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