From 4e3a26930218d35cf08d85d517f7552adc8cb07d Mon Sep 17 00:00:00 2001
From: Owain Ainsworth <oga@cvs.openbsd.org>
Date: Wed, 28 Nov 2007 20:07:37 +0000
Subject: Add msleep. This is identical to tsleep but it takes a mutex as a
 parameter. The mutex is unlocked just before sleep and relocked after unless
 P_NORELOCK is in flags, in which case it is left unlocked.

ok art@.
---
 sys/kern/kern_synch.c | 39 ++++++++++++++++++++++++++++++++++++++-
 sys/sys/proc.h        |  4 +++-
 2 files changed, 41 insertions(+), 2 deletions(-)

(limited to 'sys')

diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index 8cd4a4285e1..209883c59b4 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_synch.c,v 1.81 2007/10/10 15:53:53 art Exp $	*/
+/*	$OpenBSD: kern_synch.c,v 1.82 2007/11/28 20:07:36 oga Exp $	*/
 /*	$NetBSD: kern_synch.c,v 1.37 1996/04/22 01:38:37 christos Exp $	*/
 
 /*
@@ -136,6 +136,43 @@ tsleep(void *ident, int priority, const char *wmesg, int timo)
 	return (error);
 }
 
+/*
+ * Same as tsleep, but if we have a mutex provided, then once we've 
+ * entered the sleep queue we drop the mutex. After sleeping we re-lock.
+ */
+int
+msleep(void *ident, struct mutex *mtx,  int priority, const char *wmesg, int timo)
+{
+	struct sleep_state sls;
+	int error, error1;
+
+	sleep_setup(&sls, ident, priority, wmesg);
+	sleep_setup_timeout(&sls, timo);
+	sleep_setup_signal(&sls, priority);
+
+	if (mtx) {
+		/* XXX - We need to make sure that the mutex doesn't
+		 * unblock splsched. This can be made a bit more 
+		 * correct when the sched_lock is a mutex.
+		 */
+		MUTEX_OLDIPL(mtx) = splsched();
+		mtx_leave(mtx);
+	}
+
+	sleep_finish(&sls, 1);
+	error1 = sleep_finish_timeout(&sls);
+	error = sleep_finish_signal(&sls);
+
+	if (mtx && (priority & PNORELOCK) == 0)
+		mtx_enter(mtx);
+
+	/* Signal errors are higher priority than timeouts. */
+	if (error == 0 && error1 != 0)
+		error = error1;
+
+	return (error);
+}
+
 void
 sleep_setup(struct sleep_state *sls, void *ident, int prio, const char *wmesg)
 {
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index a4d4a12fa62..29389bb5e6a 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.101 2007/10/10 15:53:53 art Exp $	*/
+/*	$OpenBSD: proc.h,v 1.102 2007/11/28 20:07:36 oga Exp $	*/
 /*	$NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $	*/
 
 /*-
@@ -45,6 +45,7 @@
 #include <sys/queue.h>
 #include <sys/timeout.h>		/* For struct timeout. */
 #include <sys/event.h>			/* For struct klist */
+#include <sys/mutex.h>			/* For struct mutex */
 #include <machine/atomic.h>
 
 #define curproc curcpu()->ci_curproc
@@ -454,6 +455,7 @@ int	sleep_finish_signal(struct sleep_state *);
 void	sleep_queue_init(void);
 
 int	tsleep(void *, int, const char *, int);
+int	msleep(void *, struct mutex *, int,  const char*, int);
 #define ltsleep(c, p, w, t, l) tsleep(c, p, w, t)
 
 #if defined(MULTIPROCESSOR)
-- 
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