lib/libc/thread-stub/thread-stub.c

   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 */