Cleanup the TLS implementation:
[dragonfly.git] / lib / libthread_xu / thread / thr_sem.c
CommitLineData
71b3fa15
DX
1/*
2 * Copyright (C) 2005 David Xu <davidxu@freebsd.org>.
3 * Copyright (C) 2000 Jason Evans <jasone@freebsd.org>.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice(s), this list of conditions and the following disclaimer as
11 * the first lines of this file unmodified other than the possible
12 * addition of one or more copyright notices.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice(s), this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
25 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
27 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
28 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * $FreeBSD: src/lib/libpthread/thread/thr_sem.c,v 1.16 2004/12/18 18:07:37 deischen Exp $
9e2ee207 31 * $DragonFly: src/lib/libthread_xu/thread/thr_sem.c,v 1.3 2005/03/29 19:26:20 joerg Exp $
71b3fa15
DX
32 */
33
34#include <sys/queue.h>
9e2ee207
JS
35
36#include <machine/tls.h>
37
71b3fa15
DX
38#include <errno.h>
39#include <fcntl.h>
40#include <pthread.h>
41#include <semaphore.h>
42#include <stdlib.h>
43#include <time.h>
44
45#include "thr_private.h"
46
47__weak_reference(_sem_close, sem_close);
48__weak_reference(_sem_destroy, sem_destroy);
49__weak_reference(_sem_getvalue, sem_getvalue);
50__weak_reference(_sem_init, sem_init);
51__weak_reference(_sem_open, sem_open);
52__weak_reference(_sem_trywait, sem_trywait);
53__weak_reference(_sem_wait, sem_wait);
54__weak_reference(_sem_timedwait, sem_timedwait);
55__weak_reference(_sem_post, sem_post);
56__weak_reference(_sem_unlink, sem_unlink);
57
58/*
59 * Semaphore definitions.
60 */
61struct sem {
62#define SEM_MAGIC ((u_int32_t) 0x09fa4012)
63 u_int32_t magic;
64 volatile umtx_t count;
65 int semid; /* kernel based semaphore id. */
66};
67
68static inline int
69sem_check_validity(sem_t *sem)
70{
71
72 if ((sem != NULL) && ((*sem)->magic == SEM_MAGIC))
73 return (0);
74 else {
75 errno = EINVAL;
76 return (-1);
77 }
78}
79
80static sem_t
81sem_alloc(unsigned int value, int semid)
82{
83 sem_t sem;
84
85 if (value > SEM_VALUE_MAX) {
86 errno = EINVAL;
87 return (NULL);
88 }
89
90 sem = (sem_t)malloc(sizeof(struct sem));
91 if (sem == NULL) {
92 errno = ENOSPC;
93 return (NULL);
94 }
95 sem->magic = SEM_MAGIC;
96 sem->count = (u_int32_t)value;
97 sem->semid = semid;
98 return (sem);
99}
100
101int
102_sem_init(sem_t *sem, int pshared, unsigned int value)
103{
104 if (pshared != 0) {
105 /*
106 * We really can support pshared, but sem_t was
107 * defined as a pointer, if it is a structure,
108 * it will work between processes.
109 */
110 errno = EPERM;
111 return (-1);
112 }
113
114 (*sem) = sem_alloc(value, -1);
115 if ((*sem) == NULL)
116 return (-1);
117 return (0);
118}
119
120int
121_sem_destroy(sem_t *sem)
122{
123 if (sem_check_validity(sem) != 0)
124 return (-1);
125
126 free(*sem);
127 return (0);
128}
129
130sem_t *
131_sem_open(const char *name, int oflag, ...)
132{
133 errno = ENOSYS;
134 return SEM_FAILED;
135}
136
137int
138_sem_close(sem_t *sem)
139{
140 errno = ENOSYS;
141 return -1;
142}
143
144int
145_sem_unlink(const char *name)
146{
147 errno = ENOSYS;
148 return -1;
149}
150
151int
152_sem_getvalue(sem_t * __restrict sem, int * __restrict sval)
153{
154 if (sem_check_validity(sem) != 0)
155 return (-1);
156
157 *sval = (*sem)->count;
158 return (0);
159}
160
161int
162_sem_trywait(sem_t *sem)
163{
164 int val;
165
166 if (sem_check_validity(sem) != 0)
167 return (-1);
168
169 while ((val = (*sem)->count) > 0) {
170 if (atomic_cmpset_int(&(*sem)->count, val, val - 1))
171 return (0);
172 }
173 errno = EAGAIN;
174 return (-1);
175}
176
177int
178_sem_wait(sem_t *sem)
179{
180 struct pthread *curthread;
181 int val, oldcancel, retval;
182
183 if (sem_check_validity(sem) != 0)
184 return (-1);
185
9e2ee207 186 curthread = tls_get_curthread();
71b3fa15
DX
187 _pthread_testcancel();
188 do {
189 while ((val = (*sem)->count) > 0) {
190 if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1))
191 return (0);
192 }
193 oldcancel = _thr_cancel_enter(curthread);
9219c44c 194 retval = _thr_umtx_wait(&(*sem)->count, 0, NULL, 0);
71b3fa15
DX
195 _thr_cancel_leave(curthread, oldcancel);
196 } while (retval == 0);
197 errno = retval;
198 return (-1);
199}
200
201int
202_sem_timedwait(sem_t * __restrict sem, struct timespec * __restrict abstime)
203{
204 struct timespec ts, ts2;
205 struct pthread *curthread;
206 int val, oldcancel, retval;
207
208 if (sem_check_validity(sem) != 0)
209 return (-1);
210
9e2ee207 211 curthread = tls_get_curthread();
71b3fa15
DX
212
213 /*
214 * The timeout argument is only supposed to
215 * be checked if the thread would have blocked.
216 */
217 _pthread_testcancel();
218 do {
219 while ((val = (*sem)->count) > 0) {
220 if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1))
221 return (0);
222 }
223 if (abstime == NULL) {
224 errno = EINVAL;
225 return (-1);
226 }
227 clock_gettime(CLOCK_REALTIME, &ts);
228 TIMESPEC_SUB(&ts2, abstime, &ts);
229 oldcancel = _thr_cancel_enter(curthread);
9219c44c
DX
230 retval = _thr_umtx_wait(&(*sem)->count, 0, &ts2,
231 CLOCK_REALTIME);
71b3fa15
DX
232 _thr_cancel_leave(curthread, oldcancel);
233 } while (retval == 0);
234 errno = retval;
235 return (-1);
236}
237
238int
239_sem_post(sem_t *sem)
240{
241 int val;
242
243 if (sem_check_validity(sem) != 0)
244 return (-1);
245
246 /*
247 * sem_post() is required to be safe to call from within
248 * signal handlers, these code should work as that.
249 */
250 do {
251 val = (*sem)->count;
252 } while (!atomic_cmpset_acq_int(&(*sem)->count, val, val + 1));
253 _thr_umtx_wake(&(*sem)->count, val + 1);
254 return (0);
255}