1 /* $NetBSD: sleepq.h,v 1.36 2022/10/26 23:24:59 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2002, 2006, 2007, 2008, 2009, 2019, 2020
5 * The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Jason R. Thorpe and Andrew Doran.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #ifndef _SYS_SLEEPQ_H_
34 #define _SYS_SLEEPQ_H_
35
36 #include <sys/lwp.h>
37 #include <sys/mutex.h>
38 #include <sys/pool.h>
39 #include <sys/queue.h>
40 #include <sys/sched.h>
41 #include <sys/syncobj.h>
42 #include <sys/param.h>
43
44 /*
45 * Generic sleep queues.
46 */
47
48 typedef struct sleepq sleepq_t;
49
50 void sleepq_init(sleepq_t *);
51 void sleepq_remove(sleepq_t *, lwp_t *);
52 void sleepq_enqueue(sleepq_t *, wchan_t, const char *, struct syncobj *,
53 bool);
54 void sleepq_transfer(lwp_t *, sleepq_t *, sleepq_t *, wchan_t, const char *,
55 struct syncobj *, kmutex_t *, bool);
56 void sleepq_uncatch(lwp_t *);
57 void sleepq_unsleep(lwp_t *, bool);
58 void sleepq_timeout(void *);
59 void sleepq_wake(sleepq_t *, wchan_t, u_int, kmutex_t *);
60 int sleepq_abort(kmutex_t *, int);
61 void sleepq_changepri(lwp_t *, pri_t);
62 void sleepq_lendpri(lwp_t *, pri_t);
63 int sleepq_block(int, bool, struct syncobj *);
64
65 #ifdef _KERNEL
66
67 #include <sys/kernel.h>
68
69 typedef union {
70 kmutex_t lock;
71 uint8_t pad[COHERENCY_UNIT];
72 } sleepqlock_t;
73
74 /*
75 * Return non-zero if it is unsafe to sleep.
76 *
77 * XXX This only exists because panic() is broken.
78 */
79 static __inline bool
sleepq_dontsleep(lwp_t * l)80 sleepq_dontsleep(lwp_t *l)
81 {
82
83 return cold || (doing_shutdown && (panicstr || CURCPU_IDLE_P()));
84 }
85
86 /*
87 * Prepare to block on a sleep queue, after which any interlock can be
88 * safely released.
89 */
90 static __inline void
sleepq_enter(sleepq_t * sq,lwp_t * l,kmutex_t * mp)91 sleepq_enter(sleepq_t *sq, lwp_t *l, kmutex_t *mp)
92 {
93
94 /*
95 * Acquire the per-LWP mutex and lend it ours sleep queue lock.
96 * Once interlocked, we can release the kernel lock.
97 */
98 lwp_lock(l);
99 lwp_unlock_to(l, mp);
100 KERNEL_UNLOCK_ALL(NULL, &l->l_biglocks);
101 }
102
103 #endif
104
105 #include <sys/sleeptab.h>
106
107 #endif /* _SYS_SLEEPQ_H_ */
108