scheduler/pthread.c

   1 /*
   2  * pthread emulation for re-entrant libcs
   3  *
   4  * We can't use pthreads directly, so why not let libcs
   5  * that want pthreads use Wine's own threading instead...
   6  *
   7  * Copyright 1999 Ove Kåven
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24 #include "config.h"
  25 #define _GNU_SOURCE /* we may need to override some GNU extensions */
  26
  27 #include <assert.h>
  28 #include <errno.h>
  29 #include <stdlib.h>
  30 #include <unistd.h>
  31 #include <string.h>
  32
  33 #include "winbase.h"
  34 #include "thread.h"
  35 #include "ntddk.h"
  36
  37 static int init_done;
  38
  39 void PTHREAD_init_done(void)
  40 {
  41     init_done = 1;
  42 }
  43
  44 /* Currently this probably works only for glibc2,
  45  * which checks for the presence of double-underscore-prepended
  46  * pthread primitives, and use them if available.
  47  * If they are not available, the libc defaults to
  48  * non-threadsafe operation (not good). */
  49
  50 #if defined(__GLIBC__)
  51 #include <pthread.h>
  52 #include <signal.h>
  53
  54 #ifdef NEED_UNDERSCORE_PREFIX
  55 # define PREFIX "_"
  56 #else
  57 # define PREFIX
  58 #endif
  59
  60 #define PSTR(str) PREFIX #str
  61
  62 /* adapt as necessary (a construct like this is used in glibc sources) */
  63 #define strong_alias(orig, alias) \
  64  asm(".globl " PSTR(alias) "\n" \
  65      "\t.set " PSTR(alias) "," PSTR(orig))
  66
  67 /* strong_alias does not work on external symbols (.o format limitation?),
  68  * so for those, we need to use the pogo stick */
  69 #if defined(__i386__) && !defined(__PIC__)
  70 /* FIXME: PIC */
  71 #define jump_alias(orig, alias) \
  72  asm(".globl " PSTR(alias) "\n" \
  73      "\t.type " PSTR(alias) ",@function\n" \
  74      PSTR(alias) ":\n" \
  75      "\tjmp " PSTR(orig))
  76 #endif
  77
  78 /* get necessary libc symbols */
  79 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 1) && defined(HAVE___LIBC_FORK)
  80 #define LIBC_FORK __libc_fork
  81 #define PTHREAD_FORK __fork
  82 #define ALIAS_FORK
  83 #else
  84 #define LIBC_FORK __fork
  85 #define PTHREAD_FORK fork
  86 #endif
  87 extern pid_t LIBC_FORK(void);
  88
  89 #define LIBC_SIGACTION __sigaction
  90 extern int LIBC_SIGACTION(int signum,
  91                          const struct sigaction *act,
  92                          struct sigaction *oldact);
  93
  94 /* NOTE: This is a truly extremely incredibly ugly hack!
  95  * But it does seem to work... */
  96
  97 /* assume that pthread_mutex_t has room for at least one pointer,
  98  * and hope that the users of pthread_mutex_t considers it opaque
  99  * (never checks what's in it)
 100  * also: assume that static initializer sets pointer to NULL
 101  */
 102 typedef struct {
 103   CRITICAL_SECTION *critsect;
 104 } *wine_mutex;
 105
 106 /* see wine_mutex above for comments */
 107 typedef struct {
 108   RTL_RWLOCK *lock;
 109 } *wine_rwlock;
 110
 111 typedef struct _wine_cleanup {
 112   void (*routine)(void *);
 113   void *arg;
 114 } *wine_cleanup;
 115
 116 typedef const void *key_data;
 117
 118 #define FIRST_KEY 0
 119 #define MAX_KEYS 16 /* libc6 doesn't use that many, but... */
 120
 121 #define P_OUTPUT(stuff) write(2,stuff,strlen(stuff))
 122
 123 void __pthread_initialize(void)
 124 {
 125 }
 126
 127 int __pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
 128 {
 129   static pthread_once_t the_once = PTHREAD_ONCE_INIT;
 130   LONG once_now = *(LONG *)&the_once;
 131
 132   if (InterlockedCompareExchange((LONG*)once_control, once_now+1, once_now) == once_now)
 133     (*init_routine)();
 134   return 0;
 135 }
 136 strong_alias(__pthread_once, pthread_once);
 137
 138 void __pthread_kill_other_threads_np(void)
 139 {
 140     /* we don't need to do anything here */
 141 }
 142 strong_alias(__pthread_kill_other_threads_np, pthread_kill_other_threads_np);
 143
 144 /***** atfork *****/
 145
 146 #define MAX_ATFORK 8  /* libc doesn't need that many anyway */
 147
 148 static CRITICAL_SECTION atfork_section = CRITICAL_SECTION_INIT("atfork_section");
 149 typedef void (*atfork_handler)();
 150 static atfork_handler atfork_prepare[MAX_ATFORK];
 151 static atfork_handler atfork_parent[MAX_ATFORK];
 152 static atfork_handler atfork_child[MAX_ATFORK];
 153 static int atfork_count;
 154
 155 int __pthread_atfork(void (*prepare)(void),
 156                      void (*parent)(void),
 157                      void (*child)(void))
 158 {
 159     if (init_done) EnterCriticalSection( &atfork_section );
 160     assert( atfork_count < MAX_ATFORK );
 161     atfork_prepare[atfork_count] = prepare;
 162     atfork_parent[atfork_count] = parent;
 163     atfork_child[atfork_count] = child;
 164     atfork_count++;
 165     if (init_done) LeaveCriticalSection( &atfork_section );
 166     return 0;
 167 }
 168 strong_alias(__pthread_atfork, pthread_atfork);
 169
 170 pid_t PTHREAD_FORK(void)
 171 {
 172     pid_t pid;
 173     int i;
 174
 175     EnterCriticalSection( &atfork_section );
 176     /* prepare handlers are called in reverse insertion order */
 177     for (i = atfork_count - 1; i >= 0; i--) if (atfork_prepare[i]) atfork_prepare[i]();
 178     if (!(pid = LIBC_FORK()))
 179     {
 180         InitializeCriticalSection( &atfork_section );
 181         for (i = 0; i < atfork_count; i++) if (atfork_child[i]) atfork_child[i]();
 182     }
 183     else
 184     {
 185         for (i = 0; i < atfork_count; i++) if (atfork_parent[i]) atfork_parent[i]();
 186         LeaveCriticalSection( &atfork_section );
 187     }
 188     return pid;
 189 }
 190 #ifdef ALIAS_FORK
 191 strong_alias(PTHREAD_FORK, fork);
 192 #endif
 193
 194 /***** MUTEXES *****/
 195
 196 int __pthread_mutex_init(pthread_mutex_t *mutex,
 197                         const pthread_mutexattr_t *mutexattr)
 198 {
 199   /* glibc has a tendency to initialize mutexes very often, even
 200      in situations where they are not really used later on.
 201
 202      As for us, initializing a mutex is very expensive, we postpone
 203      the real initialization until the time the mutex is first used. */
 204
 205   ((wine_mutex)mutex)->critsect = NULL;
 206   return 0;
 207 }
 208 strong_alias(__pthread_mutex_init, pthread_mutex_init);
 209
 210 static void mutex_real_init( pthread_mutex_t *mutex )
 211 {
 212   CRITICAL_SECTION *critsect = HeapAlloc(GetProcessHeap(), 0, sizeof(CRITICAL_SECTION));
 213   InitializeCriticalSection(critsect);
 214
 215   if (InterlockedCompareExchangePointer((void**)&(((wine_mutex)mutex)->critsect),critsect,NULL) != NULL) {
 216     /* too late, some other thread already did it */
 217     DeleteCriticalSection(critsect);
 218     HeapFree(GetProcessHeap(), 0, critsect);
 219   }
 220 }
 221
 222 int __pthread_mutex_lock(pthread_mutex_t *mutex)
 223 {
 224   if (!init_done) return 0;
 225   if (!((wine_mutex)mutex)->critsect)
 226     mutex_real_init( mutex );
 227
 228   EnterCriticalSection(((wine_mutex)mutex)->critsect);
 229   return 0;
 230 }
 231 strong_alias(__pthread_mutex_lock, pthread_mutex_lock);
 232
 233 int __pthread_mutex_trylock(pthread_mutex_t *mutex)
 234 {
 235   if (!init_done) return 0;
 236   if (!((wine_mutex)mutex)->critsect)
 237     mutex_real_init( mutex );
 238
 239   if (!TryEnterCriticalSection(((wine_mutex)mutex)->critsect)) {
 240     errno = EBUSY;
 241     return -1;
 242   }
 243   return 0;
 244 }
 245 strong_alias(__pthread_mutex_trylock, pthread_mutex_trylock);
 246
 247 int __pthread_mutex_unlock(pthread_mutex_t *mutex)
 248 {
 249   if (!((wine_mutex)mutex)->critsect) return 0;
 250   LeaveCriticalSection(((wine_mutex)mutex)->critsect);
 251   return 0;
 252 }
 253 strong_alias(__pthread_mutex_unlock, pthread_mutex_unlock);
 254
 255 int __pthread_mutex_destroy(pthread_mutex_t *mutex)
 256 {
 257   if (!((wine_mutex)mutex)->critsect) return 0;
 258   if (((wine_mutex)mutex)->critsect->RecursionCount) {
 259 #if 0 /* there seems to be a bug in libc6 that makes this a bad idea */
 260     return EBUSY;
 261 #else
 262     while (((wine_mutex)mutex)->critsect->RecursionCount)
 263       LeaveCriticalSection(((wine_mutex)mutex)->critsect);
 264 #endif
 265   }
 266   DeleteCriticalSection(((wine_mutex)mutex)->critsect);
 267   HeapFree(GetProcessHeap(), 0, ((wine_mutex)mutex)->critsect);
 268   return 0;
 269 }
 270 strong_alias(__pthread_mutex_destroy, pthread_mutex_destroy);
 271
 272
 273 /***** MUTEX ATTRIBUTES *****/
 274 /* just dummies, since critical sections are always recursive */
 275
 276 int __pthread_mutexattr_init(pthread_mutexattr_t *attr)
 277 {
 278   return 0;
 279 }
 280 strong_alias(__pthread_mutexattr_init, pthread_mutexattr_init);
 281
 282 int __pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
 283 {
 284   return 0;
 285 }
 286 strong_alias(__pthread_mutexattr_destroy, pthread_mutexattr_destroy);
 287
 288 int __pthread_mutexattr_setkind_np(pthread_mutexattr_t *attr, int kind)
 289 {
 290   return 0;
 291 }
 292 strong_alias(__pthread_mutexattr_setkind_np, pthread_mutexattr_setkind_np);
 293
 294 int __pthread_mutexattr_getkind_np(pthread_mutexattr_t *attr, int *kind)
 295 {
 296   *kind = PTHREAD_MUTEX_RECURSIVE_NP;
 297   return 0;
 298 }
 299 strong_alias(__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np);
 300
 301 int __pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind)
 302 {
 303   return 0;
 304 }
 305 strong_alias(__pthread_mutexattr_settype, pthread_mutexattr_settype);
 306
 307 int __pthread_mutexattr_gettype(pthread_mutexattr_t *attr, int *kind)
 308 {
 309   *kind = PTHREAD_MUTEX_RECURSIVE_NP;
 310   return 0;
 311 }
 312 strong_alias(__pthread_mutexattr_gettype, pthread_mutexattr_gettype);
 313
 314
 315 /***** THREAD-SPECIFIC VARIABLES (KEYS) *****/
 316
 317 int __pthread_key_create(pthread_key_t *key, void (*destr_function)(void *))
 318 {
 319   static LONG keycnt = FIRST_KEY;
 320   *key = InterlockedExchangeAdd(&keycnt, 1);
 321   return 0;
 322 }
 323 strong_alias(__pthread_key_create, pthread_key_create);
 324
 325 int __pthread_key_delete(pthread_key_t key)
 326 {
 327   return 0;
 328 }
 329 strong_alias(__pthread_key_delete, pthread_key_delete);
 330
 331 int __pthread_setspecific(pthread_key_t key, const void *pointer)
 332 {
 333   TEB *teb = NtCurrentTeb();
 334   if (!teb->pthread_data) {
 335     teb->pthread_data = calloc(MAX_KEYS,sizeof(key_data));
 336   }
 337   ((key_data*)(teb->pthread_data))[key] = pointer;
 338   return 0;
 339 }
 340 strong_alias(__pthread_setspecific, pthread_setspecific);
 341
 342 void *__pthread_getspecific(pthread_key_t key)
 343 {
 344   TEB *teb = NtCurrentTeb();
 345   if (!teb) return NULL;
 346   if (!teb->pthread_data) return NULL;
 347   return (void *)(((key_data*)(teb->pthread_data))[key]);
 348 }
 349 strong_alias(__pthread_getspecific, pthread_getspecific);
 350
 351
 352 /***** "EXCEPTION" FRAMES *****/
 353 /* not implemented right now */
 354
 355 void _pthread_cleanup_push(struct _pthread_cleanup_buffer *buffer, void (*routine)(void *), void *arg)
 356 {
 357   ((wine_cleanup)buffer)->routine = routine;
 358   ((wine_cleanup)buffer)->arg = arg;
 359 }
 360
 361 void _pthread_cleanup_pop(struct _pthread_cleanup_buffer *buffer, int execute)
 362 {
 363   if (execute) (*(((wine_cleanup)buffer)->routine))(((wine_cleanup)buffer)->arg);
 364 }
 365
 366 void _pthread_cleanup_push_defer(struct _pthread_cleanup_buffer *buffer, void (*routine)(void *), void *arg)
 367 {
 368   _pthread_cleanup_push(buffer, routine, arg);
 369 }
 370
 371 void _pthread_cleanup_pop_restore(struct _pthread_cleanup_buffer *buffer, int execute)
 372 {
 373   _pthread_cleanup_pop(buffer, execute);
 374 }
 375
 376
 377 /***** CONDITIONS *****/
 378 /* not implemented right now */
 379
 380 int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *cond_attr)
 381 {
 382   P_OUTPUT("FIXME:pthread_cond_init\n");
 383   return 0;
 384 }
 385
 386 int pthread_cond_destroy(pthread_cond_t *cond)
 387 {
 388   P_OUTPUT("FIXME:pthread_cond_destroy\n");
 389   return 0;
 390 }
 391
 392 int pthread_cond_signal(pthread_cond_t *cond)
 393 {
 394   P_OUTPUT("FIXME:pthread_cond_signal\n");
 395   return 0;
 396 }
 397
 398 int pthread_cond_broadcast(pthread_cond_t *cond)
 399 {
 400   P_OUTPUT("FIXME:pthread_cond_broadcast\n");
 401   return 0;
 402 }
 403
 404 int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
 405 {
 406   P_OUTPUT("FIXME:pthread_cond_wait\n");
 407   return 0;
 408 }
 409
 410 int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, const struct timespec *abstime)
 411 {
 412   P_OUTPUT("FIXME:pthread_cond_timedwait\n");
 413   return 0;
 414 }
 415
 416 /**** CONDITION ATTRIBUTES *****/
 417 /* not implemented right now */
 418
 419 int pthread_condattr_init(pthread_condattr_t *attr)
 420 {
 421   return 0;
 422 }
 423
 424 int pthread_condattr_destroy(pthread_condattr_t *attr)
 425 {
 426   return 0;
 427 }
 428
 429 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 2)
 430 /***** READ-WRITE LOCKS *****/
 431
 432 static void rwlock_real_init(pthread_rwlock_t *rwlock)
 433 {
 434   RTL_RWLOCK *lock = HeapAlloc(GetProcessHeap(), 0, sizeof(RTL_RWLOCK));
 435   RtlInitializeResource(lock);
 436
 437   if (InterlockedCompareExchangePointer((void**)&(((wine_rwlock)rwlock)->lock),lock,NULL) != NULL) {
 438     /* too late, some other thread already did it */
 439     RtlDeleteResource(lock);
 440     HeapFree(GetProcessHeap(), 0, lock);
 441   }
 442 }
 443
 444 int __pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *rwlock_attr)
 445 {
 446   ((wine_rwlock)rwlock)->lock = NULL;
 447   return 0;
 448 }
 449 strong_alias(__pthread_rwlock_init, pthread_rwlock_init);
 450
 451 int __pthread_rwlock_destroy(pthread_rwlock_t *rwlock)
 452 {
 453   if (!((wine_rwlock)rwlock)->lock) return 0;
 454   RtlDeleteResource(((wine_rwlock)rwlock)->lock);
 455   HeapFree(GetProcessHeap(), 0, ((wine_rwlock)rwlock)->lock);
 456   return 0;
 457 }
 458 strong_alias(__pthread_rwlock_destroy, pthread_rwlock_destroy);
 459
 460 int __pthread_rwlock_rdlock(pthread_rwlock_t *rwlock)
 461 {
 462   if (!init_done) return 0;
 463   if (!((wine_rwlock)rwlock)->lock)
 464     rwlock_real_init( rwlock );
 465
 466   while(TRUE)
 467     if (RtlAcquireResourceShared(((wine_rwlock)rwlock)->lock, TRUE))
 468       return 0;
 469 }
 470 strong_alias(__pthread_rwlock_rdlock, pthread_rwlock_rdlock);
 471
 472 int __pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock)
 473 {
 474   if (!init_done) return 0;
 475   if (!((wine_rwlock)rwlock)->lock)
 476     rwlock_real_init( rwlock );
 477
 478   if (!RtlAcquireResourceShared(((wine_rwlock)rwlock)->lock, FALSE)) {
 479     errno = EBUSY;
 480     return -1;
 481   }
 482   return 0;
 483 }
 484 strong_alias(__pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock);
 485
 486 int __pthread_rwlock_wrlock(pthread_rwlock_t *rwlock)
 487 {
 488   if (!init_done) return 0;
 489   if (!((wine_rwlock)rwlock)->lock)
 490     rwlock_real_init( rwlock );
 491
 492   while(TRUE)
 493     if (RtlAcquireResourceExclusive(((wine_rwlock)rwlock)->lock, TRUE))
 494       return 0;
 495 }
 496 strong_alias(__pthread_rwlock_wrlock, pthread_rwlock_wrlock);
 497
 498 int __pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)
 499 {
 500   if (!init_done) return 0;
 501   if (!((wine_rwlock)rwlock)->lock)
 502     rwlock_real_init( rwlock );
 503
 504   if (!RtlAcquireResourceExclusive(((wine_rwlock)rwlock)->lock, FALSE)) {
 505     errno = EBUSY;
 506     return -1;
 507   }
 508   return 0;
 509 }
 510 strong_alias(__pthread_rwlock_trywrlock, pthread_rwlock_trywrlock);
 511
 512 int __pthread_rwlock_unlock(pthread_rwlock_t *rwlock)
 513 {
 514   if (!((wine_rwlock)rwlock)->lock) return 0;
 515   RtlReleaseResource( ((wine_rwlock)rwlock)->lock );
 516   return 0;
 517 }
 518 strong_alias(__pthread_rwlock_unlock, pthread_rwlock_unlock);
 519
 520 /**** READ-WRITE LOCK ATTRIBUTES *****/
 521 /* not implemented right now */
 522
 523 int pthread_rwlockattr_init(pthread_rwlockattr_t *attr)
 524 {
 525   return 0;
 526 }
 527
 528 int __pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr)
 529 {
 530   return 0;
 531 }
 532 strong_alias(__pthread_rwlockattr_destroy, pthread_rwlockattr_destroy);
 533
 534 int pthread_rwlockattr_getkind_np(const pthread_rwlockattr_t *attr, int *pref)
 535 {
 536   *pref = 0;
 537   return 0;
 538 }
 539
 540 int pthread_rwlockattr_setkind_np(pthread_rwlockattr_t *attr, int pref)
 541 {
 542   return 0;
 543 }
 544 #endif /* glibc 2.2 */
 545
 546 /***** MISC *****/
 547
 548 pthread_t pthread_self(void)
 549 {
 550   return (pthread_t)GetCurrentThreadId();
 551 }
 552
 553 int pthread_equal(pthread_t thread1, pthread_t thread2)
 554 {
 555   return (DWORD)thread1 == (DWORD)thread2;
 556 }
 557
 558 void pthread_exit(void *retval)
 559 {
 560   /* FIXME: pthread cleanup */
 561   ExitThread((DWORD)retval);
 562 }
 563
 564 int pthread_setcanceltype(int type, int *oldtype)
 565 {
 566   if (oldtype) *oldtype = PTHREAD_CANCEL_ASYNCHRONOUS;
 567   return 0;
 568 }
 569
 570 /***** ANTI-OVERRIDES *****/
 571 /* pthreads tries to override these, point them back to libc */
 572
 573 #ifdef jump_alias
 574 jump_alias(LIBC_SIGACTION, sigaction);
 575 #else
 576 int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
 577 {
 578   return LIBC_SIGACTION(signum, act, oldact);
 579 }
 580 #endif
 581
 582 #endif /* __GLIBC__ */