thr_spec.c revision 36697 
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 REGENTS 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 */
33#include <signal.h>
34#include <stdlib.h>
35#include <string.h>
36#include <errno.h>
37#ifdef _THREAD_SAFE
38#include <pthread.h>
39#include "pthread_private.h"
40
41/* Static variables: */
42static	struct pthread_key key_table[PTHREAD_KEYS_MAX];
43
44int
45pthread_key_create(pthread_key_t * key, void (*destructor) (void *))
46{
47	for ((*key) = 0; (*key) < PTHREAD_KEYS_MAX; (*key)++) {
48		/* Lock the key table entry: */
49		_spinlock(&key_table[*key].access_lock);
50
51		if (key_table[(*key)].allocated == 0) {
52			key_table[(*key)].allocated = 1;
53			key_table[(*key)].destructor = destructor;
54
55			/* Unlock the key table entry: */
56			_atomic_unlock(&key_table[*key].access_lock);
57			return (0);
58		}
59
60		/* Unlock the key table entry: */
61		_atomic_unlock(&key_table[*key].access_lock);
62	}
63	return (EAGAIN);
64}
65
66int
67pthread_key_delete(pthread_key_t key)
68{
69	int ret = 0;
70
71	if (key < PTHREAD_KEYS_MAX) {
72		/* Lock the key table entry: */
73		_spinlock(&key_table[key].access_lock);
74
75		if (key_table[key].allocated)
76			key_table[key].allocated = 0;
77		else
78			ret = EINVAL;
79
80		/* Unlock the key table entry: */
81		_atomic_unlock(&key_table[key].access_lock);
82	} else
83		ret = EINVAL;
84	return (ret);
85}
86
87void
88_thread_cleanupspecific(void)
89{
90	void           *data;
91	int             key;
92	int             itr;
93
94	for (itr = 0; itr < PTHREAD_DESTRUCTOR_ITERATIONS; itr++) {
95		for (key = 0; key < PTHREAD_KEYS_MAX; key++) {
96			if (_thread_run->specific_data_count) {
97				/* Lock the key table entry: */
98				_spinlock(&key_table[key].access_lock);
99
100				if (key_table[key].allocated) {
101					if (_thread_run->specific_data[key]) {
102						data = (void *) _thread_run->specific_data[key];
103						_thread_run->specific_data[key] = NULL;
104						_thread_run->specific_data_count--;
105						if (key_table[key].destructor)
106							key_table[key].destructor(data);
107					}
108				}
109
110				/* Unlock the key table entry: */
111				_atomic_unlock(&key_table[key].access_lock);
112			} else {
113				free(_thread_run->specific_data);
114				return;
115			}
116		}
117	}
118	free(_thread_run->specific_data);
119}
120
121static inline const void **
122pthread_key_allocate_data(void)
123{
124	const void    **new_data;
125	if ((new_data = (const void **) malloc(sizeof(void *) * PTHREAD_KEYS_MAX)) != NULL) {
126		memset((void *) new_data, 0, sizeof(void *) * PTHREAD_KEYS_MAX);
127	}
128	return (new_data);
129}
130
131int
132pthread_setspecific(pthread_key_t key, const void *value)
133{
134	pthread_t       pthread;
135	int             ret = 0;
136
137	/* Point to the running thread: */
138	pthread = _thread_run;
139
140	if ((pthread->specific_data) ||
141	    (pthread->specific_data = pthread_key_allocate_data())) {
142		if (key < PTHREAD_KEYS_MAX) {
143			/* Lock the key table entry: */
144			_spinlock(&key_table[key].access_lock);
145
146			if (key_table[key].allocated) {
147				if (pthread->specific_data[key] == NULL) {
148					if (value != NULL)
149						pthread->specific_data_count++;
150				} else {
151					if (value == NULL)
152						pthread->specific_data_count--;
153				}
154				pthread->specific_data[key] = value;
155				ret = 0;
156			} else
157				ret = EINVAL;
158
159			/* Unlock the key table entry: */
160			_atomic_unlock(&key_table[key].access_lock);
161
162		} else
163			ret = EINVAL;
164	} else
165		ret = ENOMEM;
166	return (ret);
167}
168
169void *
170pthread_getspecific(pthread_key_t key)
171{
172	pthread_t       pthread;
173	void		*data;
174
175	/* Point to the running thread: */
176	pthread = _thread_run;
177
178	/* Check if there is specific data: */
179	if (pthread->specific_data != NULL && key < PTHREAD_KEYS_MAX) {
180		/* Lock the key table entry: */
181		_spinlock(&key_table[key].access_lock);
182
183		/* Check if this key has been used before: */
184		if (key_table[key].allocated) {
185			/* Return the value: */
186			data = (void *) pthread->specific_data[key];
187		} else {
188			/*
189			 * This key has not been used before, so return NULL
190			 * instead:
191			 */
192			data = NULL;
193		}
194
195		/* Unlock the key table entry: */
196		_atomic_unlock(&key_table[key].access_lock);
197	} else
198		/* No specific data has been created, so just return NULL: */
199		data = NULL;
200	return (data);
201}
202#endif
203