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. Neither the name of the author nor the names of any co-contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD$
30 */
31
32#include "namespace.h"
33#include <signal.h>
34#include <stdlib.h>
35#include <string.h>
36#include <errno.h>
37#include <pthread.h>
38#include "un-namespace.h"
39#include "libc_private.h"
40
41#include "thr_private.h"
42
43/* Static variables: */
44struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
45
46__weak_reference(_pthread_key_create, pthread_key_create);
47__weak_reference(_pthread_key_delete, pthread_key_delete);
48__weak_reference(_pthread_getspecific, pthread_getspecific);
49__weak_reference(_pthread_setspecific, pthread_setspecific);
50
51
52int
53_pthread_key_create(pthread_key_t *key, void (*destructor) (void *))
54{
55	struct pthread *curthread;
56	int i;
57
58	_thr_check_init();
59
60	curthread = _get_curthread();
61
62	/* Lock the key table: */
63	THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
64	for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
65
66		if (_thread_keytable[i].allocated == 0) {
67			_thread_keytable[i].allocated = 1;
68			_thread_keytable[i].destructor = destructor;
69			_thread_keytable[i].seqno++;
70
71			/* Unlock the key table: */
72			THR_LOCK_RELEASE(curthread, &_keytable_lock);
73			*key = i + 1;
74			return (0);
75		}
76
77	}
78	/* Unlock the key table: */
79	THR_LOCK_RELEASE(curthread, &_keytable_lock);
80	return (EAGAIN);
81}
82
83int
84_pthread_key_delete(pthread_key_t userkey)
85{
86	struct pthread *curthread = _get_curthread();
87	int key = userkey - 1;
88	int ret = 0;
89
90	if ((unsigned int)key < PTHREAD_KEYS_MAX) {
91		/* Lock the key table: */
92		THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
93
94		if (_thread_keytable[key].allocated)
95			_thread_keytable[key].allocated = 0;
96		else
97			ret = EINVAL;
98
99		/* Unlock the key table: */
100		THR_LOCK_RELEASE(curthread, &_keytable_lock);
101	} else
102		ret = EINVAL;
103	return (ret);
104}
105
106void
107_thread_cleanupspecific(void)
108{
109	struct pthread	*curthread = _get_curthread();
110	void		(*destructor)( void *);
111	const void	*data = NULL;
112	int		key;
113	int		i;
114
115	if (curthread->specific == NULL)
116		return;
117
118	/* Lock the key table: */
119	THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
120	for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) &&
121	    (curthread->specific_data_count > 0); i++) {
122		for (key = 0; (key < PTHREAD_KEYS_MAX) &&
123		    (curthread->specific_data_count > 0); key++) {
124			destructor = NULL;
125
126			if (_thread_keytable[key].allocated &&
127			    (curthread->specific[key].data != NULL)) {
128				if (curthread->specific[key].seqno ==
129				    _thread_keytable[key].seqno) {
130					data = curthread->specific[key].data;
131					destructor = _thread_keytable[key].destructor;
132				}
133				curthread->specific[key].data = NULL;
134				curthread->specific_data_count--;
135			}
136			else if (curthread->specific[key].data != NULL) {
137				/*
138				 * This can happen if the key is deleted via
139				 * pthread_key_delete without first setting the value
140				 * to NULL in all threads.  POSIX says that the
141				 * destructor is not invoked in this case.
142				 */
143				curthread->specific[key].data = NULL;
144				curthread->specific_data_count--;
145			}
146
147			/*
148			 * If there is a destructor, call it
149			 * with the key table entry unlocked:
150			 */
151			if (destructor != NULL) {
152				/*
153				 * Don't hold the lock while calling the
154				 * destructor:
155				 */
156				THR_LOCK_RELEASE(curthread, &_keytable_lock);
157				destructor(__DECONST(void *, data));
158				THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
159			}
160		}
161	}
162	THR_LOCK_RELEASE(curthread, &_keytable_lock);
163	free(curthread->specific);
164	curthread->specific = NULL;
165	if (curthread->specific_data_count > 0)
166		stderr_debug("Thread %p has exited with leftover "
167		    "thread-specific data after %d destructor iterations\n",
168		    curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
169}
170
171static inline struct pthread_specific_elem *
172pthread_key_allocate_data(void)
173{
174	struct pthread_specific_elem *new_data;
175
176	new_data = (struct pthread_specific_elem *)
177	    calloc(1, sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
178	return (new_data);
179}
180
181int
182_pthread_setspecific(pthread_key_t userkey, const void *value)
183{
184	struct pthread	*pthread;
185	pthread_key_t	key = userkey - 1;
186	int		ret = 0;
187
188	/* Point to the running thread: */
189	pthread = _get_curthread();
190
191	if ((pthread->specific) ||
192	    (pthread->specific = pthread_key_allocate_data())) {
193		if ((unsigned int)key < PTHREAD_KEYS_MAX) {
194			if (_thread_keytable[key].allocated) {
195				if (pthread->specific[key].data == NULL) {
196					if (value != NULL)
197						pthread->specific_data_count++;
198				} else if (value == NULL)
199					pthread->specific_data_count--;
200				pthread->specific[key].data = value;
201				pthread->specific[key].seqno =
202				    _thread_keytable[key].seqno;
203				ret = 0;
204			} else
205				ret = EINVAL;
206		} else
207			ret = EINVAL;
208	} else
209		ret = ENOMEM;
210	return (ret);
211}
212
213void *
214_pthread_getspecific(pthread_key_t userkey)
215{
216	struct pthread	*pthread;
217	pthread_key_t	key = userkey - 1;
218	const void	*data;
219
220	/* Point to the running thread: */
221	pthread = _get_curthread();
222
223	/* Check if there is specific data: */
224	if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) {
225		/* Check if this key has been used before: */
226		if (_thread_keytable[key].allocated &&
227		    (pthread->specific[key].seqno == _thread_keytable[key].seqno)) {
228			/* Return the value: */
229			data = pthread->specific[key].data;
230		} else {
231			/*
232			 * This key has not been used before, so return NULL
233			 * instead:
234			 */
235			data = NULL;
236		}
237	} else
238		/* No specific data has been created, so just return NULL: */
239		data = NULL;
240	return (__DECONST(void *, data));
241}
242
243void
244_thr_tsd_unload(struct dl_phdr_info *phdr_info)
245{
246	struct pthread *curthread = _get_curthread();
247	void (*destructor)(void *);
248	int key;
249
250	THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
251	for (key = 0; key < PTHREAD_KEYS_MAX; key++) {
252		if (_thread_keytable[key].allocated) {
253			destructor = _thread_keytable[key].destructor;
254			if (destructor != NULL) {
255				if (__elf_phdr_match_addr(phdr_info, destructor))
256					_thread_keytable[key].destructor = NULL;
257			}
258		}
259	}
260	THR_LOCK_RELEASE(curthread, &_keytable_lock);
261}
262