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