1 /* $NetBSD: thread-stub.c,v 1.34 2025/10/06 13:12:29 riastradh 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 1.34 2025/10/06 13:12:29 riastradh 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 #include "tsd.h" 49 50 #include <errno.h> 51 #include <signal.h> 52 #include <stdlib.h> 53 #include <unistd.h> 54 55 extern int __isthreaded; 56 57 #define DIE() (void)raise(SIGABRT) 58 59 #define CHECK_NOT_THREADED_ALWAYS() \ 60 do { \ 61 if (__isthreaded) \ 62 DIE(); \ 63 } while (0) 64 65 #if 1 66 #define CHECK_NOT_THREADED() CHECK_NOT_THREADED_ALWAYS() 67 #else 68 #define CHECK_NOT_THREADED() /* nothing */ 69 #endif 70 71 /* 72 * These aliases are probably not necessary but have been there 73 * historically, probably by mistake. 74 */ 75 __weak_alias(pthread_join, __libc_thr_join) 76 __weak_alias(pthread_detach, __libc_thr_detach) 77 78 /* 79 * These aliases appear to have been an accident -- nothing has ever 80 * exposed them in a .h file, and they have probably never been used. 81 */ 82 __strong_alias(__libc_pthread_join, __libc_thr_join) 83 __strong_alias(__libc_pthread_detach, __libc_thr_detach) 84 85 /* 86 * These aliases are exposed by pthread.h and overridden by libpthread. 87 * This way libraries can have calls to pthread_create/join/detach 88 * without linking against libpthread, but they will fail at runtime in 89 * applications not linked against libpthread. (Libraries linked 90 * against libpthread themselves, of course, will work, and carry the 91 * dependency to the application.) 92 */ 93 __weak_alias(__libc_thr_join, __libc_thr_join_stub) 94 __weak_alias(__libc_thr_detach, __libc_thr_detach_stub) 95 96 int 97 __libc_thr_join_stub(pthread_t thread, void **valptr) 98 { 99 100 if (thread == pthread_self()) 101 return EDEADLK; 102 return ESRCH; 103 } 104 105 int 106 __libc_thr_detach_stub(pthread_t thread) 107 { 108 109 if (thread == pthread_self()) 110 return 0; 111 return ESRCH; 112 } 113 114 __weak_alias(pthread_setname_np, __libc_mutex_catchall_stub) 115 __weak_alias(pthread_setaffinity_np, __libc_mutex_catchall_stub) 116 117 /* thread creation attributes */ 118 119 __weak_alias(__libc_thr_attr_init, __libc_mutex_catchall_stub) 120 __weak_alias(__libc_thr_attr_setdetachstate, __libc_mutex_catchall_stub) 121 __weak_alias(__libc_thr_attr_destroy, __libc_mutex_catchall_stub) 122 123 /* mutexes */ 124 125 int __libc_mutex_catchall_stub(mutex_t *); 126 127 __weak_alias(__libc_mutex_init,__libc_mutex_init_stub) 128 __weak_alias(__libc_mutex_lock,__libc_mutex_catchall_stub) 129 __weak_alias(__libc_mutex_trylock,__libc_mutex_catchall_stub) 130 __weak_alias(__libc_mutex_unlock,__libc_mutex_catchall_stub) 131 __weak_alias(__libc_mutex_destroy,__libc_mutex_catchall_stub) 132 133 __strong_alias(__libc_mutex_lock_stub,__libc_mutex_catchall_stub) 134 __strong_alias(__libc_mutex_trylock_stub,__libc_mutex_catchall_stub) 135 __strong_alias(__libc_mutex_unlock_stub,__libc_mutex_catchall_stub) 136 __strong_alias(__libc_mutex_destroy_stub,__libc_mutex_catchall_stub) 137 138 int __libc_mutexattr_catchall_stub(mutexattr_t *); 139 140 __weak_alias(__libc_mutexattr_init,__libc_mutexattr_catchall_stub) 141 __weak_alias(__libc_mutexattr_destroy,__libc_mutexattr_catchall_stub) 142 __weak_alias(__libc_mutexattr_settype,__libc_mutexattr_settype_stub) 143 144 __strong_alias(__libc_mutexattr_init_stub,__libc_mutexattr_catchall_stub) 145 __strong_alias(__libc_mutexattr_destroy_stub,__libc_mutexattr_catchall_stub) 146 147 int 148 __libc_mutex_init_stub(mutex_t *m, const mutexattr_t *a) 149 { 150 /* LINTED deliberate lack of effect */ 151 (void)m; 152 /* LINTED deliberate lack of effect */ 153 (void)a; 154 155 CHECK_NOT_THREADED(); 156 157 return (0); 158 } 159 160 int 161 __libc_mutex_catchall_stub(mutex_t *m) 162 { 163 /* LINTED deliberate lack of effect */ 164 (void)m; 165 166 CHECK_NOT_THREADED(); 167 168 return (0); 169 } 170 171 int 172 __libc_mutexattr_settype_stub(mutexattr_t *ma, int type) 173 { 174 /* LINTED deliberate lack of effect */ 175 (void)ma; 176 /* LINTED deliberate lack of effect */ 177 (void)type; 178 179 CHECK_NOT_THREADED(); 180 181 return (0); 182 } 183 184 int 185 __libc_mutexattr_catchall_stub(mutexattr_t *ma) 186 { 187 /* LINTED deliberate lack of effect */ 188 (void)ma; 189 190 CHECK_NOT_THREADED(); 191 192 return (0); 193 } 194 195 /* condition variables */ 196 197 int __libc_cond_catchall_stub(cond_t *); 198 199 __weak_alias(__libc_cond_init,__libc_cond_init_stub) 200 __weak_alias(__libc_cond_signal,__libc_cond_catchall_stub) 201 __weak_alias(__libc_cond_broadcast,__libc_cond_catchall_stub) 202 __weak_alias(__libc_cond_wait,__libc_cond_catchall_stub) 203 __weak_alias(__libc_cond_timedwait,__libc_cond_timedwait_stub) 204 __weak_alias(__libc_cond_destroy,__libc_cond_catchall_stub) 205 206 __strong_alias(__libc_cond_signal_stub,__libc_cond_catchall_stub) 207 __strong_alias(__libc_cond_broadcast_stub,__libc_cond_catchall_stub) 208 __strong_alias(__libc_cond_destroy_stub,__libc_cond_catchall_stub) 209 210 int 211 __libc_cond_init_stub(cond_t *c, const condattr_t *a) 212 { 213 /* LINTED deliberate lack of effect */ 214 (void)c; 215 /* LINTED deliberate lack of effect */ 216 (void)a; 217 218 CHECK_NOT_THREADED(); 219 220 return (0); 221 } 222 223 int 224 __libc_cond_wait_stub(cond_t *c, mutex_t *m) 225 { 226 /* LINTED deliberate lack of effect */ 227 (void)c; 228 /* LINTED deliberate lack of effect */ 229 (void)m; 230 231 CHECK_NOT_THREADED(); 232 233 return (0); 234 } 235 236 int 237 __libc_cond_timedwait_stub(cond_t *c, mutex_t *m, const struct timespec *t) 238 { 239 /* LINTED deliberate lack of effect */ 240 (void)c; 241 /* LINTED deliberate lack of effect */ 242 (void)m; 243 /* LINTED deliberate lack of effect */ 244 (void)t; 245 246 CHECK_NOT_THREADED(); 247 248 return (0); 249 } 250 251 int 252 __libc_cond_catchall_stub(cond_t *c) 253 { 254 /* LINTED deliberate lack of effect */ 255 (void)c; 256 257 CHECK_NOT_THREADED(); 258 259 return (0); 260 } 261 262 263 /* read-write locks */ 264 265 int __libc_rwlock_catchall_stub(rwlock_t *); 266 267 __weak_alias(__libc_rwlock_init,__libc_rwlock_init_stub) 268 __weak_alias(__libc_rwlock_rdlock,__libc_rwlock_catchall_stub) 269 __weak_alias(__libc_rwlock_wrlock,__libc_rwlock_catchall_stub) 270 __weak_alias(__libc_rwlock_tryrdlock,__libc_rwlock_catchall_stub) 271 __weak_alias(__libc_rwlock_trywrlock,__libc_rwlock_catchall_stub) 272 __weak_alias(__libc_rwlock_unlock,__libc_rwlock_catchall_stub) 273 __weak_alias(__libc_rwlock_destroy,__libc_rwlock_catchall_stub) 274 275 __strong_alias(__libc_rwlock_rdlock_stub,__libc_rwlock_catchall_stub) 276 __strong_alias(__libc_rwlock_wrlock_stub,__libc_rwlock_catchall_stub) 277 __strong_alias(__libc_rwlock_tryrdlock_stub,__libc_rwlock_catchall_stub) 278 __strong_alias(__libc_rwlock_trywrlock_stub,__libc_rwlock_catchall_stub) 279 __strong_alias(__libc_rwlock_unlock_stub,__libc_rwlock_catchall_stub) 280 __strong_alias(__libc_rwlock_destroy_stub,__libc_rwlock_catchall_stub) 281 282 283 int 284 __libc_rwlock_init_stub(rwlock_t *l, const rwlockattr_t *a) 285 { 286 /* LINTED deliberate lack of effect */ 287 (void)l; 288 /* LINTED deliberate lack of effect */ 289 (void)a; 290 291 CHECK_NOT_THREADED(); 292 293 return (0); 294 } 295 296 int 297 __libc_rwlock_catchall_stub(rwlock_t *l) 298 { 299 /* LINTED deliberate lack of effect */ 300 (void)l; 301 302 CHECK_NOT_THREADED(); 303 304 return (0); 305 } 306 307 308 /* 309 * thread-specific data; we need to actually provide a simple TSD 310 * implementation, since some thread-safe libraries want to use it. 311 */ 312 313 struct __libc_tsd __libc_tsd[TSD_KEYS_MAX]; 314 static int __libc_tsd_nextkey; 315 316 __weak_alias(__libc_thr_keycreate,__libc_thr_keycreate_stub) 317 __weak_alias(__libc_thr_setspecific,__libc_thr_setspecific_stub) 318 __weak_alias(__libc_thr_getspecific,__libc_thr_getspecific_stub) 319 __weak_alias(__libc_thr_keydelete,__libc_thr_keydelete_stub) 320 321 int 322 __libc_thr_keycreate_stub(thread_key_t *k, void (*d)(void *)) 323 { 324 int i; 325 326 for (i = __libc_tsd_nextkey; i < TSD_KEYS_MAX; i++) { 327 if (__libc_tsd[i].tsd_inuse == 0) 328 goto out; 329 } 330 331 for (i = 0; i < __libc_tsd_nextkey; i++) { 332 if (__libc_tsd[i].tsd_inuse == 0) 333 goto out; 334 } 335 336 return (EAGAIN); 337 338 out: 339 /* 340 * XXX We don't actually do anything with the destructor. We 341 * XXX probably should. 342 */ 343 __libc_tsd[i].tsd_inuse = 1; 344 __libc_tsd_nextkey = (i + i) % TSD_KEYS_MAX; 345 __libc_tsd[i].tsd_dtor = d; 346 *k = i; 347 348 return (0); 349 } 350 351 int 352 __libc_thr_setspecific_stub(thread_key_t k, const void *v) 353 { 354 355 __libc_tsd[k].tsd_val = __UNCONST(v); 356 357 return (0); 358 } 359 360 void * 361 __libc_thr_getspecific_stub(thread_key_t k) 362 { 363 364 return (__libc_tsd[k].tsd_val); 365 } 366 367 int 368 __libc_thr_keydelete_stub(thread_key_t k) 369 { 370 371 /* 372 * XXX Do not recycle key; see big comment in libpthread. 373 */ 374 375 __libc_tsd[k].tsd_dtor = NULL; 376 377 return (0); 378 } 379 380 381 /* misc. */ 382 383 __weak_alias(__libc_thr_once,__libc_thr_once_stub) 384 __weak_alias(__libc_thr_sigsetmask,__libc_thr_sigsetmask_stub) 385 __weak_alias(__libc_thr_self,__libc_thr_self_stub) 386 __weak_alias(__libc_thr_yield,__libc_thr_yield_stub) 387 __weak_alias(__libc_thr_create,__libc_thr_create_stub) 388 __weak_alias(__libc_thr_exit,__libc_thr_exit_stub) 389 __weak_alias(__libc_thr_setcancelstate,__libc_thr_setcancelstate_stub) 390 __weak_alias(__libc_thr_equal,__libc_thr_equal_stub) 391 __weak_alias(__libc_thr_curcpu,__libc_thr_curcpu_stub) 392 393 394 int 395 __libc_thr_once_stub(once_t *o, void (*r)(void)) 396 { 397 398 /* XXX Knowledge of libpthread types. */ 399 400 if (o->pto_done == 0) { 401 (*r)(); 402 o->pto_done = 1; 403 } 404 405 return (0); 406 } 407 408 int 409 __libc_thr_sigsetmask_stub(int h, const sigset_t *s, sigset_t *o) 410 { 411 412 CHECK_NOT_THREADED(); 413 414 if (sigprocmask(h, s, o)) 415 return errno; 416 return 0; 417 } 418 419 thr_t 420 __libc_thr_self_stub(void) 421 { 422 423 return ((thr_t) -1); 424 } 425 426 /* This is the strong symbol generated for sched_yield(2) via WSYSCALL() */ 427 int _sys_sched_yield(void); 428 429 int 430 __libc_thr_yield_stub(void) 431 { 432 return _sys_sched_yield(); 433 } 434 435 int 436 __libc_thr_create_stub(thr_t *tp, const thrattr_t *ta, 437 void *(*f)(void *), void *a) 438 { 439 /* LINTED deliberate lack of effect */ 440 (void)tp; 441 /* LINTED deliberate lack of effect */ 442 (void)ta; 443 /* LINTED deliberate lack of effect */ 444 (void)f; 445 /* LINTED deliberate lack of effect */ 446 (void)a; 447 448 CHECK_NOT_THREADED(); 449 450 return EOPNOTSUPP; 451 } 452 453 __dead void 454 __libc_thr_exit_stub(void *v) 455 { 456 /* LINTED deliberate lack of effect */ 457 (void)v; 458 exit(0); 459 } 460 461 int 462 __libc_thr_setcancelstate_stub(int new, int *old) 463 { 464 /* LINTED deliberate lack of effect */ 465 (void)new; 466 467 /* LINTED deliberate lack of effect */ 468 (void)old; 469 470 CHECK_NOT_THREADED(); 471 472 return (0); 473 } 474 475 int 476 __libc_thr_equal_stub(pthread_t t1, pthread_t t2) 477 { 478 479 /* assert that t1=t2=pthread_self() */ 480 return (t1 == t2); 481 } 482 483 unsigned int 484 __libc_thr_curcpu_stub(void) 485 { 486 487 return (0); 488 } 489 490 #endif /* _REENTRANT */ 491
Indexes created Thu Oct 16 14:10:15 GMT 2025