1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2010 David Xu <davidxu@freebsd.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
12 * disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <stdlib.h>
30 #include "thr_private.h"
31
32 #define HASHSHIFT 9
33 #define HASHSIZE (1 << HASHSHIFT)
34 #define SC_HASH(wchan) ((unsigned) \
35 ((((uintptr_t)(wchan) >> 3) \
36 ^ ((uintptr_t)(wchan) >> (HASHSHIFT + 3))) \
37 & (HASHSIZE - 1)))
38 #define SC_LOOKUP(wc) &sc_table[SC_HASH(wc)]
39
40 struct sleepqueue_chain {
41 struct umutex sc_lock;
42 int sc_enqcnt;
43 LIST_HEAD(, sleepqueue) sc_queues;
44 int sc_type;
45 };
46
47 static struct sleepqueue_chain sc_table[HASHSIZE];
48
49 void
_sleepq_init(void)50 _sleepq_init(void)
51 {
52 int i;
53
54 for (i = 0; i < HASHSIZE; ++i) {
55 LIST_INIT(&sc_table[i].sc_queues);
56 _thr_umutex_init(&sc_table[i].sc_lock);
57 }
58 }
59
60 struct sleepqueue *
_sleepq_alloc(void)61 _sleepq_alloc(void)
62 {
63 struct sleepqueue *sq;
64
65 sq = calloc(1, sizeof(struct sleepqueue));
66 TAILQ_INIT(&sq->sq_blocked);
67 SLIST_INIT(&sq->sq_freeq);
68 return (sq);
69 }
70
71 void
_sleepq_free(struct sleepqueue * sq)72 _sleepq_free(struct sleepqueue *sq)
73 {
74 free(sq);
75 }
76
77 void
_sleepq_lock(void * wchan)78 _sleepq_lock(void *wchan)
79 {
80 struct pthread *curthread = _get_curthread();
81 struct sleepqueue_chain *sc;
82
83 sc = SC_LOOKUP(wchan);
84 THR_LOCK_ACQUIRE_SPIN(curthread, &sc->sc_lock);
85 }
86
87 void
_sleepq_unlock(void * wchan)88 _sleepq_unlock(void *wchan)
89 {
90 struct sleepqueue_chain *sc;
91 struct pthread *curthread = _get_curthread();
92
93 sc = SC_LOOKUP(wchan);
94 THR_LOCK_RELEASE(curthread, &sc->sc_lock);
95 }
96
97 static inline struct sleepqueue *
lookup(struct sleepqueue_chain * sc,void * wchan)98 lookup(struct sleepqueue_chain *sc, void *wchan)
99 {
100 struct sleepqueue *sq;
101
102 LIST_FOREACH(sq, &sc->sc_queues, sq_hash)
103 if (sq->sq_wchan == wchan)
104 return (sq);
105 return (NULL);
106 }
107
108 struct sleepqueue *
_sleepq_lookup(void * wchan)109 _sleepq_lookup(void *wchan)
110 {
111 return (lookup(SC_LOOKUP(wchan), wchan));
112 }
113
114 void
_sleepq_add(void * wchan,struct pthread * td)115 _sleepq_add(void *wchan, struct pthread *td)
116 {
117 struct sleepqueue_chain *sc;
118 struct sleepqueue *sq;
119
120 sc = SC_LOOKUP(wchan);
121 sq = lookup(sc, wchan);
122 if (sq != NULL) {
123 SLIST_INSERT_HEAD(&sq->sq_freeq, td->sleepqueue, sq_flink);
124 } else {
125 sq = td->sleepqueue;
126 LIST_INSERT_HEAD(&sc->sc_queues, sq, sq_hash);
127 sq->sq_wchan = wchan;
128 /* sq->sq_type = type; */
129 }
130 td->sleepqueue = NULL;
131 td->wchan = wchan;
132 if (((++sc->sc_enqcnt << _thr_queuefifo) & 0xff) != 0)
133 TAILQ_INSERT_HEAD(&sq->sq_blocked, td, wle);
134 else
135 TAILQ_INSERT_TAIL(&sq->sq_blocked, td, wle);
136 }
137
138 int
_sleepq_remove(struct sleepqueue * sq,struct pthread * td)139 _sleepq_remove(struct sleepqueue *sq, struct pthread *td)
140 {
141 int rc;
142
143 TAILQ_REMOVE(&sq->sq_blocked, td, wle);
144 if (TAILQ_EMPTY(&sq->sq_blocked)) {
145 LIST_REMOVE(sq, sq_hash);
146 td->sleepqueue = sq;
147 rc = 0;
148 } else {
149 td->sleepqueue = SLIST_FIRST(&sq->sq_freeq);
150 SLIST_REMOVE_HEAD(&sq->sq_freeq, sq_flink);
151 rc = 1;
152 }
153 td->wchan = NULL;
154 return (rc);
155 }
156
157 void
_sleepq_drop(struct sleepqueue * sq,void (* cb)(struct pthread *,void * arg),void * arg)158 _sleepq_drop(struct sleepqueue *sq,
159 void (*cb)(struct pthread *, void *arg), void *arg)
160 {
161 struct pthread *td;
162 struct sleepqueue *sq2;
163
164 td = TAILQ_FIRST(&sq->sq_blocked);
165 if (td == NULL)
166 return;
167 LIST_REMOVE(sq, sq_hash);
168 TAILQ_REMOVE(&sq->sq_blocked, td, wle);
169 if (cb != NULL)
170 cb(td, arg);
171 td->sleepqueue = sq;
172 td->wchan = NULL;
173 sq2 = SLIST_FIRST(&sq->sq_freeq);
174 TAILQ_FOREACH(td, &sq->sq_blocked, wle) {
175 if (cb != NULL)
176 cb(td, arg);
177 td->sleepqueue = sq2;
178 td->wchan = NULL;
179 sq2 = SLIST_NEXT(sq2, sq_flink);
180 }
181 TAILQ_INIT(&sq->sq_blocked);
182 SLIST_INIT(&sq->sq_freeq);
183 }
184