c b/src/nxt_devpoll.c new file mode 100644 index 00000000..8fbe8184 --- /dev/null +++ b/src/nxt_devpoll.c @@ -0,0 +1,699 @@ + +/* + * Copyright (C) Igor Sysoev + * Copyright (C) NGINX, Inc. + */ + +#include <nxt_main.h> + + +/* + * "/dev/poll" has been introduced in Solaris 7 (11/99), HP-UX 11.22 (named + * "eventport pseudo driver" internally, not to be confused with Solaris 10 + * event ports), IRIX 6.5.15, and Tru64 UNIX 5.1A. + * + * Although "/dev/poll" descriptor is a file descriptor, nevertheless + * it cannot be added to another poll set, Solaris poll(7d): + * + * The /dev/poll driver does not yet support polling. Polling on a + * /dev/poll file descriptor will result in POLLERR being returned + * in the revents field of pollfd structure. + */ + + +#define NXT_DEVPOLL_ADD 0 +#define NXT_DEVPOLL_UPDATE 1 +#define NXT_DEVPOLL_CHANGE 2 +#define NXT_DEVPOLL_DELETE 3 + + +static nxt_event_set_t *nxt_devpoll_create(nxt_event_signals_t *signals, + nxt_uint_t mchanges, nxt_uint_t mevents); +static void nxt_devpoll_free(nxt_event_set_t *event_set); +static void nxt_devpoll_enable(nxt_event_set_t *event_set, nxt_event_fd_t *ev); +static void nxt_devpoll_disable(nxt_event_set_t *event_set, nxt_event_fd_t *ev); +#if (NXT_HPUX) +static void nxt_devpoll_close(nxt_event_set_t *event_set, nxt_event_fd_t *ev); +static void nxt_devpoll_drop_changes(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +#endif +static void nxt_devpoll_enable_read(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +static void nxt_devpoll_enable_write(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +static void nxt_devpoll_disable_read(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +static void nxt_devpoll_disable_write(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +static void nxt_devpoll_block_read(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +static void nxt_devpoll_block_write(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +static void nxt_devpoll_oneshot_read(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +static void nxt_devpoll_oneshot_write(nxt_event_set_t *event_set, + nxt_event_fd_t *ev); +static void nxt_devpoll_change(nxt_event_set_t *event_set, nxt_event_fd_t *ev, + nxt_uint_t op, nxt_uint_t events); +static nxt_int_t nxt_devpoll_commit_changes(nxt_thread_t *thr, + nxt_devpoll_event_set_t *ds); +static void nxt_devpoll_change_error(nxt_thread_t *thr, + nxt_devpoll_event_set_t *ds, nxt_event_fd_t *ev); +static void nxt_devpoll_remove(nxt_thread_t *thr, nxt_devpoll_event_set_t *ds, + nxt_fd_t fd); +static nxt_int_t nxt_devpoll_write(nxt_thread_t *thr, int devpoll, + struct pollfd *pfd, size_t n); +static void nxt_devpoll_set_poll(nxt_thread_t *thr, nxt_event_set_t *event_set, + nxt_msec_t timeout); + + +const nxt_event_set_ops_t nxt_devpoll_event_set = { + "devpoll", + nxt_devpoll_create, + nxt_devpoll_free, + nxt_devpoll_enable, + nxt_devpoll_disable, + nxt_devpoll_disable, +#if (NXT_HPUX) + nxt_devpoll_close, +#else + nxt_devpoll_disable, +#endif + nxt_devpoll_enable_read, + nxt_devpoll_enable_write, + nxt_devpoll_disable_read, + nxt_devpoll_disable_write, + nxt_devpoll_block_read, + nxt_devpoll_block_write, + nxt_devpoll_oneshot_read, + nxt_devpoll_oneshot_write, + nxt_devpoll_enable_read, + NULL, + NULL, + NULL, + NULL, + nxt_devpoll_set_poll, + + &nxt_unix_event_conn_io, + + NXT_NO_FILE_EVENTS, + NXT_NO_SIGNAL_EVENTS, +}; + + +static nxt_event_set_t * +nxt_devpoll_create(nxt_event_signals_t *signals, nxt_uint_t mchanges, + nxt_uint_t mevents) +{ + nxt_event_set_t *event_set; + nxt_devpoll_event_set_t *ds; + + event_set = nxt_zalloc(sizeof(nxt_devpoll_event_set_t)); + if (event_set == NULL) { + return NULL; + } + + ds = &event_set->devpoll; + + ds->devpoll = -1; + ds->mchanges = mchanges; + ds->mevents = mevents; + + ds->devpoll_changes = nxt_malloc(sizeof(nxt_devpoll_change_t) * mchanges); + if (ds->devpoll_changes == NULL) { + goto fail; + } + + /* + * NXT_DEVPOLL_CHANGE requires two struct pollfd's: + * for POLLREMOVE and subsequent POLLIN or POLLOUT. + */ + ds->changes = nxt_malloc(2 * sizeof(struct pollfd) * mchanges); + if (ds->changes == NULL) { + goto fail; + } + + ds->events = nxt_malloc(sizeof(struct pollfd) * mevents); + if (ds->events == NULL) { + goto fail; + } + + ds->devpoll = open("/dev/poll", O_RDWR); + if (ds->devpoll == -1) { + nxt_main_log_emerg("open(/dev/poll) failed %E", nxt_errno); + goto fail; + } + + nxt_main_log_debug("open(/dev/poll): %d", ds->devpoll); + + return event_set; + +fail: + + nxt_devpoll_free(event_set); + + return NULL; +} + + +static void +nxt_devpoll_free(nxt_event_set_t *event_set) +{ + nxt_devpoll_event_set_t *ds; + + ds = &event_set->devpoll; + + nxt_main_log_debug("devpoll %d free", ds->devpoll); + + if (ds->devpoll != -1) { + if (close(ds->devpoll) != 0) { + nxt_main_log_emerg("devpoll close(%d) failed %E", + ds->devpoll, nxt_errno); + } + } + + nxt_free(ds->events); + nxt_free(ds->changes); + nxt_free(ds->devpoll_changes); + nxt_event_set_fd_hash_destroy(&ds->fd_hash); + nxt_free(ds); +} + + +static void +nxt_devpoll_enable(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + ev->read = NXT_EVENT_DEFAULT; + ev->write = NXT_EVENT_DEFAULT; + + nxt_devpoll_change(event_set, ev, NXT_DEVPOLL_ADD, POLLIN | POLLOUT); +} + + +/* + * Solaris does not automatically remove a closed file descriptor from + * a "/dev/poll" set: ioctl(DP_ISPOLLED) for the descriptor returns 1, + * significative of active descriptor. POLLREMOVE can remove already + * closed file descriptor, so the removal can be batched, Solaris poll(7d): + * + * When using the "/dev/poll" driver, you should remove a closed file + * descriptor from a monitored poll set. Failure to do so may result + * in a POLLNVAL revents being returned for the closed file descriptor. + * When a file descriptor is closed but not removed from the monitored + * set, and is reused in subsequent open of a different device, you + * will be polling the device associated with the reused file descriptor. + * In a multithreaded application, careful coordination among threads + * doing close and DP_POLL ioctl is recommended for consistent results. + * + * Besides Solaris and HP-UX allow to add invalid descriptors to an + * "/dev/poll" set, although the descriptors are not marked as polled, + * that is, ioctl(DP_ISPOLLED) returns 0. + */ + +static void +nxt_devpoll_disable(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + if (ev->read != NXT_EVENT_INACTIVE || ev->write != NXT_EVENT_INACTIVE) { + + ev->read = NXT_EVENT_INACTIVE; + ev->write = NXT_EVENT_INACTIVE; + + nxt_devpoll_change(event_set, ev, NXT_DEVPOLL_DELETE, POLLREMOVE); + } +} + + +#if (NXT_HPUX) + +/* + * HP-UX poll(7): + * + * When a polled file descriptor is closed, it is automatically + * deregistered. + */ + +static void +nxt_devpoll_close(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + ev->read = NXT_EVENT_INACTIVE; + ev->write = NXT_EVENT_INACTIVE; + + nxt_devpoll_drop_changes(event_set, ev); +} + + +static void +nxt_devpoll_drop_changes(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + nxt_devpoll_change_t *dst, *src, *end; + nxt_devpoll_event_set_t *ds; + + ds = &event_set->devpoll; + + dst = ds->devpoll_changes; + end = dst + ds->nchanges; + + for (src = dst; src < end; src++) { + + if (src->event == ev) { + continue; + } + + if (dst != src) { + *dst = *src; + } + + dst++; + } + + ds->nchanges -= end - dst; +} + +#endif + + +/* + * Solaris poll(7d): + * + * The fd field specifies the file descriptor being polled. The events + * field indicates the interested poll events on the file descriptor. + * If a pollfd array contains multiple pollfd entries with the same fd field, + * the "events" field in each pollfd entry is OR'ed. A special POLLREMOVE + * event in the events field of the pollfd structure removes the fd from + * the monitored set. The revents field is not used. + */ + +static void +nxt_devpoll_enable_read(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + nxt_uint_t op, events; + + if (ev->read != NXT_EVENT_BLOCKED) { + + events = POLLIN; + + if (ev->write == NXT_EVENT_INACTIVE) { + op = NXT_DEVPOLL_ADD; + + } else if (ev->write == NXT_EVENT_BLOCKED) { + ev->write = NXT_EVENT_INACTIVE; + op = NXT_DEVPOLL_CHANGE; + + } else { + op = NXT_DEVPOLL_UPDATE; + events = POLLIN | POLLOUT; + } + + nxt_devpoll_change(event_set, ev, op, events); + } + + ev->read = NXT_EVENT_DEFAULT; +} + + +static void +nxt_devpoll_enable_write(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + nxt_uint_t op, events; + + if (ev->write != NXT_EVENT_BLOCKED) { + + events = POLLOUT; + + if (ev->read == NXT_EVENT_INACTIVE) { + op = NXT_DEVPOLL_ADD; + + } else if (ev->read == NXT_EVENT_BLOCKED) { + ev->read = NXT_EVENT_INACTIVE; + op = NXT_DEVPOLL_CHANGE; + + } else { + op = NXT_DEVPOLL_UPDATE; + events = POLLIN | POLLOUT; + } + + nxt_devpoll_change(event_set, ev, op, events); + } + + ev->write = NXT_EVENT_DEFAULT; +} + + +static void +nxt_devpoll_disable_read(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + nxt_uint_t op, events; + + ev->read = NXT_EVENT_INACTIVE; + + if (ev->write <= NXT_EVENT_BLOCKED) { + ev->write = NXT_EVENT_INACTIVE; + op = NXT_DEVPOLL_DELETE; + events = POLLREMOVE; + + } else { + op = NXT_DEVPOLL_CHANGE; + events = POLLOUT; + } + + nxt_devpoll_change(event_set, ev, op, events); +} + + +static void +nxt_devpoll_disable_write(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + nxt_uint_t op, events; + + ev->write = NXT_EVENT_INACTIVE; + + if (ev->read <= NXT_EVENT_BLOCKED) { + ev->read = NXT_EVENT_INACTIVE; + op = NXT_DEVPOLL_DELETE; + events = POLLREMOVE; + + } else { + op = NXT_DEVPOLL_CHANGE; + events = POLLIN; + } + + nxt_devpoll_change(event_set, ev, op, events); +} + + +static void +nxt_devpoll_block_read(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + if (ev->read != NXT_EVENT_INACTIVE) { + ev->read = NXT_EVENT_BLOCKED; + } +} + + +static void +nxt_devpoll_block_write(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + if (ev->write != NXT_EVENT_INACTIVE) { + ev->write = NXT_EVENT_BLOCKED; + } +} + + +static void +nxt_devpoll_oneshot_read(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + nxt_devpoll_enable_read(event_set, ev); + + ev->read = NXT_EVENT_ONESHOT; +} + + +static void +nxt_devpoll_oneshot_write(nxt_event_set_t *event_set, nxt_event_fd_t *ev) +{ + nxt_devpoll_enable_write(event_set, ev); + + ev->write = NXT_EVENT_ONESHOT; +} + + +static void +nxt_devpoll_change(nxt_event_set_t *event_set, nxt_event_fd_t *ev, + nxt_uint_t op, nxt_uint_t events) +{ + nxt_devpoll_change_t *ch; + nxt_devpoll_event_set_t *ds; + + ds = &event_set->devpoll; + + nxt_log_debug(ev->log, "devpoll %d change fd:%d op:%ui ev:%04Xi", + ds->devpoll, ev->fd, op, events); + + if (ds->nchanges >= ds->mchanges) { + (void) nxt_devpoll_commit_changes(nxt_thread(), ds); + } + + ch = &ds->devpoll_changes[ds->nchanges++]; + ch->op = op; + ch->fd = ev->fd; + ch->events = events; + ch->event = ev; +} + + +static nxt_int_t +nxt_devpoll_commit_changes(nxt_thread_t *thr, nxt_devpoll_event_set_t *ds) +{ + size_t n; + nxt_int_t ret, retval; + struct pollfd *pfd; + nxt_devpoll_change_t *ch, *end; + + nxt_log_debug(thr->log, "devpoll %d changes:%ui", + ds->devpoll, ds->nchanges); + + retval = NXT_OK; + n = 0; + ch = ds->devpoll_changes; + end = ch + ds->nchanges; + + do { + nxt_log_debug(thr->log, "devpoll fd:%d op:%d ev:%04Xd", + ch->fd, ch->op, ch->events); + + if (ch->op == NXT_DEVPOLL_CHANGE) { + pfd = &ds->changes[n++]; + pfd->fd = ch->fd; + pfd->events = POLLREMOVE; + pfd->revents = 0; + } + + pfd = &ds->changes[n++]; + pfd->fd = ch->fd; + pfd->events = ch->events; + pfd->revents = 0; + + ch++; + + } while (ch < end); + + ch = ds->devpoll_changes; + end = ch + ds->nchanges; + + ret = nxt_devpoll_write(thr, ds->devpoll, ds->changes, n); + + if (nxt_slow_path(ret != NXT_OK)) { + do { + nxt_devpoll_change_error(thr, ds, ch->event); + ch++; + } while (ch < end); + + ds->nchanges = 0; + + return NXT_ERROR; + } + + do { + if (ch->op == NXT_DEVPOLL_ADD) { + ret = nxt_event_set_fd_hash_add(&ds->fd_hash, ch->fd, ch->event); + + if (nxt_slow_path(ret != NXT_OK)) { + nxt_devpoll_change_error(thr, ds, ch->event); + retval = NXT_ERROR; + } + + } else if (ch->op == NXT_DEVPOLL_DELETE) { + nxt_event_set_fd_hash_delete(&ds->fd_hash, ch->fd, 0); + } + + /* Nothing tp do for NXT_DEVPOLL_UPDATE and NXT_DEVPOLL_CHANGE. */ + + ch++; + + } while (ch < end); + + ds->nchanges = 0; + + return retval; +} + + +static void +nxt_devpoll_change_error(nxt_thread_t *thr, nxt_devpoll_event_set_t *ds, + nxt_event_fd_t *ev) +{ + ev->read = NXT_EVENT_INACTIVE; + ev->write = NXT_EVENT_INACTIVE; + + nxt_thread_work_queue_add(thr, &thr->work_queue.main, + ev->error_handler, ev, ev->data, ev->log); + + nxt_event_set_fd_hash_delete(&ds->fd_hash, ev->fd, 1); + + nxt_devpoll_remove(thr, ds, ev->fd); +} + + +static void +nxt_devpoll_remove(nxt_thread_t *thr, nxt_devpoll_event_set_t *ds, nxt_fd_t fd) +{ + int n; + struct pollfd pfd; + + pfd.fd = fd; + pfd.events = 0; + pfd.revents = 0; + + n = ioctl(ds->devpoll, DP_ISPOLLED, &pfd); + + nxt_log_debug(thr->log, "ioctl(%d, DP_ISPOLLED, %d): %d", + ds->devpoll, fd, n); + + if (n == 0) { + /* The file descriptor is not in the set. */ + return; + } + + if (n == -1) { + nxt_log_alert(thr->log, "ioctl(%d, DP_ISPOLLED, %d) failed %E", + ds->devpoll, fd, nxt_errno); + /* Fall through. */ + } + + /* n == 1: the file descriptor is in the set. */ + + nxt_log_debug(thr->log, "devpoll %d remove fd:%d", ds->devpoll, fd); + + pfd.fd = fd; + pfd.events = POLLREMOVE; + pfd.revents = 0; + + nxt_devpoll_write(thr, ds->devpoll, &pfd, 1); +} + + +static nxt_int_t +nxt_devpoll_write(nxt_thread_t *thr, int devpoll, struct pollfd *pfd, + size_t n) +{ + nxt_log_debug(thr->log, "devpoll write(%d) changes:%uz", devpoll, n); + + n *= sizeof(struct pollfd); + + if (nxt_slow_path(write(devpoll, pfd, n) == (ssize_t) n)) { + return NXT_OK; + } + + nxt_log_alert(thr->log, "devpoll write(%d) failed %E", + devpoll, nxt_errno); + + return NXT_ERROR; +} + + +static void +nxt_devpoll_set_poll(nxt_thread_t *thr, nxt_event_set_t *event_set, + nxt_msec_t timeout) +{ + int nevents; + nxt_fd_t fd; + nxt_int_t i; + nxt_err_t err; + nxt_uint_t events, level; + struct dvpoll dvp; + struct pollfd *pfd; + nxt_event_fd_t *ev; + nxt_devpoll_event_set_t *ds; + + ds = &event_set->devpoll; + + if (ds->nchanges != 0) { + if (nxt_devpoll_commit_changes(thr, ds) != NXT_OK) { + /* Error handlers have been enqueued on failure. */ + timeout = 0; + } + } + + nxt_log_debug(thr->log, "ioctl(%d, DP_POLL) timeout:%M", + ds->devpoll, timeout); + + dvp.dp_fds = ds->events; + dvp.dp_nfds = ds->mevents; + dvp.dp_timeout = timeout; + + nevents = ioctl(ds->devpoll, DP_POLL, &dvp); + + err = (nevents == -1) ? nxt_errno : 0; + + nxt_thread_time_update(thr); + + nxt_log_debug(thr->log, "ioctl(%d, DP_POLL): %d", ds->devpoll, nevents); + + if (nevents == -1) { + level = (err == NXT_EINTR) ? NXT_LOG_INFO : NXT_LOG_ALERT; + nxt_log_error(level, thr->log, "ioctl(%d, DP_POLL) failed %E", + ds->devpoll, err); + return; + } + + for (i = 0; i < nevents; i++) { + + pfd = &ds->events[i]; + fd = pfd->fd; + events = pfd->revents; + + ev = nxt_event_set_fd_hash_get(&ds->fd_hash, fd); + + if (nxt_slow_path(ev == NULL)) { + nxt_log_alert(thr->log, "ioctl(%d, DP_POLL) returned invalid " + "fd:%d ev:%04Xd rev:%04uXi", + ds->devpoll, fd, pfd->events, events); + + nxt_devpoll_remove(thr, ds, fd); + continue; + } + + nxt_log_debug(ev->log, "devpoll: fd:%d ev:%04uXi rd:%d wr:%d", + fd, events, ev->read, ev->write); + + if (nxt_slow_path(events & (POLLERR | POLLHUP | POLLNVAL)) != 0) { + nxt_log_alert(ev->log, + "ioctl(%d, DP_POLL) error fd:%d ev:%04Xd rev:%04uXi", + ds->devpoll, fd, pfd->events, events); + + nxt_thread_work_queue_add(thr, &thr->work_queue.main, + ev->error_handler, ev, ev->data, ev->log); + continue; + } + + if (events & POLLIN) { + ev->read_ready = 1; + + if (ev->read != NXT_EVENT_BLOCKED) { + + if (ev->read == NXT_EVENT_ONESHOT) { + nxt_devpoll_disable_read(event_set, ev); + } + + nxt_thread_work_queue_add(thr, ev->read_work_queue, + ev->read_handler, + ev, ev->data, ev->log); + } + } + + if (events & POLLOUT) { + ev->write_ready = 1; + + if (ev->write != NXT_EVENT_BLOCKED) { + + if (ev->write == NXT_EVENT_ONESHOT) { + nxt_devpoll_disable_write(event_set, ev); + } + + nxt_thread_work_queue_add(thr, ev->write_work_queue, + ev->write_handler, + ev, ev->data, ev->log); + } + } + } +} |