events_standard.c

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			 */
			if (!(fde->additional_flags & EPOLL_ADDITIONAL_FD_FLAG_REPORT_ERROR)) {
				epoll_del_event(std_ev, fde);
				continue;
			}
			flags |= EVENT_FD_READ;
		}
		if (events[i].events & EPOLLIN) flags |= EVENT_FD_READ;
		if (events[i].events & EPOLLOUT) flags |= EVENT_FD_WRITE;
		if (flags) {
			fde->handler(std_ev->ev, fde, flags, fde->private_data);
			if (destruction_count != std_ev->destruction_count) {
				break;
			}
		}
	}

	return 0;
}
#else
#define epoll_init_ctx(std_ev) 
#define epoll_add_event(std_ev,fde)
#define epoll_del_event(std_ev,fde)
#define epoll_change_event(std_ev,fde)
#define epoll_event_loop(std_ev,tvalp) (-1)
#define epoll_check_reopen(std_ev)
#endif

/*
  create a std_event_context structure.
*/
static int std_event_context_init(struct event_context *ev)
{
	struct std_event_context *std_ev;

	std_ev = talloc_zero(ev, struct std_event_context);
	if (!std_ev) return -1;
	std_ev->ev = ev;
	std_ev->epoll_fd = -1;

	epoll_init_ctx(std_ev);

	ev->additional_data = std_ev;
	return 0;
}

/*
  recalculate the maxfd
*/
static void calc_maxfd(struct std_event_context *std_ev)
{
	struct fd_event *fde;

	std_ev->maxfd = 0;
	for (fde = std_ev->fd_events; fde; fde = fde->next) {
		if (fde->fd > std_ev->maxfd) {
			std_ev->maxfd = fde->fd;
		}
	}
}


/* to mark the ev->maxfd invalid
 * this means we need to recalculate it
 */
#define EVENT_INVALID_MAXFD (-1)

/*
  destroy an fd_event
*/
static int std_event_fd_destructor(struct fd_event *fde)
{
	struct event_context *ev = fde->event_ctx;
	struct std_event_context *std_ev = talloc_get_type(ev->additional_data,
							   struct std_event_context);

	epoll_check_reopen(std_ev);

	if (std_ev->maxfd == fde->fd) {
		std_ev->maxfd = EVENT_INVALID_MAXFD;
	}

	DLIST_REMOVE(std_ev->fd_events, fde);
	std_ev->destruction_count++;

	epoll_del_event(std_ev, fde);

	if (fde->flags & EVENT_FD_AUTOCLOSE) {
		close(fde->fd);
		fde->fd = -1;
	}

	return 0;
}

/*
  add a fd based event
  return NULL on failure (memory allocation error)
*/
static struct fd_event *std_event_add_fd(struct event_context *ev, TALLOC_CTX *mem_ctx,
					 int fd, uint16_t flags,
					 event_fd_handler_t handler,
					 void *private_data)
{
	struct std_event_context *std_ev = talloc_get_type(ev->additional_data,
							   struct std_event_context);
	struct fd_event *fde;

	epoll_check_reopen(std_ev);

	fde = talloc(mem_ctx?mem_ctx:ev, struct fd_event);
	if (!fde) return NULL;

	fde->event_ctx		= ev;
	fde->fd			= fd;
	fde->flags		= flags;
	fde->handler		= handler;
	fde->private_data	= private_data;
	fde->additional_flags	= 0;
	fde->additional_data	= NULL;

	DLIST_ADD(std_ev->fd_events, fde);
	if ((std_ev->maxfd != EVENT_INVALID_MAXFD)
	    && (fde->fd > std_ev->maxfd)) {
		std_ev->maxfd = fde->fd;
	}
	talloc_set_destructor(fde, std_event_fd_destructor);

	epoll_add_event(std_ev, fde);

	return fde;
}


/*
  return the fd event flags
*/
static uint16_t std_event_get_fd_flags(struct fd_event *fde)
{
	return fde->flags;
}

/*
  set the fd event flags
*/
static void std_event_set_fd_flags(struct fd_event *fde, uint16_t flags)
{
	struct event_context *ev;
	struct std_event_context *std_ev;

	if (fde->flags == flags) return;

	ev = fde->event_ctx;
	std_ev = talloc_get_type(ev->additional_data, struct std_event_context);

	fde->flags = flags;

	epoll_check_reopen(std_ev);

	epoll_change_event(std_ev, fde);
}

/*
  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 fd_event *fde;
	int selrtn;
	uint32_t destruction_count = ++std_ev->destruction_count;

	/* 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->fd_events; fde; fde = fde->next) {
		if (fde->flags & EVENT_FD_READ) {
			FD_SET(fde->fd, &r_fds);
		}
		if (fde->flags & EVENT_FD_WRITE) {
			FD_SET(fde->fd, &w_fds);
		}
	}

	if (std_ev->ev->num_signal_handlers && 
	    common_event_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->num_signal_handlers) {
		common_event_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. */
		DEBUG(0,("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 */
		common_event_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->fd_events; fde; fde = fde->next) {
			uint16_t flags = 0;

			if (FD_ISSET(fde->fd, &r_fds)) flags |= EVENT_FD_READ;
			if (FD_ISSET(fde->fd, &w_fds)) flags |= EVENT_FD_WRITE;
			if (flags) {
				fde->handler(std_ev->ev, fde, flags, fde->private_data);
				if (destruction_count != std_ev->destruction_count) {
					break;
				}
			}
		}
	}

	return 0;
}		

/*
  do a single event loop using the events defined in ev 
*/
static int std_event_loop_once(struct event_context *ev)
{
	struct std_event_context *std_ev = talloc_get_type(ev->additional_data,
		 					   struct std_event_context);
	struct timeval tval;

	tval = common_event_loop_timer_delay(ev);
	if (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);
}

/*
  return on failure or (with 0) if all fd events are removed
*/
static int std_event_loop_wait(struct event_context *ev)
{
	struct std_event_context *std_ev = talloc_get_type(ev->additional_data,
							   struct std_event_context);
	std_ev->exit_code = 0;

	while (std_ev->fd_events && std_ev->exit_code == 0) {
		if (std_event_loop_once(ev) != 0) {
			break;
		}
	}

	return std_ev->exit_code;
}

static const struct event_ops std_event_ops = {
	.context_init	= std_event_context_init,
	.add_fd		= std_event_add_fd,
	.get_fd_flags	= std_event_get_fd_flags,
	.set_fd_flags	= std_event_set_fd_flags,
	.add_timed	= common_event_add_timed,
	.add_signal	= common_event_add_signal,
	.loop_once	= std_event_loop_once,
	.loop_wait	= std_event_loop_wait,
};


bool events_standard_init(void)
{
	return event_register_backend("standard", &std_event_ops);
}

#if _SAMBA_BUILD_
_PUBLIC_ NTSTATUS s4_events_standard_init(void)
{
	if (!events_standard_init()) {
		return NT_STATUS_INTERNAL_ERROR;
	}
	return NT_STATUS_OK;
}
#endif