/*
do a single event loop using the events defined in ev
*/
static int std_event_loop_once(struct tevent_context *ev, const char *location)
{
struct std_event_context *std_ev = talloc_get_type(ev->additional_data,
struct std_event_context);
struct timeval tval;
if (ev->signal_events &&
tevent_common_check_signal(ev)) {
return 0;
}
if (ev->immediate_events &&
tevent_common_loop_immediate(ev)) {
return 0;
}
tval = tevent_common_loop_timer_delay(ev);
if (tevent_timeval_is_zero(&tval)) {
return 0;
}
epoll_check_reopen(std_ev);
if (epoll_event_loop(std_ev, &tval) == 0) {
return 0;
}
return std_event_loop_select(std_ev, &tval);
}
/*
event loop handling using poll()
*/
static int poll_event_loop_poll(struct tevent_context *ev,
struct timeval *tvalp)
{
struct poll_event_context *poll_ev = talloc_get_type_abort(
ev->additional_data, struct poll_event_context);
int pollrtn;
int timeout = -1;
int poll_errno;
struct tevent_fd *fde = NULL;
unsigned i;
if (ev->signal_events && tevent_common_check_signal(ev)) {
return 0;
}
if (tvalp != NULL) {
timeout = tvalp->tv_sec * 1000;
timeout += (tvalp->tv_usec + 999) / 1000;
}
poll_event_drain_signal_fd(poll_ev);
if (!poll_event_setup_fresh(ev, poll_ev)) {
return -1;
}
tevent_trace_point_callback(poll_ev->ev, TEVENT_TRACE_BEFORE_WAIT);
pollrtn = poll(poll_ev->fds, poll_ev->num_fds, timeout);
poll_errno = errno;
tevent_trace_point_callback(poll_ev->ev, TEVENT_TRACE_AFTER_WAIT);
if (pollrtn == -1 && poll_errno == EINTR && ev->signal_events) {
tevent_common_check_signal(ev);
return 0;
}
if (pollrtn == 0 && tvalp) {
/* we don't care about a possible delay here */
tevent_common_loop_timer_delay(ev);
return 0;
}
if (pollrtn <= 0) {
/*
* No fd's ready
*/
return 0;
}
/* at least one file descriptor is ready - check
which ones and call the handler, being careful to allow
the handler to remove itself when called */
for (fde = ev->fd_events; fde; fde = fde->next) {
unsigned idx = fde->additional_flags;
struct pollfd *pfd;
uint16_t flags = 0;
if (idx == UINT64_MAX) {
continue;
}
pfd = &poll_ev->fds[idx];
if (pfd->revents & POLLNVAL) {
/*
* the socket is dead! this should never
* happen as the socket should have first been
* made readable and that should have removed
* the event, so this must be a bug.
*
* We ignore it here to match the epoll
* behavior.
*/
tevent_debug(ev, TEVENT_DEBUG_ERROR,
"POLLNVAL on fde[%p] fd[%d] - disabling\n",
fde, pfd->fd);
poll_ev->fdes[idx] = NULL;
poll_ev->deleted = true;
DLIST_REMOVE(ev->fd_events, fde);
fde->event_ctx = NULL;
continue;
}
if (pfd->revents & (POLLHUP|POLLERR)) {
/* If we only wait for TEVENT_FD_WRITE, we
should not tell the event handler about it,
and remove the writable flag, as we only
report errors when waiting for read events
to match the select behavior. */
if (!(fde->flags & TEVENT_FD_READ)) {
TEVENT_FD_NOT_WRITEABLE(fde);
continue;
}
flags |= TEVENT_FD_READ;
}
if (pfd->revents & POLLIN) {
flags |= TEVENT_FD_READ;
}
if (pfd->revents & POLLOUT) {
flags |= TEVENT_FD_WRITE;
}
/*
* Note that fde->flags could be changed when using
* the poll_mt backend together with threads,
* that why we need to check pfd->revents and fde->flags
*/
flags &= fde->flags;
if (flags != 0) {
DLIST_DEMOTE(ev->fd_events, fde, struct tevent_fd);
fde->handler(ev, fde, flags, fde->private_data);
return 0;
}
}
/*
event loop handling using select()
*/
static int std_event_loop_select(struct std_event_context *std_ev, struct timeval *tvalp)
{
fd_set r_fds, w_fds;
struct tevent_fd *fde;
int selrtn;
/* we maybe need to recalculate the maxfd */
if (std_ev->maxfd == EVENT_INVALID_MAXFD) {
calc_maxfd(std_ev);
}
FD_ZERO(&r_fds);
FD_ZERO(&w_fds);
/* setup any fd events */
for (fde = std_ev->ev->fd_events; fde; fde = fde->next) {
if (fde->fd < 0 || fde->fd >= FD_SETSIZE) {
std_ev->exit_code = EBADF;
return -1;
}
if (fde->flags & TEVENT_FD_READ) {
FD_SET(fde->fd, &r_fds);
}
if (fde->flags & TEVENT_FD_WRITE) {
FD_SET(fde->fd, &w_fds);
}
}
if (std_ev->ev->signal_events &&
tevent_common_check_signal(std_ev->ev)) {
return 0;
}
selrtn = select(std_ev->maxfd+1, &r_fds, &w_fds, NULL, tvalp);
if (selrtn == -1 && errno == EINTR &&
std_ev->ev->signal_events) {
tevent_common_check_signal(std_ev->ev);
return 0;
}
if (selrtn == -1 && errno == EBADF) {
/* the socket is dead! this should never
happen as the socket should have first been
made readable and that should have removed
the event, so this must be a bug. This is a
fatal error. */
tevent_debug(std_ev->ev, TEVENT_DEBUG_FATAL,
"ERROR: EBADF on std_event_loop_once\n");
std_ev->exit_code = EBADF;
return -1;
}
if (selrtn == 0 && tvalp) {
/* we don't care about a possible delay here */
tevent_common_loop_timer_delay(std_ev->ev);
return 0;
}
if (selrtn > 0) {
/* at least one file descriptor is ready - check
which ones and call the handler, being careful to allow
the handler to remove itself when called */
for (fde = std_ev->ev->fd_events; fde; fde = fde->next) {
uint16_t flags = 0;
if (FD_ISSET(fde->fd, &r_fds)) flags |= TEVENT_FD_READ;
if (FD_ISSET(fde->fd, &w_fds)) flags |= TEVENT_FD_WRITE;
if (flags) {
fde->handler(std_ev->ev, fde, flags, fde->private_data);
break;
}
}
}
return 0;
}
/*
event loop handling using epoll
*/
static int epoll_event_loop(struct std_event_context *std_ev, struct timeval *tvalp)
{
int ret, i;
#define MAXEVENTS 1
struct epoll_event events[MAXEVENTS];
int timeout = -1;
if (std_ev->epoll_fd == -1) return -1;
if (tvalp) {
/* it's better to trigger timed events a bit later than to early */
timeout = ((tvalp->tv_usec+999) / 1000) + (tvalp->tv_sec*1000);
}
if (std_ev->ev->signal_events &&
tevent_common_check_signal(std_ev->ev)) {
return 0;
}
ret = epoll_wait(std_ev->epoll_fd, events, MAXEVENTS, timeout);
if (ret == -1 && errno == EINTR && std_ev->ev->signal_events) {
if (tevent_common_check_signal(std_ev->ev)) {
return 0;
}
}
if (ret == -1 && errno != EINTR) {
epoll_fallback_to_select(std_ev, "epoll_wait() failed");
return -1;
}
if (ret == 0 && tvalp) {
/* we don't care about a possible delay here */
tevent_common_loop_timer_delay(std_ev->ev);
return 0;
}
for (i=0;i<ret;i++) {
struct tevent_fd *fde = talloc_get_type(events[i].data.ptr,
struct tevent_fd);
uint16_t flags = 0;
if (fde == NULL) {
epoll_fallback_to_select(std_ev, "epoll_wait() gave bad data");
return -1;
}
if (events[i].events & (EPOLLHUP|EPOLLERR)) {
fde->additional_flags |= EPOLL_ADDITIONAL_FD_FLAG_GOT_ERROR;
/*
* if we only wait for TEVENT_FD_WRITE, we should not tell the
* event handler about it, and remove the epoll_event,
* as we only report errors when waiting for read events,
* to match the select() behavior
*/
if (!(fde->additional_flags & EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR)) {
epoll_del_event(std_ev, fde);
continue;
}
flags |= TEVENT_FD_READ;
}
if (events[i].events & EPOLLIN) flags |= TEVENT_FD_READ;
if (events[i].events & EPOLLOUT) flags |= TEVENT_FD_WRITE;
if (flags) {
fde->handler(std_ev->ev, fde, flags, fde->private_data);
break;
}
}
return 0;
}
