--- /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 poll_event_context {
+ /*
+ * These two arrays are maintained together.
+ */
+ struct pollfd *fds;
+ struct tevent_fd **fd_events;
+ int num_fds;
+
+ /* information for exiting from the event loop */
+ int exit_code;
+};
+
+/*
+ create a select_event_context structure.
+*/
+static int poll_event_context_init(struct tevent_context *ev)
+{
+ struct poll_event_context *poll_ev;
+
+ poll_ev = talloc_zero(ev, struct poll_event_context);
+ if (poll_ev == NULL) {
+ return -1;
+ }
+ ev->additional_data = poll_ev;
+ return 0;
+}
+
+/*
+ destroy an fd_event
+*/
+static int poll_event_fd_destructor(struct tevent_fd *fde)
+{
+ struct tevent_context *ev = fde->event_ctx;
+ struct poll_event_context *poll_ev = NULL;
+ struct tevent_fd *moved_fde;
+ int del_idx;
+
+ if (ev == NULL) {
+ goto done;
+ }
+
+ poll_ev = talloc_get_type_abort(
+ ev->additional_data, struct poll_event_context);
+
+ /*
+ * Assume a void * can carry enough bits to hold num_fds.
+ */
+ del_idx = (int)(fde->additional_data);
+
+ moved_fde = poll_ev->fd_events[poll_ev->num_fds-1];
+ poll_ev->fd_events[del_idx] = moved_fde;
+ poll_ev->fds[del_idx] = poll_ev->fds[poll_ev->num_fds-1];
+ moved_fde->additional_data = (void *)del_idx;
+
+ poll_ev->num_fds -= 1;
+done:
+ return tevent_common_fd_destructor(fde);
+}
+
+/*
+ add a fd based event
+ return NULL on failure (memory allocation error)
+*/
+static struct tevent_fd *poll_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 poll_event_context *poll_ev = talloc_get_type_abort(
+ ev->additional_data, struct poll_event_context);
+ struct pollfd *pfd;
+ struct tevent_fd *fde;
+
+ fde = tevent_common_add_fd(ev, mem_ctx, fd, flags,
+ handler, private_data,
+ handler_name, location);
+ if (fde == NULL) {
+ return NULL;
+ }
+
+ /* we allocate 16 slots to avoid a lot of reallocations */
+ if (talloc_array_length(poll_ev->fds) == poll_ev->num_fds) {
+ struct pollfd *tmp_fds;
+ struct tevent_fd **tmp_fd_events;
+ tmp_fds = talloc_realloc(
+ poll_ev, poll_ev->fds, struct pollfd,
+ poll_ev->num_fds + 16);
+ if (tmp_fds == NULL) {
+ TALLOC_FREE(fde);
+ return NULL;
+ }
+ poll_ev->fds = tmp_fds;
+
+ tmp_fd_events = talloc_realloc(
+ poll_ev, poll_ev->fd_events, struct tevent_fd *,
+ poll_ev->num_fds + 16);
+ if (tmp_fd_events == NULL) {
+ TALLOC_FREE(fde);
+ return NULL;
+ }
+ poll_ev->fd_events = tmp_fd_events;
+ }
+
+ pfd = &poll_ev->fds[poll_ev->num_fds];
+
+ pfd->fd = fd;
+
+ pfd->events = 0;
+ pfd->revents = 0;
+
+ if (flags & TEVENT_FD_READ) {
+ pfd->events |= (POLLIN|POLLHUP);
+ }
+ if (flags & TEVENT_FD_WRITE) {
+ pfd->events |= (POLLOUT);
+ }
+
+ /*
+ * Assume a void * can carry enough bits to hold num_fds.
+ */
+ fde->additional_data = (void *)poll_ev->num_fds;
+ poll_ev->fd_events[poll_ev->num_fds] = fde;
+
+ poll_ev->num_fds += 1;
+
+ talloc_set_destructor(fde, poll_event_fd_destructor);
+
+ return fde;
+}
+
+/*
+ set the fd event flags
+*/
+static void poll_event_set_fd_flags(struct tevent_fd *fde, uint16_t flags)
+{
+ struct poll_event_context *poll_ev = talloc_get_type_abort(
+ fde->event_ctx->additional_data, struct poll_event_context);
+ int idx;
+ uint16_t pollflags = 0;
+
+ if (flags & TEVENT_FD_READ) {
+ pollflags |= (POLLIN|POLLHUP);
+ }
+ if (flags & TEVENT_FD_WRITE) {
+ pollflags |= (POLLOUT);
+ }
+
+ idx = (int)(fde->additional_data);
+ poll_ev->fds[idx].events = pollflags;
+
+ fde->flags = flags;
+}
+
+/*
+ event loop handling using select()
+*/
+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);
+ struct tevent_fd *fde;
+ int pollrtn;
+ int timeout = -1;
+
+ 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;
+ }
+
+ pollrtn = poll(poll_ev->fds, poll_ev->num_fds, timeout);
+
+ if (pollrtn == -1 && errno == EINTR && ev->signal_events) {
+ tevent_common_check_signal(ev);
+ return 0;
+ }
+
+ if (pollrtn == -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(ev, TEVENT_DEBUG_FATAL,
+ "ERROR: EBADF on poll_event_loop_once\n");
+ poll_ev->exit_code = EBADF;
+ return -1;
+ }
+
+ if (pollrtn == 0 && tvalp) {
+ /* we don't care about a possible delay here */
+ tevent_common_loop_timer_delay(ev);
+ return 0;
+ }
+
+ if (pollrtn > 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) {
+ struct pollfd *pfd;
+ int pfd_idx;
+ uint16_t flags = 0;
+
+ pfd_idx = (int)(fde->additional_data);
+
+ pfd = &poll_ev->fds[pfd_idx];
+
+ if (pfd->revents & (POLLIN|POLLHUP|POLLERR)) {
+ flags |= TEVENT_FD_READ;
+ }
+ if (pfd->revents & POLLOUT) {
+ flags |= TEVENT_FD_WRITE;
+ }
+ if (flags != 0) {
+ fde->handler(ev, fde, flags,
+ fde->private_data);
+ break;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/*
+ do a single event loop using the events defined in ev
+*/
+static int poll_event_loop_once(struct tevent_context *ev,
+ const char *location)
+{
+ 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;
+ }
+
+ return poll_event_loop_poll(ev, &tval);
+}
+
+static const struct tevent_ops poll_event_ops = {
+ .context_init = poll_event_context_init,
+ .add_fd = poll_event_add_fd,
+ .set_fd_close_fn = tevent_common_fd_set_close_fn,
+ .get_fd_flags = tevent_common_fd_get_flags,
+ .set_fd_flags = poll_event_set_fd_flags,
+ .add_timer = tevent_common_add_timer,
+ .schedule_immediate = tevent_common_schedule_immediate,
+ .add_signal = tevent_common_add_signal,
+ .loop_once = poll_event_loop_once,
+ .loop_wait = tevent_common_loop_wait,
+};
+
+_PRIVATE_ bool tevent_poll_init(void)
+{
+ return tevent_register_backend("poll", &poll_event_ops);
+}
git.samba.org / samba.git / commitdiff