thr_spec.c revision 71581 
1/*
2 * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD: head/lib/libkse/thread/thr_spec.c 71581 2001-01-24 13:03:38Z deischen $
33 */
34#include <signal.h>
35#include <stdlib.h>
36#include <string.h>
37#include <errno.h>
38#include <pthread.h>
39#include "pthread_private.h"
40
41/* Static variables: */
42static	struct pthread_key key_table[PTHREAD_KEYS_MAX];
43
44#pragma weak	pthread_key_create=_pthread_key_create
45#pragma weak	pthread_key_delete=_pthread_key_delete
46#pragma weak	pthread_getspecific=_pthread_getspecific
47#pragma weak	pthread_setspecific=_pthread_setspecific
48
49
50int
51_pthread_key_create(pthread_key_t * key, void (*destructor) (void *))
52{
53	for ((*key) = 0; (*key) < PTHREAD_KEYS_MAX; (*key)++) {
54		/* Lock the key table entry: */
55		_SPINLOCK(&key_table[*key].lock);
56
57		if (key_table[(*key)].allocated == 0) {
58			key_table[(*key)].allocated = 1;
59			key_table[(*key)].destructor = destructor;
60
61			/* Unlock the key table entry: */
62			_SPINUNLOCK(&key_table[*key].lock);
63			return (0);
64		}
65
66		/* Unlock the key table entry: */
67		_SPINUNLOCK(&key_table[*key].lock);
68	}
69	return (EAGAIN);
70}
71
72int
73_pthread_key_delete(pthread_key_t key)
74{
75	int ret = 0;
76
77	if (key < PTHREAD_KEYS_MAX) {
78		/* Lock the key table entry: */
79		_SPINLOCK(&key_table[key].lock);
80
81		if (key_table[key].allocated)
82			key_table[key].allocated = 0;
83		else
84			ret = EINVAL;
85
86		/* Unlock the key table entry: */
87		_SPINUNLOCK(&key_table[key].lock);
88	} else
89		ret = EINVAL;
90	return (ret);
91}
92
93void
94_thread_cleanupspecific(void)
95{
96	struct pthread	*curthread = _get_curthread();
97	void		*data = NULL;
98	int		key;
99	int		itr;
100	void		(*destructor)( void *);
101
102	for (itr = 0; itr < PTHREAD_DESTRUCTOR_ITERATIONS; itr++) {
103		for (key = 0; key < PTHREAD_KEYS_MAX; key++) {
104			if (curthread->specific_data_count) {
105				/* Lock the key table entry: */
106				_SPINLOCK(&key_table[key].lock);
107				destructor = NULL;
108
109				if (key_table[key].allocated) {
110					if (curthread->specific_data[key]) {
111						data = (void *) curthread->specific_data[key];
112						curthread->specific_data[key] = NULL;
113						curthread->specific_data_count--;
114						destructor = key_table[key].destructor;
115					}
116				}
117
118				/* Unlock the key table entry: */
119				_SPINUNLOCK(&key_table[key].lock);
120
121				/*
122				 * If there is a destructore, call it
123				 * with the key table entry unlocked:
124				 */
125				if (destructor)
126					destructor(data);
127			} else {
128				free(curthread->specific_data);
129				curthread->specific_data = NULL;
130				return;
131			}
132		}
133	}
134	free(curthread->specific_data);
135	curthread->specific_data = NULL;
136}
137
138static inline const void **
139pthread_key_allocate_data(void)
140{
141	const void    **new_data;
142	if ((new_data = (const void **) malloc(sizeof(void *) * PTHREAD_KEYS_MAX)) != NULL) {
143		memset((void *) new_data, 0, sizeof(void *) * PTHREAD_KEYS_MAX);
144	}
145	return (new_data);
146}
147
148int
149_pthread_setspecific(pthread_key_t key, const void *value)
150{
151	struct pthread	*pthread;
152	int		ret = 0;
153
154	/* Point to the running thread: */
155	pthread = _get_curthread();
156
157	if ((pthread->specific_data) ||
158	    (pthread->specific_data = pthread_key_allocate_data())) {
159		if (key < PTHREAD_KEYS_MAX) {
160			if (key_table[key].allocated) {
161				if (pthread->specific_data[key] == NULL) {
162					if (value != NULL)
163						pthread->specific_data_count++;
164				} else {
165					if (value == NULL)
166						pthread->specific_data_count--;
167				}
168				pthread->specific_data[key] = value;
169				ret = 0;
170			} else
171				ret = EINVAL;
172		} else
173			ret = EINVAL;
174	} else
175		ret = ENOMEM;
176	return (ret);
177}
178
179void *
180_pthread_getspecific(pthread_key_t key)
181{
182	struct pthread	*pthread;
183	void		*data;
184
185	/* Point to the running thread: */
186	pthread = _get_curthread();
187
188	/* Check if there is specific data: */
189	if (pthread->specific_data != NULL && key < PTHREAD_KEYS_MAX) {
190		/* Check if this key has been used before: */
191		if (key_table[key].allocated) {
192			/* Return the value: */
193			data = (void *) pthread->specific_data[key];
194		} else {
195			/*
196			 * This key has not been used before, so return NULL
197			 * instead:
198			 */
199			data = NULL;
200		}
201	} else
202		/* No specific data has been created, so just return NULL: */
203		data = NULL;
204	return (data);
205}
206