intial checkin of the libosmocore project

1 files changed, 128 insertions, 0 deletions

diff --git a/src/select.c b/src/select.c
new file mode 100644
index 00000000..4f5d7ed9
--- /dev/null
+++ b/src/select.c
@@ -0,0 +1,128 @@
+/* select filedescriptor handling, taken from:
+ * userspace logging daemon for the iptables ULOG target
+ * of the linux 2.4 netfilter subsystem.
+ *
+ * (C) 2000-2009 by Harald Welte <laforge@gnumonks.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 
+ *  as published by the Free Software Foundation
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <fcntl.h>
+#include <osmocore/select.h>
+#include <osmocore/linuxlist.h>
+#include <osmocore/timer.h>
+
+#ifdef HAVE_SYS_SELECT_H
+
+static int maxfd = 0;
+static LLIST_HEAD(bsc_fds);
+static int unregistered_count;
+
+int bsc_register_fd(struct bsc_fd *fd)
+{
+	int flags;
+
+	/* make FD nonblocking */
+	flags = fcntl(fd->fd, F_GETFL);
+	if (flags < 0)
+		return flags;
+	flags |= O_NONBLOCK;
+	flags = fcntl(fd->fd, F_SETFL, flags);
+	if (flags < 0)
+		return flags;
+
+	/* Register FD */
+	if (fd->fd > maxfd)
+		maxfd = fd->fd;
+
+	llist_add_tail(&fd->list, &bsc_fds);
+
+	return 0;
+}
+
+void bsc_unregister_fd(struct bsc_fd *fd)
+{
+	unregistered_count++;
+	llist_del(&fd->list);
+}
+
+int bsc_select_main(int polling)
+{
+	struct bsc_fd *ufd, *tmp;
+	fd_set readset, writeset, exceptset;
+	int work = 0, rc;
+	struct timeval no_time = {0, 0};
+
+	FD_ZERO(&readset);
+	FD_ZERO(&writeset);
+	FD_ZERO(&exceptset);
+
+	/* prepare read and write fdsets */
+	llist_for_each_entry(ufd, &bsc_fds, list) {
+		if (ufd->when & BSC_FD_READ)
+			FD_SET(ufd->fd, &readset);
+
+		if (ufd->when & BSC_FD_WRITE)
+			FD_SET(ufd->fd, &writeset);
+
+		if (ufd->when & BSC_FD_EXCEPT)
+			FD_SET(ufd->fd, &exceptset);
+	}
+
+	bsc_timer_check();
+
+	if (!polling)
+		bsc_prepare_timers();
+	rc = select(maxfd+1, &readset, &writeset, &exceptset, polling ? &no_time : bsc_nearest_timer());
+	if (rc < 0)
+		return 0;
+
+	/* fire timers */
+	bsc_update_timers();
+
+	/* call registered callback functions */
+restart:
+	unregistered_count = 0;
+	llist_for_each_entry_safe(ufd, tmp, &bsc_fds, list) {
+		int flags = 0;
+
+		if (FD_ISSET(ufd->fd, &readset)) {
+			flags |= BSC_FD_READ;
+			FD_CLR(ufd->fd, &readset);
+		}
+
+		if (FD_ISSET(ufd->fd, &writeset)) {
+			flags |= BSC_FD_WRITE;
+			FD_CLR(ufd->fd, &writeset);
+		}
+
+		if (FD_ISSET(ufd->fd, &exceptset)) {
+			flags |= BSC_FD_EXCEPT;
+			FD_CLR(ufd->fd, &exceptset);
+		}
+
+		if (flags) {
+			work = 1;
+			ufd->cb(ufd, flags);
+		}
+		/* ugly, ugly hack. If more than one filedescriptors were
+		 * unregistered, they might have been consecutive and
+		 * llist_for_each_entry_safe() is no longer safe */
+		if (unregistered_count > 1)
+			goto restart;
+	}
+	return work;
+}
+
+#endif /* _HAVE_SYS_SELECT_H */