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