Introduce kqueue() and kevent(), a kernel event notification facility.

1 files changed, 109 insertions, 0 deletions

diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index e4433be..76495e1 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -40,8 +40,10 @@
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/domain.h>
+#include <sys/file.h>			/* for struct knote */
 #include <sys/kernel.h>
 #include <sys/malloc.h>
+#include <sys/event.h>
 #include <sys/poll.h>
 #include <sys/proc.h>
 #include <sys/protosw.h>
@@ -55,6 +57,22 @@
 
 #include <machine/limits.h>
 
+static int 	filt_sorattach(struct knote *kn);
+static void 	filt_sordetach(struct knote *kn);
+static int 	filt_soread(struct knote *kn, long hint);
+static int 	filt_sowattach(struct knote *kn);
+static void 	filt_sowdetach(struct knote *kn);
+static int	filt_sowrite(struct knote *kn, long hint);
+static int	filt_solisten(struct knote *kn, long hint);
+
+static struct filterops solisten_filtops = 
+	{ 1, filt_sorattach, filt_sordetach, filt_solisten };
+
+struct filterops so_rwfiltops[] = {
+	{ 1, filt_sorattach, filt_sordetach, filt_soread },
+	{ 1, filt_sowattach, filt_sowdetach, filt_sowrite },
+};
+
 struct	vm_zone *socket_zone;
 so_gen_t	so_gencnt;	/* generation count for sockets */
 
@@ -1388,3 +1406,94 @@ sopoll(struct socket *so, int events, struct ucred *cred, struct proc *p)
 	splx(s);
 	return (revents);
 }
+
+static int
+filt_sorattach(struct knote *kn)
+{
+	struct socket *so = (struct socket *)kn->kn_fp->f_data;
+	int s = splnet();
+
+	if (so->so_options & SO_ACCEPTCONN)
+		kn->kn_fop = &solisten_filtops;
+	SLIST_INSERT_HEAD(&so->so_rcv.sb_sel.si_note, kn, kn_selnext);
+	so->so_rcv.sb_flags |= SB_KNOTE;
+	splx(s);
+	return (0);
+}
+
+static void
+filt_sordetach(struct knote *kn)
+{
+	struct socket *so = (struct socket *)kn->kn_fp->f_data;
+	int s = splnet();
+
+	SLIST_REMOVE(&so->so_rcv.sb_sel.si_note, kn, knote, kn_selnext);
+	if (SLIST_EMPTY(&so->so_rcv.sb_sel.si_note))
+		so->so_rcv.sb_flags &= ~SB_KNOTE;
+	splx(s);
+}
+
+/*ARGSUSED*/
+static int
+filt_soread(struct knote *kn, long hint)
+{
+	struct socket *so = (struct socket *)kn->kn_fp->f_data;
+
+	kn->kn_data = so->so_rcv.sb_cc;
+	if (so->so_state & SS_CANTRCVMORE) {
+		kn->kn_flags |= EV_EOF; 
+		return (1);
+	}
+	return (kn->kn_data > 0);
+}
+
+static int
+filt_sowattach(struct knote *kn)
+{
+	struct socket *so = (struct socket *)kn->kn_fp->f_data;
+	int s = splnet();
+
+	SLIST_INSERT_HEAD(&so->so_snd.sb_sel.si_note, kn, kn_selnext);
+	so->so_snd.sb_flags |= SB_KNOTE;
+	splx(s);
+	return (0);
+}
+
+static void
+filt_sowdetach(struct knote *kn)
+{
+	struct socket *so = (struct socket *)kn->kn_fp->f_data;
+	int s = splnet();
+
+	SLIST_REMOVE(&so->so_snd.sb_sel.si_note, kn, knote, kn_selnext);
+	if (SLIST_EMPTY(&so->so_snd.sb_sel.si_note))
+		so->so_snd.sb_flags &= ~SB_KNOTE;
+	splx(s);
+}
+
+/*ARGSUSED*/
+static int
+filt_sowrite(struct knote *kn, long hint)
+{
+	struct socket *so = (struct socket *)kn->kn_fp->f_data;
+
+	kn->kn_data = sbspace(&so->so_snd);
+	if (so->so_state & SS_CANTSENDMORE) {
+		kn->kn_flags |= EV_EOF; 
+		return (1);
+	}
+	if (((so->so_state & SS_ISCONNECTED) == 0) &&
+	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
+		return (0);
+	return (kn->kn_data >= so->so_snd.sb_lowat);
+}
+
+/*ARGSUSED*/
+static int
+filt_solisten(struct knote *kn, long hint)
+{
+	struct socket *so = (struct socket *)kn->kn_fp->f_data;
+
+	kn->kn_data = so->so_qlen - so->so_incqlen;
+	return (! TAILQ_EMPTY(&so->so_comp));
+}