+++ /dev/null
-/*
- Unix SMB/CIFS implementation.
- main select loop and event handling
- Copyright (C) Andrew Tridgell 2003-2005
- Copyright (C) Stefan Metzmacher 2005-2009
-
- ** NOTE! The following LGPL license applies to the tevent
- ** library. This does NOT imply that all of Samba is released
- ** under the LGPL
-
- This library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 3 of the License, or (at your option) any later version.
-
- This library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with this library; if not, see <http://www.gnu.org/licenses/>.
-*/
-
-#include "replace.h"
-#include "system/filesys.h"
-#include "system/select.h"
-#include "tevent.h"
-#include "tevent_util.h"
-#include "tevent_internal.h"
-
-struct select_event_context {
- /* a pointer back to the generic event_context */
- struct tevent_context *ev;
-
- /* the maximum file descriptor number in fd_events */
- int maxfd;
-};
-
-/*
- create a select_event_context structure.
-*/
-static int select_event_context_init(struct tevent_context *ev)
-{
- struct select_event_context *select_ev;
-
- /*
- * We might be called during tevent_re_initialise()
- * which means we need to free our old additional_data.
- */
- TALLOC_FREE(ev->additional_data);
-
- select_ev = talloc_zero(ev, struct select_event_context);
- if (!select_ev) return -1;
- select_ev->ev = ev;
-
- ev->additional_data = select_ev;
- return 0;
-}
-
-/*
- recalculate the maxfd
-*/
-static void calc_maxfd(struct select_event_context *select_ev)
-{
- struct tevent_fd *fde;
-
- select_ev->maxfd = 0;
- for (fde = select_ev->ev->fd_events; fde; fde = fde->next) {
- if (fde->fd > select_ev->maxfd) {
- select_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 select_event_fd_destructor(struct tevent_fd *fde)
-{
- struct tevent_context *ev = fde->event_ctx;
- struct select_event_context *select_ev = NULL;
-
- if (ev) {
- select_ev = talloc_get_type_abort(ev->additional_data,
- struct select_event_context);
-
- if (select_ev->maxfd == fde->fd) {
- select_ev->maxfd = EVENT_INVALID_MAXFD;
- }
- }
-
- return tevent_common_fd_destructor(fde);
-}
-
-/*
- add a fd based event
- return NULL on failure (memory allocation error)
-*/
-static struct tevent_fd *select_event_add_fd(struct tevent_context *ev, TALLOC_CTX *mem_ctx,
- int fd, uint16_t flags,
- tevent_fd_handler_t handler,
- void *private_data,
- const char *handler_name,
- const char *location)
-{
- struct select_event_context *select_ev =
- talloc_get_type_abort(ev->additional_data,
- struct select_event_context);
- struct tevent_fd *fde;
-
- if (fd < 0 || fd >= FD_SETSIZE) {
- errno = EBADF;
- return NULL;
- }
-
- fde = tevent_common_add_fd(ev, mem_ctx, fd, flags,
- handler, private_data,
- handler_name, location);
- if (!fde) return NULL;
-
- if ((select_ev->maxfd != EVENT_INVALID_MAXFD)
- && (fde->fd > select_ev->maxfd)) {
- select_ev->maxfd = fde->fd;
- }
- talloc_set_destructor(fde, select_event_fd_destructor);
-
- return fde;
-}
-
-/*
- event loop handling using select()
-*/
-static int select_event_loop_select(struct select_event_context *select_ev, struct timeval *tvalp)
-{
- fd_set r_fds, w_fds;
- struct tevent_fd *fde;
- int selrtn;
- int select_errno;
-
- /* we maybe need to recalculate the maxfd */
- if (select_ev->maxfd == EVENT_INVALID_MAXFD) {
- calc_maxfd(select_ev);
- }
-
- FD_ZERO(&r_fds);
- FD_ZERO(&w_fds);
-
- /* setup any fd events */
- for (fde = select_ev->ev->fd_events; fde; fde = fde->next) {
- if (fde->fd < 0 || fde->fd >= FD_SETSIZE) {
- tevent_debug(select_ev->ev, TEVENT_DEBUG_FATAL,
- "ERROR: EBADF fd[%d] >= %d "
- "select_event_loop_once\n",
- fde->fd, FD_SETSIZE);
- errno = 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 (select_ev->ev->signal_events &&
- tevent_common_check_signal(select_ev->ev)) {
- return 0;
- }
-
- tevent_trace_point_callback(select_ev->ev, TEVENT_TRACE_BEFORE_WAIT);
- selrtn = select(select_ev->maxfd+1, &r_fds, &w_fds, NULL, tvalp);
- select_errno = errno;
- tevent_trace_point_callback(select_ev->ev, TEVENT_TRACE_AFTER_WAIT);
-
- if (selrtn == -1 && select_errno == EINTR &&
- select_ev->ev->signal_events) {
- tevent_common_check_signal(select_ev->ev);
- return 0;
- }
-
- if (selrtn == -1 && select_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(select_ev->ev, TEVENT_DEBUG_FATAL,
- "ERROR: EBADF on select_event_loop_once\n");
- errno = select_errno;
- return -1;
- }
-
- if (selrtn == 0 && tvalp) {
- /* we don't care about a possible delay here */
- tevent_common_loop_timer_delay(select_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 = select_ev->ev->fd_events; fde; fde = fde->next) {
- uint16_t flags = 0;
-
- if (FD_ISSET(fde->fd, &r_fds) && (fde->flags & TEVENT_FD_READ)) {
- flags |= TEVENT_FD_READ;
- }
- if (FD_ISSET(fde->fd, &w_fds) && (fde->flags & TEVENT_FD_WRITE)) {
- flags |= TEVENT_FD_WRITE;
- }
- if (flags) {
- DLIST_DEMOTE(select_ev->ev->fd_events, fde);
- fde->handler(select_ev->ev, fde, flags, fde->private_data);
- break;
- }
- }
- }
-
- return 0;
-}
-
-/*
- do a single event loop using the events defined in ev
-*/
-static int select_event_loop_once(struct tevent_context *ev, const char *location)
-{
- struct select_event_context *select_ev =
- talloc_get_type_abort(ev->additional_data,
- struct select_event_context);
- struct timeval tval;
-
- if (ev->signal_events &&
- tevent_common_check_signal(ev)) {
- return 0;
- }
-
- if (ev->threaded_contexts != NULL) {
- tevent_common_threaded_activate_immediate(ev);
- }
-
- 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;
- }
-
- return select_event_loop_select(select_ev, &tval);
-}
-
-static const struct tevent_ops select_event_ops = {
- .context_init = select_event_context_init,
- .add_fd = select_event_add_fd,
- .set_fd_close_fn = tevent_common_fd_set_close_fn,
- .get_fd_flags = tevent_common_fd_get_flags,
- .set_fd_flags = tevent_common_fd_set_flags,
- .add_timer = tevent_common_add_timer_v2,
- .schedule_immediate = tevent_common_schedule_immediate,
- .add_signal = tevent_common_add_signal,
- .loop_once = select_event_loop_once,
- .loop_wait = tevent_common_loop_wait,
-};
-
-_PRIVATE_ bool tevent_select_init(void)
-{
- return tevent_register_backend("select", &select_event_ops);
-}
git.samba.org / samba.git / commitdiff