/*
* 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);
}
}
}
}
