[src/trunk]: src/sys Add a new function, sleepq_transfer(), that moves an lwp...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/397c12f38724
branches:  trunk
changeset: 971904:397c12f38724
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Fri May 08 03:26:51 2020 +0000

description:
Add a new function, sleepq_transfer(), that moves an lwp from one
sleepq to another.

diffstat:

 sys/kern/kern_sleepq.c |  36 ++++++++++++++++++++++++++++++++++--
 sys/sys/sleepq.h       |   6 ++++--
 2 files changed, 38 insertions(+), 4 deletions(-)

diffs (77 lines):

diff -r 70505bc2426d -r 397c12f38724 sys/kern/kern_sleepq.c
--- a/sys/kern/kern_sleepq.c    Fri May 08 00:54:44 2020 +0000
+++ b/sys/kern/kern_sleepq.c    Fri May 08 03:26:51 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_sleepq.c,v 1.66 2020/04/19 20:35:29 ad Exp $      */
+/*     $NetBSD: kern_sleepq.c,v 1.67 2020/05/08 03:26:51 thorpej Exp $ */
 
 /*-
  * Copyright (c) 2006, 2007, 2008, 2009, 2019, 2020 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_sleepq.c,v 1.66 2020/04/19 20:35:29 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sleepq.c,v 1.67 2020/05/08 03:26:51 thorpej Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -237,6 +237,38 @@
 }
 
 /*
+ * sleepq_transfer:
+ *
+ *     Move an LWP from one sleep queue to another.  Both sleep queues
+ *     must already be locked.
+ *
+ *     The LWP will be updated with the new sleepq, wchan, wmesg,
+ *     sobj, and mutex.  The interruptible flag will also be updated.
+ */
+void
+sleepq_transfer(lwp_t *l, sleepq_t *from_sq, sleepq_t *sq, wchan_t wchan,
+    const char *wmesg, syncobj_t *sobj, kmutex_t *mp, bool catch_p)
+{
+
+       KASSERT(l->l_sleepq == from_sq);
+
+       LIST_REMOVE(l, l_sleepchain);
+       l->l_syncobj = sobj;
+       l->l_wchan = wchan;
+       l->l_sleepq = sq;
+       l->l_wmesg = wmesg;
+
+       if (catch_p)
+               l->l_flag |= LW_SINTR;
+       else
+               l->l_flag &= ~LW_SINTR;
+
+       lwp_setlock(l, mp);
+
+       sleepq_insert(sq, l, sobj);
+}
+
+/*
  * sleepq_block:
  *
  *     After any intermediate step such as releasing an interlock, switch.
diff -r 70505bc2426d -r 397c12f38724 sys/sys/sleepq.h
--- a/sys/sys/sleepq.h  Fri May 08 00:54:44 2020 +0000
+++ b/sys/sys/sleepq.h  Fri May 08 03:26:51 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sleepq.h,v 1.29 2020/04/19 20:35:29 ad Exp $   */
+/*     $NetBSD: sleepq.h,v 1.30 2020/05/08 03:26:51 thorpej Exp $      */
 
 /*-
  * Copyright (c) 2002, 2006, 2007, 2008, 2009, 2019, 2020
@@ -61,7 +61,9 @@
 void   sleepq_init(sleepq_t *);
 void   sleepq_remove(sleepq_t *, lwp_t *);
 void   sleepq_enqueue(sleepq_t *, wchan_t, const char *, struct syncobj *,
-    bool);
+           bool);
+void   sleepq_transfer(lwp_t *, sleepq_t *, sleepq_t *, wchan_t, const char *,
+           struct syncobj *, kmutex_t *, bool);
 void   sleepq_unsleep(lwp_t *, bool);
 void   sleepq_timeout(void *);
 void   sleepq_wake(sleepq_t *, wchan_t, u_int, kmutex_t *);