From: Samuel J. Greear <sjg@thesjg.com>
Date: Tue, 15 Jun 2010 16:44:44 +0000 (+0000)
Subject: kernel - Add kqueue to log device (/dev/klog)
X-Git-Tag: v2.9.0~690^2~63
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/fef8f01a63adb168dd043d0e835694b0d02c59c9

kernel - Add kqueue to log device (/dev/klog)
---

diff --git a/sys/kern/subr_log.c b/sys/kern/subr_log.c
index e6b4fa57bd..d5ab5b5f2e 100644
--- a/sys/kern/subr_log.c
+++ b/sys/kern/subr_log.c
@@ -51,6 +51,7 @@
 #include <sys/signalvar.h>
 #include <sys/kernel.h>
 #include <sys/poll.h>
+#include <sys/event.h>
 #include <sys/filedesc.h>
 #include <sys/sysctl.h>
 #include <sys/thread2.h>
@@ -63,17 +64,21 @@ static	d_close_t	logclose;
 static	d_read_t	logread;
 static	d_ioctl_t	logioctl;
 static	d_poll_t	logpoll;
+static	d_kqfilter_t	logkqfilter;
 
 static	void logtimeout(void *arg);
+static	void logfiltdetach(struct knote *kn);
+static	int  logfiltread(struct knote *kn, long hint);
 
 #define CDEV_MAJOR 7
 static struct dev_ops log_ops = {
-	{ "log", CDEV_MAJOR, 0 },
+	{ "log", CDEV_MAJOR, D_KQFILTER },
 	.d_open =	logopen,
 	.d_close =	logclose,
 	.d_read =	logread,
 	.d_ioctl =	logioctl,
 	.d_poll =	logpoll,
+	.d_kqfilter =	logkqfilter
 };
 
 static struct logsoftc {
@@ -178,6 +183,55 @@ logpoll(struct dev_poll_args *ap)
 	return (0);
 }
 
+static struct filterops logread_filtops =
+	{ 1, NULL, logfiltdetach, logfiltread };
+
+static int
+logkqfilter(struct dev_kqfilter_args *ap)
+{
+	struct knote *kn = ap->a_kn;
+	struct klist *klist = &logsoftc.sc_selp.si_note;
+
+	ap->a_result = 0;
+	switch (kn->kn_filter) {
+	case EVFILT_READ:
+		kn->kn_fop = &logread_filtops;
+		break;
+	default:
+		ap->a_result = 1;
+		return (0);
+	}
+
+	crit_enter();
+	SLIST_INSERT_HEAD(klist, kn, kn_selnext);
+	crit_exit();
+
+	return (0);
+}
+
+static void
+logfiltdetach(struct knote *kn)
+{
+	struct klist *klist = &logsoftc.sc_selp.si_note;
+
+	crit_enter();
+	SLIST_REMOVE(klist, kn, knote, kn_selnext);
+	crit_exit();
+}
+
+static int
+logfiltread(struct knote *kn, long hint)
+{
+	int ret = 0;
+
+	crit_enter();
+	if (msgbufp->msg_bufr != msgbufp->msg_bufx)
+		ret = 1;
+	crit_exit();
+
+	return (ret);
+}
+
 static void
 logtimeout(void *arg)
 {