xref: /netbsd-src/lib/libc/thread-stub/thread-stub.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: thread-stub.c,v 1.19 2007/12/14 17:06:07 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 __RCSID("$NetBSD: thread-stub.c,v 1.19 2007/12/14 17:06:07 christos Exp $");
42 #endif /* LIBC_SCCS and not lint */
43 
44 /*
45  * Stubs for thread operations, for use when threads are not used by
46  * the application.  See "reentrant.h" for details.
47  */
48 
49 #ifdef _REENTRANT
50 
51 #define	__LIBC_THREAD_STUBS
52 
53 #include "namespace.h"
54 #include "reentrant.h"
55 
56 #include <errno.h>
57 #include <signal.h>
58 #include <stdlib.h>
59 #include <unistd.h>
60 
61 extern int __isthreaded;
62 
63 #define	DIE()	(void)kill(getpid(), SIGABRT)
64 
65 #define	CHECK_NOT_THREADED_ALWAYS()	\
66 do {					\
67 	if (__isthreaded)		\
68 		DIE();			\
69 } while (/*CONSTCOND*/0)
70 
71 #if 1
72 #define	CHECK_NOT_THREADED()	CHECK_NOT_THREADED_ALWAYS()
73 #else
74 #define	CHECK_NOT_THREADED()	/* nothing */
75 #endif
76 
77 /* libpthread init */
78 
79 void	__libc_thr_init(void);
80 void	__libc_thr_init_stub(void);
81 
82 __weak_alias(__libc_thr_init,__libc_thr_init_stub)
83 
84 void
85 __libc_thr_init_stub(void)
86 {
87 
88 	/* nothing, may be overridden by libpthread */
89 }
90 
91 /* mutexes */
92 
93 int	__libc_mutex_init_stub(mutex_t *, const mutexattr_t *);
94 int	__libc_mutex_catchall_stub(mutex_t *);
95 
96 __weak_alias(__libc_mutex_init,__libc_mutex_init_stub)
97 __weak_alias(__libc_mutex_lock,__libc_mutex_catchall_stub)
98 __weak_alias(__libc_mutex_trylock,__libc_mutex_catchall_stub)
99 __weak_alias(__libc_mutex_unlock,__libc_mutex_catchall_stub)
100 __weak_alias(__libc_mutex_destroy,__libc_mutex_catchall_stub)
101 
102 int	__libc_mutexattr_catchall_stub(mutexattr_t *);
103 int	__libc_mutexattr_settype_stub(mutexattr_t *, int);
104 
105 __weak_alias(__libc_mutexattr_init,__libc_mutexattr_catchall_stub)
106 __weak_alias(__libc_mutexattr_destroy,__libc_mutexattr_catchall_stub)
107 __weak_alias(__libc_mutexattr_settype,__libc_mutexattr_settype_stub)
108 
109 int
110 __libc_mutex_init_stub(mutex_t *m, const mutexattr_t *a)
111 {
112 	/* LINTED deliberate lack of effect */
113 	(void)m;
114 	/* LINTED deliberate lack of effect */
115 	(void)a;
116 
117 	CHECK_NOT_THREADED();
118 
119 	return (0);
120 }
121 
122 int
123 __libc_mutex_catchall_stub(mutex_t *m)
124 {
125 	/* LINTED deliberate lack of effect */
126 	(void)m;
127 
128 	CHECK_NOT_THREADED();
129 
130 	return (0);
131 }
132 
133 int
134 __libc_mutexattr_settype_stub(mutexattr_t *ma, int type)
135 {
136 	/* LINTED deliberate lack of effect */
137 	(void)ma;
138 	/* LINTED deliberate lack of effect */
139 	(void)type;
140 
141 	return (0);
142 }
143 
144 int
145 __libc_mutexattr_catchall_stub(mutexattr_t *ma)
146 {
147 	/* LINTED deliberate lack of effect */
148 	(void)ma;
149 
150 	CHECK_NOT_THREADED();
151 
152 	return (0);
153 }
154 
155 /* condition variables */
156 
157 int	__libc_cond_init_stub(cond_t *, const condattr_t *);
158 int	__libc_cond_wait_stub(cond_t *, mutex_t *);
159 int	__libc_cond_timedwait_stub(cond_t *, mutex_t *,
160 				   const struct timespec *);
161 int	__libc_cond_catchall_stub(cond_t *);
162 
163 __weak_alias(__libc_cond_init,__libc_cond_init_stub)
164 __weak_alias(__libc_cond_signal,__libc_cond_catchall_stub)
165 __weak_alias(__libc_cond_broadcast,__libc_cond_catchall_stub)
166 __weak_alias(__libc_cond_wait,__libc_cond_wait_stub)
167 __weak_alias(__libc_cond_timedwait,__libc_cond_timedwait_stub)
168 __weak_alias(__libc_cond_destroy,__libc_cond_catchall_stub)
169 
170 int
171 __libc_cond_init_stub(cond_t *c, const condattr_t *a)
172 {
173 	/* LINTED deliberate lack of effect */
174 	(void)c;
175 	/* LINTED deliberate lack of effect */
176 	(void)a;
177 
178 	CHECK_NOT_THREADED();
179 
180 	return (0);
181 }
182 
183 int
184 __libc_cond_wait_stub(cond_t *c, mutex_t *m)
185 {
186 	/* LINTED deliberate lack of effect */
187 	(void)c;
188 	/* LINTED deliberate lack of effect */
189 	(void)m;
190 
191 	CHECK_NOT_THREADED();
192 
193 	return (0);
194 }
195 
196 int
197 __libc_cond_timedwait_stub(cond_t *c, mutex_t *m, const struct timespec *t)
198 {
199 	/* LINTED deliberate lack of effect */
200 	(void)c;
201 	/* LINTED deliberate lack of effect */
202 	(void)m;
203 	/* LINTED deliberate lack of effect */
204 	(void)t;
205 
206 	CHECK_NOT_THREADED();
207 
208 	return (0);
209 }
210 
211 int
212 __libc_cond_catchall_stub(cond_t *c)
213 {
214 	/* LINTED deliberate lack of effect */
215 	(void)c;
216 
217 	CHECK_NOT_THREADED();
218 
219 	return (0);
220 }
221 
222 
223 /* read-write locks */
224 
225 int	__libc_rwlock_init_stub(rwlock_t *, rwlockattr_t *);
226 int	__libc_rwlock_catchall_stub(rwlock_t *);
227 
228 __weak_alias(__libc_rwlock_init,__libc_rwlock_init_stub)
229 __weak_alias(__libc_rwlock_rdlock,__libc_rwlock_catchall_stub)
230 __weak_alias(__libc_rwlock_wrlock,__libc_rwlock_catchall_stub)
231 __weak_alias(__libc_rwlock_tryrdlock,__libc_rwlock_catchall_stub)
232 __weak_alias(__libc_rwlock_trywrlock,__libc_rwlock_catchall_stub)
233 __weak_alias(__libc_rwlock_unlock,__libc_rwlock_catchall_stub)
234 __weak_alias(__libc_rwlock_destroy,__libc_rwlock_catchall_stub)
235 
236 int
237 __libc_rwlock_init_stub(rwlock_t *l, rwlockattr_t *a)
238 {
239 	/* LINTED deliberate lack of effect */
240 	(void)l;
241 	/* LINTED deliberate lack of effect */
242 	(void)a;
243 
244 	CHECK_NOT_THREADED();
245 
246 	return (0);
247 }
248 
249 int
250 __libc_rwlock_catchall_stub(rwlock_t *l)
251 {
252 	/* LINTED deliberate lack of effect */
253 	(void)l;
254 
255 	CHECK_NOT_THREADED();
256 
257 	return (0);
258 }
259 
260 
261 /*
262  * thread-specific data; we need to actually provide a simple TSD
263  * implementation, since some thread-safe libraries want to use it.
264  */
265 
266 #define	TSD_KEYS_MAX	64
267 
268 static struct {
269 	void *tsd_val;
270 	void (*tsd_dtor)(void *);
271 	int tsd_inuse;
272 } __libc_tsd[TSD_KEYS_MAX];
273 static int __libc_tsd_nextkey;
274 
275 int	__libc_thr_keycreate_stub(thread_key_t *, void (*)(void *));
276 int	__libc_thr_setspecific_stub(thread_key_t, const void *);
277 void	*__libc_thr_getspecific_stub(thread_key_t);
278 int	__libc_thr_keydelete_stub(thread_key_t);
279 
280 __weak_alias(__libc_thr_keycreate,__libc_thr_keycreate_stub)
281 __weak_alias(__libc_thr_setspecific,__libc_thr_setspecific_stub)
282 __weak_alias(__libc_thr_getspecific,__libc_thr_getspecific_stub)
283 __weak_alias(__libc_thr_keydelete,__libc_thr_keydelete_stub)
284 
285 int
286 __libc_thr_keycreate_stub(thread_key_t *k, void (*d)(void *))
287 {
288 	int i;
289 
290 	for (i = __libc_tsd_nextkey; i < TSD_KEYS_MAX; i++) {
291 		if (__libc_tsd[i].tsd_inuse == 0)
292 			goto out;
293 	}
294 
295 	for (i = 0; i < __libc_tsd_nextkey; i++) {
296 		if (__libc_tsd[i].tsd_inuse == 0)
297 			goto out;
298 	}
299 
300 	return (EAGAIN);
301 
302  out:
303 	/*
304 	 * XXX We don't actually do anything with the destructor.  We
305 	 * XXX probably should.
306 	 */
307 	__libc_tsd[i].tsd_inuse = 1;
308 	__libc_tsd_nextkey = (i + i) % TSD_KEYS_MAX;
309 	__libc_tsd[i].tsd_dtor = d;
310 	*k = i;
311 
312 	return (0);
313 }
314 
315 int
316 __libc_thr_setspecific_stub(thread_key_t k, const void *v)
317 {
318 
319 	__libc_tsd[k].tsd_val = __UNCONST(v);
320 
321 	return (0);
322 }
323 
324 void *
325 __libc_thr_getspecific_stub(thread_key_t k)
326 {
327 
328 	return (__libc_tsd[k].tsd_val);
329 }
330 
331 int
332 __libc_thr_keydelete_stub(thread_key_t k)
333 {
334 
335 	/*
336 	 * XXX Do not recycle key; see big comment in libpthread.
337 	 */
338 
339 	__libc_tsd[k].tsd_dtor = NULL;
340 
341 	return (0);
342 }
343 
344 
345 /* misc. */
346 
347 int	__libc_thr_once_stub(once_t *, void (*)(void));
348 int	__libc_thr_sigsetmask_stub(int, const sigset_t *, sigset_t *);
349 thr_t	__libc_thr_self_stub(void);
350 int	__libc_thr_yield_stub(void);
351 int	__libc_thr_create_stub(thr_t *, const thrattr_t *,
352 	    void *(*)(void *), void *);
353 void	__libc_thr_exit_stub(void *);
354 int	*__libc_thr_errno_stub(void);
355 int	__libc_thr_setcancelstate_stub(int, int *);
356 int	__libc_thr_equal_stub(pthread_t, pthread_t);
357 unsigned int __libc_thr_curcpu_stub(void);
358 
359 __weak_alias(__libc_thr_once,__libc_thr_once_stub)
360 __weak_alias(__libc_thr_sigsetmask,__libc_thr_sigsetmask_stub)
361 __weak_alias(__libc_thr_self,__libc_thr_self_stub)
362 __weak_alias(__libc_thr_yield,__libc_thr_yield_stub)
363 __weak_alias(__libc_thr_create,__libc_thr_create_stub)
364 __weak_alias(__libc_thr_exit,__libc_thr_exit_stub)
365 __weak_alias(__libc_thr_errno,__libc_thr_errno_stub)
366 __weak_alias(__libc_thr_setcancelstate,__libc_thr_setcancelstate_stub)
367 __weak_alias(__libc_thr_equal,__libc_thr_equal_stub)
368 __weak_alias(__libc_thr_curcpu,__libc_thr_curcpu_stub)
369 
370 
371 int
372 __libc_thr_once_stub(once_t *o, void (*r)(void))
373 {
374 
375 	/* XXX Knowledge of libpthread types. */
376 
377 	if (o->pto_done == 0) {
378 		(*r)();
379 		o->pto_done = 1;
380 	}
381 
382 	return (0);
383 }
384 
385 int
386 __libc_thr_sigsetmask_stub(int h, const sigset_t *s, sigset_t *o)
387 {
388 
389 	CHECK_NOT_THREADED();
390 
391 	return sigprocmask(h, s, o);
392 }
393 
394 thr_t
395 __libc_thr_self_stub(void)
396 {
397 
398 	return ((thr_t) -1);
399 }
400 
401 int
402 __libc_thr_yield_stub(void)
403 {
404 
405 	/* Nothing to do. */
406 	return (0);
407 }
408 
409 int
410 __libc_thr_create_stub(thr_t *tp, const thrattr_t *ta,
411     void *(*f)(void *), void *a)
412 {
413 	/* LINTED deliberate lack of effect */
414 	(void)tp;
415 	/* LINTED deliberate lack of effect */
416 	(void)ta;
417 	/* LINTED deliberate lack of effect */
418 	(void)f;
419 	/* LINTED deliberate lack of effect */
420 	(void)a;
421 
422 	DIE();
423 
424 	return (EOPNOTSUPP);
425 }
426 
427 void
428 __libc_thr_exit_stub(void *v)
429 {
430 	/* LINTED deliberate lack of effect */
431 	(void)v;
432 	exit(0);
433 }
434 
435 int
436 __libc_thr_setcancelstate_stub(int new, int *old)
437 {
438 	/* LINTED deliberate lack of effect */
439 	(void)new;
440 
441 	/* LINTED deliberate lack of effect */
442 	(void)old;
443 
444 	CHECK_NOT_THREADED();
445 
446 	return (0);
447 }
448 
449 int
450 __libc_thr_equal_stub(pthread_t t1, pthread_t t2)
451 {
452 
453 	/* assert that t1=t2=pthread_self() */
454 	return (t1 == t2);
455 }
456 
457 int *
458 __libc_thr_errno_stub(void)
459 {
460 
461 	DIE();
462 
463 	return (NULL);
464 }
465 
466 unsigned int
467 __libc_thr_curcpu_stub(void)
468 {
469 
470 	return (0);
471 }
472 
473 #endif /* _REENTRANT */
474