xref: /netbsd-src/lib/libc/thread-stub/thread-stub.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: thread-stub.c,v 1.21 2009/01/30 23:21:03 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2009 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 __RCSID("$NetBSD: thread-stub.c,v 1.21 2009/01/30 23:21:03 ad Exp $");
35 #endif /* LIBC_SCCS and not lint */
36 
37 /*
38  * Stubs for thread operations, for use when threads are not used by
39  * the application.  See "reentrant.h" for details.
40  */
41 
42 #ifdef _REENTRANT
43 
44 #define	__LIBC_THREAD_STUBS
45 
46 #include "namespace.h"
47 #include "reentrant.h"
48 
49 #include <errno.h>
50 #include <signal.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 
54 extern int __isthreaded;
55 
56 #define	DIE()	(void)raise(SIGABRT)
57 
58 #define	CHECK_NOT_THREADED_ALWAYS()	\
59 do {					\
60 	if (__isthreaded)		\
61 		DIE();			\
62 } while (/*CONSTCOND*/0)
63 
64 #if 1
65 #define	CHECK_NOT_THREADED()	CHECK_NOT_THREADED_ALWAYS()
66 #else
67 #define	CHECK_NOT_THREADED()	/* nothing */
68 #endif
69 
70 /* libpthread init */
71 
72 void	__libc_thr_init(void);
73 void	__libc_thr_init_stub(void);
74 
75 __weak_alias(__libc_thr_init,__libc_thr_init_stub)
76 
77 void
78 __libc_thr_init_stub(void)
79 {
80 
81 	/* nothing, may be overridden by libpthread */
82 }
83 
84 /* mutexes */
85 
86 int	__libc_mutex_init_stub(mutex_t *, const mutexattr_t *);
87 int	__libc_mutex_catchall_stub(mutex_t *);
88 
89 __weak_alias(__libc_mutex_init,__libc_mutex_init_stub)
90 __weak_alias(__libc_mutex_lock,__libc_mutex_catchall_stub)
91 __weak_alias(__libc_mutex_trylock,__libc_mutex_catchall_stub)
92 __weak_alias(__libc_mutex_unlock,__libc_mutex_catchall_stub)
93 __weak_alias(__libc_mutex_destroy,__libc_mutex_catchall_stub)
94 
95 int	__libc_mutexattr_catchall_stub(mutexattr_t *);
96 int	__libc_mutexattr_settype_stub(mutexattr_t *, int);
97 
98 __weak_alias(__libc_mutexattr_init,__libc_mutexattr_catchall_stub)
99 __weak_alias(__libc_mutexattr_destroy,__libc_mutexattr_catchall_stub)
100 __weak_alias(__libc_mutexattr_settype,__libc_mutexattr_settype_stub)
101 
102 int
103 __libc_mutex_init_stub(mutex_t *m, const mutexattr_t *a)
104 {
105 	/* LINTED deliberate lack of effect */
106 	(void)m;
107 	/* LINTED deliberate lack of effect */
108 	(void)a;
109 
110 	CHECK_NOT_THREADED();
111 
112 	return (0);
113 }
114 
115 int
116 __libc_mutex_catchall_stub(mutex_t *m)
117 {
118 	/* LINTED deliberate lack of effect */
119 	(void)m;
120 
121 	CHECK_NOT_THREADED();
122 
123 	return (0);
124 }
125 
126 int
127 __libc_mutexattr_settype_stub(mutexattr_t *ma, int type)
128 {
129 	/* LINTED deliberate lack of effect */
130 	(void)ma;
131 	/* LINTED deliberate lack of effect */
132 	(void)type;
133 
134 	return (0);
135 }
136 
137 int
138 __libc_mutexattr_catchall_stub(mutexattr_t *ma)
139 {
140 	/* LINTED deliberate lack of effect */
141 	(void)ma;
142 
143 	CHECK_NOT_THREADED();
144 
145 	return (0);
146 }
147 
148 /* condition variables */
149 
150 int	__libc_cond_init_stub(cond_t *, const condattr_t *);
151 int	__libc_cond_wait_stub(cond_t *, mutex_t *);
152 int	__libc_cond_timedwait_stub(cond_t *, mutex_t *,
153 				   const struct timespec *);
154 int	__libc_cond_catchall_stub(cond_t *);
155 
156 __weak_alias(__libc_cond_init,__libc_cond_init_stub)
157 __weak_alias(__libc_cond_signal,__libc_cond_catchall_stub)
158 __weak_alias(__libc_cond_broadcast,__libc_cond_catchall_stub)
159 __weak_alias(__libc_cond_wait,__libc_cond_wait_stub)
160 __weak_alias(__libc_cond_timedwait,__libc_cond_timedwait_stub)
161 __weak_alias(__libc_cond_destroy,__libc_cond_catchall_stub)
162 
163 int
164 __libc_cond_init_stub(cond_t *c, const condattr_t *a)
165 {
166 	/* LINTED deliberate lack of effect */
167 	(void)c;
168 	/* LINTED deliberate lack of effect */
169 	(void)a;
170 
171 	CHECK_NOT_THREADED();
172 
173 	return (0);
174 }
175 
176 int
177 __libc_cond_wait_stub(cond_t *c, mutex_t *m)
178 {
179 	/* LINTED deliberate lack of effect */
180 	(void)c;
181 	/* LINTED deliberate lack of effect */
182 	(void)m;
183 
184 	CHECK_NOT_THREADED();
185 
186 	return (0);
187 }
188 
189 int
190 __libc_cond_timedwait_stub(cond_t *c, mutex_t *m, const struct timespec *t)
191 {
192 	/* LINTED deliberate lack of effect */
193 	(void)c;
194 	/* LINTED deliberate lack of effect */
195 	(void)m;
196 	/* LINTED deliberate lack of effect */
197 	(void)t;
198 
199 	CHECK_NOT_THREADED();
200 
201 	return (0);
202 }
203 
204 int
205 __libc_cond_catchall_stub(cond_t *c)
206 {
207 	/* LINTED deliberate lack of effect */
208 	(void)c;
209 
210 	CHECK_NOT_THREADED();
211 
212 	return (0);
213 }
214 
215 
216 /* read-write locks */
217 
218 int	__libc_rwlock_init_stub(rwlock_t *, rwlockattr_t *);
219 int	__libc_rwlock_catchall_stub(rwlock_t *);
220 
221 __weak_alias(__libc_rwlock_init,__libc_rwlock_init_stub)
222 __weak_alias(__libc_rwlock_rdlock,__libc_rwlock_catchall_stub)
223 __weak_alias(__libc_rwlock_wrlock,__libc_rwlock_catchall_stub)
224 __weak_alias(__libc_rwlock_tryrdlock,__libc_rwlock_catchall_stub)
225 __weak_alias(__libc_rwlock_trywrlock,__libc_rwlock_catchall_stub)
226 __weak_alias(__libc_rwlock_unlock,__libc_rwlock_catchall_stub)
227 __weak_alias(__libc_rwlock_destroy,__libc_rwlock_catchall_stub)
228 
229 int
230 __libc_rwlock_init_stub(rwlock_t *l, rwlockattr_t *a)
231 {
232 	/* LINTED deliberate lack of effect */
233 	(void)l;
234 	/* LINTED deliberate lack of effect */
235 	(void)a;
236 
237 	CHECK_NOT_THREADED();
238 
239 	return (0);
240 }
241 
242 int
243 __libc_rwlock_catchall_stub(rwlock_t *l)
244 {
245 	/* LINTED deliberate lack of effect */
246 	(void)l;
247 
248 	CHECK_NOT_THREADED();
249 
250 	return (0);
251 }
252 
253 
254 /*
255  * thread-specific data; we need to actually provide a simple TSD
256  * implementation, since some thread-safe libraries want to use it.
257  */
258 
259 #define	TSD_KEYS_MAX	64
260 
261 static struct {
262 	void *tsd_val;
263 	void (*tsd_dtor)(void *);
264 	int tsd_inuse;
265 } __libc_tsd[TSD_KEYS_MAX];
266 static int __libc_tsd_nextkey;
267 
268 int	__libc_thr_keycreate_stub(thread_key_t *, void (*)(void *));
269 int	__libc_thr_setspecific_stub(thread_key_t, const void *);
270 void	*__libc_thr_getspecific_stub(thread_key_t);
271 int	__libc_thr_keydelete_stub(thread_key_t);
272 
273 __weak_alias(__libc_thr_keycreate,__libc_thr_keycreate_stub)
274 __weak_alias(__libc_thr_setspecific,__libc_thr_setspecific_stub)
275 __weak_alias(__libc_thr_getspecific,__libc_thr_getspecific_stub)
276 __weak_alias(__libc_thr_keydelete,__libc_thr_keydelete_stub)
277 
278 int
279 __libc_thr_keycreate_stub(thread_key_t *k, void (*d)(void *))
280 {
281 	int i;
282 
283 	for (i = __libc_tsd_nextkey; i < TSD_KEYS_MAX; i++) {
284 		if (__libc_tsd[i].tsd_inuse == 0)
285 			goto out;
286 	}
287 
288 	for (i = 0; i < __libc_tsd_nextkey; i++) {
289 		if (__libc_tsd[i].tsd_inuse == 0)
290 			goto out;
291 	}
292 
293 	return (EAGAIN);
294 
295  out:
296 	/*
297 	 * XXX We don't actually do anything with the destructor.  We
298 	 * XXX probably should.
299 	 */
300 	__libc_tsd[i].tsd_inuse = 1;
301 	__libc_tsd_nextkey = (i + i) % TSD_KEYS_MAX;
302 	__libc_tsd[i].tsd_dtor = d;
303 	*k = i;
304 
305 	return (0);
306 }
307 
308 int
309 __libc_thr_setspecific_stub(thread_key_t k, const void *v)
310 {
311 
312 	__libc_tsd[k].tsd_val = __UNCONST(v);
313 
314 	return (0);
315 }
316 
317 void *
318 __libc_thr_getspecific_stub(thread_key_t k)
319 {
320 
321 	return (__libc_tsd[k].tsd_val);
322 }
323 
324 int
325 __libc_thr_keydelete_stub(thread_key_t k)
326 {
327 
328 	/*
329 	 * XXX Do not recycle key; see big comment in libpthread.
330 	 */
331 
332 	__libc_tsd[k].tsd_dtor = NULL;
333 
334 	return (0);
335 }
336 
337 
338 /* misc. */
339 
340 int	__libc_thr_once_stub(once_t *, void (*)(void));
341 int	__libc_thr_sigsetmask_stub(int, const sigset_t *, sigset_t *);
342 thr_t	__libc_thr_self_stub(void);
343 int	__libc_thr_yield_stub(void);
344 int	__libc_thr_create_stub(thr_t *, const thrattr_t *,
345 	    void *(*)(void *), void *);
346 void	__libc_thr_exit_stub(void *);
347 int	*__libc_thr_errno_stub(void);
348 int	__libc_thr_setcancelstate_stub(int, int *);
349 int	__libc_thr_equal_stub(pthread_t, pthread_t);
350 unsigned int __libc_thr_curcpu_stub(void);
351 
352 __weak_alias(__libc_thr_once,__libc_thr_once_stub)
353 __weak_alias(__libc_thr_sigsetmask,__libc_thr_sigsetmask_stub)
354 __weak_alias(__libc_thr_self,__libc_thr_self_stub)
355 __weak_alias(__libc_thr_yield,__libc_thr_yield_stub)
356 __weak_alias(__libc_thr_create,__libc_thr_create_stub)
357 __weak_alias(__libc_thr_exit,__libc_thr_exit_stub)
358 __weak_alias(__libc_thr_errno,__libc_thr_errno_stub)
359 __weak_alias(__libc_thr_setcancelstate,__libc_thr_setcancelstate_stub)
360 __weak_alias(__libc_thr_equal,__libc_thr_equal_stub)
361 __weak_alias(__libc_thr_curcpu,__libc_thr_curcpu_stub)
362 
363 
364 int
365 __libc_thr_once_stub(once_t *o, void (*r)(void))
366 {
367 
368 	/* XXX Knowledge of libpthread types. */
369 
370 	if (o->pto_done == 0) {
371 		(*r)();
372 		o->pto_done = 1;
373 	}
374 
375 	return (0);
376 }
377 
378 int
379 __libc_thr_sigsetmask_stub(int h, const sigset_t *s, sigset_t *o)
380 {
381 
382 	CHECK_NOT_THREADED();
383 
384 	return sigprocmask(h, s, o);
385 }
386 
387 thr_t
388 __libc_thr_self_stub(void)
389 {
390 
391 	return ((thr_t) -1);
392 }
393 
394 int
395 __libc_thr_yield_stub(void)
396 {
397 
398 	/* Nothing to do. */
399 	return (0);
400 }
401 
402 int
403 __libc_thr_create_stub(thr_t *tp, const thrattr_t *ta,
404     void *(*f)(void *), void *a)
405 {
406 	/* LINTED deliberate lack of effect */
407 	(void)tp;
408 	/* LINTED deliberate lack of effect */
409 	(void)ta;
410 	/* LINTED deliberate lack of effect */
411 	(void)f;
412 	/* LINTED deliberate lack of effect */
413 	(void)a;
414 
415 	DIE();
416 
417 	return (EOPNOTSUPP);
418 }
419 
420 void
421 __libc_thr_exit_stub(void *v)
422 {
423 	/* LINTED deliberate lack of effect */
424 	(void)v;
425 	exit(0);
426 }
427 
428 int
429 __libc_thr_setcancelstate_stub(int new, int *old)
430 {
431 	/* LINTED deliberate lack of effect */
432 	(void)new;
433 
434 	/* LINTED deliberate lack of effect */
435 	(void)old;
436 
437 	CHECK_NOT_THREADED();
438 
439 	return (0);
440 }
441 
442 int
443 __libc_thr_equal_stub(pthread_t t1, pthread_t t2)
444 {
445 
446 	/* assert that t1=t2=pthread_self() */
447 	return (t1 == t2);
448 }
449 
450 int *
451 __libc_thr_errno_stub(void)
452 {
453 
454 	DIE();
455 
456 	return (NULL);
457 }
458 
459 unsigned int
460 __libc_thr_curcpu_stub(void)
461 {
462 
463 	return (0);
464 }
465 
466 #endif /* _REENTRANT */
467