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