1 /* select filedescriptor handling, taken from:
2 * userspace logging daemon for the iptables ULOG target
3 * of the linux 2.4 netfilter subsystem.
5 * (C) 2000-2009 by Harald Welte <laforge@gnumonks.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include <osmocom/core/select.h>
26 #include <osmocom/core/linuxlist.h>
27 #include <osmocom/core/timer.h>
29 #include "../config.h"
31 #ifdef HAVE_SYS_SELECT_H
34 static LLIST_HEAD(osmo_fds);
35 static int unregistered_count;
37 int osmo_fd_register(struct osmo_fd *fd)
41 /* make FD nonblocking */
42 flags = fcntl(fd->fd, F_GETFL);
46 flags = fcntl(fd->fd, F_SETFL, flags);
50 /* set close-on-exec flag */
51 flags = fcntl(fd->fd, F_GETFD);
55 flags = fcntl(fd->fd, F_SETFD, flags);
64 struct osmo_fd *entry;
65 llist_for_each_entry(entry, &osmo_fds, list) {
67 fprintf(stderr, "Adding a osmo_fd that is already in the list.\n");
73 llist_add_tail(&fd->list, &osmo_fds);
78 void osmo_fd_unregister(struct osmo_fd *fd)
84 int osmo_select_main(int polling)
86 struct osmo_fd *ufd, *tmp;
87 fd_set readset, writeset, exceptset;
89 struct timeval no_time = {0, 0};
95 /* prepare read and write fdsets */
96 llist_for_each_entry(ufd, &osmo_fds, list) {
97 if (ufd->when & BSC_FD_READ)
98 FD_SET(ufd->fd, &readset);
100 if (ufd->when & BSC_FD_WRITE)
101 FD_SET(ufd->fd, &writeset);
103 if (ufd->when & BSC_FD_EXCEPT)
104 FD_SET(ufd->fd, &exceptset);
110 osmo_timers_prepare();
111 rc = select(maxfd+1, &readset, &writeset, &exceptset, polling ? &no_time : osmo_timers_nearest());
116 osmo_timers_update();
118 /* call registered callback functions */
120 unregistered_count = 0;
121 llist_for_each_entry_safe(ufd, tmp, &osmo_fds, list) {
124 if (FD_ISSET(ufd->fd, &readset)) {
125 flags |= BSC_FD_READ;
126 FD_CLR(ufd->fd, &readset);
129 if (FD_ISSET(ufd->fd, &writeset)) {
130 flags |= BSC_FD_WRITE;
131 FD_CLR(ufd->fd, &writeset);
134 if (FD_ISSET(ufd->fd, &exceptset)) {
135 flags |= BSC_FD_EXCEPT;
136 FD_CLR(ufd->fd, &exceptset);
143 /* ugly, ugly hack. If more than one filedescriptors were
144 * unregistered, they might have been consecutive and
145 * llist_for_each_entry_safe() is no longer safe */
146 /* this seems to happen with the last element of the list as well */
147 if (unregistered_count >= 1)
153 #endif /* _HAVE_SYS_SELECT_H */