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);
55 struct osmo_fd *entry;
56 llist_for_each_entry(entry, &osmo_fds, list) {
58 fprintf(stderr, "Adding a osmo_fd that is already in the list.\n");
64 llist_add_tail(&fd->list, &osmo_fds);
69 void osmo_fd_unregister(struct osmo_fd *fd)
75 int osmo_select_main(int polling)
77 struct osmo_fd *ufd, *tmp;
78 fd_set readset, writeset, exceptset;
80 struct timeval no_time = {0, 0};
86 /* prepare read and write fdsets */
87 llist_for_each_entry(ufd, &osmo_fds, list) {
88 if (ufd->when & BSC_FD_READ)
89 FD_SET(ufd->fd, &readset);
91 if (ufd->when & BSC_FD_WRITE)
92 FD_SET(ufd->fd, &writeset);
94 if (ufd->when & BSC_FD_EXCEPT)
95 FD_SET(ufd->fd, &exceptset);
101 osmo_timers_prepare();
102 rc = select(maxfd+1, &readset, &writeset, &exceptset, polling ? &no_time : osmo_timers_nearest());
107 osmo_timers_update();
109 /* call registered callback functions */
111 unregistered_count = 0;
112 llist_for_each_entry_safe(ufd, tmp, &osmo_fds, list) {
115 if (FD_ISSET(ufd->fd, &readset)) {
116 flags |= BSC_FD_READ;
117 FD_CLR(ufd->fd, &readset);
120 if (FD_ISSET(ufd->fd, &writeset)) {
121 flags |= BSC_FD_WRITE;
122 FD_CLR(ufd->fd, &writeset);
125 if (FD_ISSET(ufd->fd, &exceptset)) {
126 flags |= BSC_FD_EXCEPT;
127 FD_CLR(ufd->fd, &exceptset);
134 /* ugly, ugly hack. If more than one filedescriptors were
135 * unregistered, they might have been consecutive and
136 * llist_for_each_entry_safe() is no longer safe */
137 /* this seems to happen with the last element of the list as well */
138 if (unregistered_count >= 1)
144 #endif /* _HAVE_SYS_SELECT_H */