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 #include "wine/port.h"
  26
  27 #define _GNU_SOURCE /* we may need to override some GNU extensions */
  28
  29 #include <assert.h>
  30 #include <errno.h>
  31 #include <stdlib.h>
  32 #ifdef HAVE_UNISTD_H
  33 # include <unistd.h>
  34 #endif
  35 #include <string.h>
  36
  37 #include "winbase.h"
  38 #include "thread.h"
  39 #include "winternl.h"
  40
  41 /* Currently this probably works only for glibc2,
  42  * which checks for the presence of double-underscore-prepended
  43  * pthread primitives, and use them if available.
  44  * If they are not available, the libc defaults to
  45  * non-threadsafe operation (not good). */
  46
  47 #if defined(__GLIBC__) || defined(__FreeBSD__)
  48
  49 #ifndef __USE_UNIX98
  50 #define __USE_UNIX98
  51 #endif
  52
  53 #include <pthread.h>
  54 #include <signal.h>
  55
  56 #define PSTR(str) __ASM_NAME(#str)
  57
  58 /* adapt as necessary (a construct like this is used in glibc sources) */
  59 #define strong_alias(orig, alias) \
  60  asm(".globl " PSTR(alias) "\n" \
  61      "\t.set " PSTR(alias) "," PSTR(orig))
  62
  63 static int init_done;
  64
  65 static pid_t (*libc_fork)(void);
  66 static int (*libc_sigaction)(int signum, const struct sigaction *act, struct sigaction *oldact);
  67
  68 void PTHREAD_init_done(void)
  69 {
  70     init_done = 1;
  71     if (!libc_fork) libc_fork = dlsym( RTLD_NEXT, "fork" );
  72     if (!libc_sigaction) libc_sigaction = dlsym( RTLD_NEXT, "sigaction" );
  73 }
  74
  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  * also: assume that static initializer sets pointer to NULL
  83  */
  84 typedef struct {
  85   CRITICAL_SECTION *critsect;
  86 } *wine_mutex;
  87
  88 /* see wine_mutex above for comments */
  89 typedef struct {
  90   RTL_RWLOCK *lock;
  91 } *wine_rwlock;
  92
  93 typedef struct _wine_cleanup {
  94   void (*routine)(void *);
  95   void *arg;
  96 } *wine_cleanup;
  97
  98 typedef const void *key_data;
  99
 100 #define FIRST_KEY 0
 101 #define MAX_KEYS 16 /* libc6 doesn't use that many, but... */
 102
 103 #define P_OUTPUT(stuff) write(2,stuff,strlen(stuff))
 104
 105 void __pthread_initialize(void)
 106 {
 107 }
 108
 109 struct pthread_thread_init {
 110          void* (*start_routine)(void*);
 111          void* arg;
 112 };
 113
 114 static DWORD CALLBACK pthread_thread_start(LPVOID data)
 115 {
 116   struct pthread_thread_init init = *(struct pthread_thread_init*)data;
 117   HeapFree(GetProcessHeap(),0,data);
 118   return (DWORD)init.start_routine(init.arg);
 119 }
 120
 121 int pthread_create(pthread_t* thread, const pthread_attr_t* attr, void*
 122         (*start_routine)(void *), void* arg)
 123 {
 124   HANDLE hThread;
 125   struct pthread_thread_init* idata = HeapAlloc(GetProcessHeap(), 0,
 126                 sizeof(struct pthread_thread_init));
 127
 128   idata->start_routine = start_routine;
 129   idata->arg = arg;
 130   hThread = CreateThread( NULL, 0, pthread_thread_start, idata, 0,
 131                           (LPDWORD)thread);
 132
 133   if(hThread)
 134     CloseHandle(hThread);
 135   else
 136   {
 137     HeapFree(GetProcessHeap(),0,idata); /* free idata struct on failure */
 138     return EAGAIN;
 139   }
 140
 141   return 0;
 142 }
 143
 144 int pthread_cancel(pthread_t thread)
 145 {
 146   HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, FALSE, (DWORD)thread);
 147
 148   if(!TerminateThread(hThread, 0))
 149   {
 150     CloseHandle(hThread);
 151     return EINVAL;      /* return error */
 152   }
 153
 154   CloseHandle(hThread);
 155
 156   return 0;             /* return success */
 157 }
 158
 159 int pthread_join(pthread_t thread, void **value_ptr)
 160 {
 161   HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, FALSE, (DWORD)thread);
 162
 163   WaitForSingleObject(hThread, INFINITE);
 164   if(!GetExitCodeThread(hThread, (LPDWORD)value_ptr))
 165   {
 166     CloseHandle(hThread);
 167     return EINVAL; /* FIXME: make this more correctly match */
 168   }                /* windows errors */
 169
 170   CloseHandle(hThread);
 171   return 0;
 172 }
 173
 174 /*FIXME: not sure what to do with this one... */
 175 int pthread_detach(pthread_t thread)
 176 {
 177   P_OUTPUT("FIXME:pthread_detach\n");
 178   return 0;
 179 }
 180
 181 /* FIXME: we have no equivalents in win32 for the policys */
 182 /* so just keep this as a stub */
 183 int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy)
 184 {
 185   P_OUTPUT("FIXME:pthread_attr_setschedpolicy\n");
 186   return 0;
 187 }
 188
 189 /* FIXME: no win32 equivalent for scope */
 190 int pthread_attr_setscope(pthread_attr_t *attr, int scope)
 191 {
 192   P_OUTPUT("FIXME:pthread_attr_setscope\n");
 193   return 0; /* return success */
 194 }
 195
 196 /* FIXME: no win32 equivalent for schedule param */
 197 int pthread_attr_setschedparam(pthread_attr_t *attr,
 198     const struct sched_param *param)
 199 {
 200   P_OUTPUT("FIXME:pthread_attr_setschedparam\n");
 201   return 0; /* return success */
 202 }
 203
 204 int __pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
 205 {
 206   static pthread_once_t the_once = PTHREAD_ONCE_INIT;
 207   LONG once_now;
 208
 209   memcpy(&once_now,&the_once,sizeof(once_now));
 210   if (InterlockedCompareExchange((LONG*)once_control, once_now+1, once_now) == once_now)
 211     (*init_routine)();
 212   return 0;
 213 }
 214 strong_alias(__pthread_once, pthread_once);
 215
 216 void __pthread_kill_other_threads_np(void)
 217 {
 218     /* we don't need to do anything here */
 219 }
 220 strong_alias(__pthread_kill_other_threads_np, pthread_kill_other_threads_np);
 221
 222 /***** atfork *****/
 223
 224 #define MAX_ATFORK 8  /* libc doesn't need that many anyway */
 225
 226 static CRITICAL_SECTION atfork_section = CRITICAL_SECTION_INIT("atfork_section");
 227 typedef void (*atfork_handler)();
 228 static atfork_handler atfork_prepare[MAX_ATFORK];
 229 static atfork_handler atfork_parent[MAX_ATFORK];
 230 static atfork_handler atfork_child[MAX_ATFORK];
 231 static int atfork_count;
 232
 233 int __pthread_atfork(void (*prepare)(void),
 234                      void (*parent)(void),
 235                      void (*child)(void))
 236 {
 237     if (init_done) EnterCriticalSection( &atfork_section );
 238     assert( atfork_count < MAX_ATFORK );
 239     atfork_prepare[atfork_count] = prepare;
 240     atfork_parent[atfork_count] = parent;
 241     atfork_child[atfork_count] = child;
 242     atfork_count++;
 243     if (init_done) LeaveCriticalSection( &atfork_section );
 244     return 0;
 245 }
 246 strong_alias(__pthread_atfork, pthread_atfork);
 247
 248 pid_t __fork(void)
 249 {
 250     pid_t pid;
 251     int i;
 252
 253     if (!libc_fork)
 254     {
 255         libc_fork = dlsym( RTLD_NEXT, "fork" );
 256         assert( libc_fork );
 257     }
 258     EnterCriticalSection( &atfork_section );
 259     /* prepare handlers are called in reverse insertion order */
 260     for (i = atfork_count - 1; i >= 0; i--) if (atfork_prepare[i]) atfork_prepare[i]();
 261     if (!(pid = libc_fork()))
 262     {
 263         InitializeCriticalSection( &atfork_section );
 264         for (i = 0; i < atfork_count; i++) if (atfork_child[i]) atfork_child[i]();
 265     }
 266     else
 267     {
 268         for (i = 0; i < atfork_count; i++) if (atfork_parent[i]) atfork_parent[i]();
 269         LeaveCriticalSection( &atfork_section );
 270     }
 271     return pid;
 272 }
 273 strong_alias(__fork, fork);
 274
 275 /***** MUTEXES *****/
 276
 277 int __pthread_mutex_init(pthread_mutex_t *mutex,
 278                         const pthread_mutexattr_t *mutexattr)
 279 {
 280   /* glibc has a tendency to initialize mutexes very often, even
 281      in situations where they are not really used later on.
 282
 283      As for us, initializing a mutex is very expensive, we postpone
 284      the real initialization until the time the mutex is first used. */
 285
 286   ((wine_mutex)mutex)->critsect = NULL;
 287   return 0;
 288 }
 289 strong_alias(__pthread_mutex_init, pthread_mutex_init);
 290
 291 static void mutex_real_init( pthread_mutex_t *mutex )
 292 {
 293   CRITICAL_SECTION *critsect = HeapAlloc(GetProcessHeap(), 0, sizeof(CRITICAL_SECTION));
 294   InitializeCriticalSection(critsect);
 295
 296   if (InterlockedCompareExchangePointer((void**)&(((wine_mutex)mutex)->critsect),critsect,NULL) != NULL) {
 297     /* too late, some other thread already did it */
 298     DeleteCriticalSection(critsect);
 299     HeapFree(GetProcessHeap(), 0, critsect);
 300   }
 301 }
 302
 303 int __pthread_mutex_lock(pthread_mutex_t *mutex)
 304 {
 305   if (!init_done) return 0;
 306   if (!((wine_mutex)mutex)->critsect)
 307     mutex_real_init( mutex );
 308
 309   EnterCriticalSection(((wine_mutex)mutex)->critsect);
 310   return 0;
 311 }
 312 strong_alias(__pthread_mutex_lock, pthread_mutex_lock);
 313
 314 int __pthread_mutex_trylock(pthread_mutex_t *mutex)
 315 {
 316   if (!init_done) return 0;
 317   if (!((wine_mutex)mutex)->critsect)
 318     mutex_real_init( mutex );
 319
 320   if (!TryEnterCriticalSection(((wine_mutex)mutex)->critsect)) {
 321     errno = EBUSY;
 322     return -1;
 323   }
 324   return 0;
 325 }
 326 strong_alias(__pthread_mutex_trylock, pthread_mutex_trylock);
 327
 328 int __pthread_mutex_unlock(pthread_mutex_t *mutex)
 329 {
 330   if (!((wine_mutex)mutex)->critsect) return 0;
 331   LeaveCriticalSection(((wine_mutex)mutex)->critsect);
 332   return 0;
 333 }
 334 strong_alias(__pthread_mutex_unlock, pthread_mutex_unlock);
 335
 336 int __pthread_mutex_destroy(pthread_mutex_t *mutex)
 337 {
 338   if (!((wine_mutex)mutex)->critsect) return 0;
 339   if (((wine_mutex)mutex)->critsect->RecursionCount) {
 340 #if 0 /* there seems to be a bug in libc6 that makes this a bad idea */
 341     return EBUSY;
 342 #else
 343     while (((wine_mutex)mutex)->critsect->RecursionCount)
 344       LeaveCriticalSection(((wine_mutex)mutex)->critsect);
 345 #endif
 346   }
 347   DeleteCriticalSection(((wine_mutex)mutex)->critsect);
 348   HeapFree(GetProcessHeap(), 0, ((wine_mutex)mutex)->critsect);
 349   return 0;
 350 }
 351 strong_alias(__pthread_mutex_destroy, pthread_mutex_destroy);
 352
 353
 354 /***** MUTEX ATTRIBUTES *****/
 355 /* just dummies, since critical sections are always recursive */
 356
 357 int __pthread_mutexattr_init(pthread_mutexattr_t *attr)
 358 {
 359   return 0;
 360 }
 361 strong_alias(__pthread_mutexattr_init, pthread_mutexattr_init);
 362
 363 int __pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
 364 {
 365   return 0;
 366 }
 367 strong_alias(__pthread_mutexattr_destroy, pthread_mutexattr_destroy);
 368
 369 int __pthread_mutexattr_setkind_np(pthread_mutexattr_t *attr, int kind)
 370 {
 371   return 0;
 372 }
 373 strong_alias(__pthread_mutexattr_setkind_np, pthread_mutexattr_setkind_np);
 374
 375 int __pthread_mutexattr_getkind_np(pthread_mutexattr_t *attr, int *kind)
 376 {
 377   *kind = PTHREAD_MUTEX_RECURSIVE;
 378   return 0;
 379 }
 380 strong_alias(__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np);
 381
 382 int __pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind)
 383 {
 384   return 0;
 385 }
 386 strong_alias(__pthread_mutexattr_settype, pthread_mutexattr_settype);
 387
 388 int __pthread_mutexattr_gettype(pthread_mutexattr_t *attr, int *kind)
 389 {
 390   *kind = PTHREAD_MUTEX_RECURSIVE;
 391   return 0;
 392 }
 393 strong_alias(__pthread_mutexattr_gettype, pthread_mutexattr_gettype);
 394
 395
 396 /***** THREAD-SPECIFIC VARIABLES (KEYS) *****/
 397
 398 int __pthread_key_create(pthread_key_t *key, void (*destr_function)(void *))
 399 {
 400   static LONG keycnt = FIRST_KEY;
 401   *key = InterlockedExchangeAdd(&keycnt, 1);
 402   return 0;
 403 }
 404 strong_alias(__pthread_key_create, pthread_key_create);
 405
 406 int __pthread_key_delete(pthread_key_t key)
 407 {
 408   return 0;
 409 }
 410 strong_alias(__pthread_key_delete, pthread_key_delete);
 411
 412 int __pthread_setspecific(pthread_key_t key, const void *pointer)
 413 {
 414   TEB *teb = NtCurrentTeb();
 415   if (!teb->pthread_data) {
 416     teb->pthread_data = calloc(MAX_KEYS,sizeof(key_data));
 417   }
 418   ((key_data*)(teb->pthread_data))[key] = pointer;
 419   return 0;
 420 }
 421 strong_alias(__pthread_setspecific, pthread_setspecific);
 422
 423 void *__pthread_getspecific(pthread_key_t key)
 424 {
 425   TEB *teb = NtCurrentTeb();
 426   if (!teb) return NULL;
 427   if (!teb->pthread_data) return NULL;
 428   return (void *)(((key_data*)(teb->pthread_data))[key]);
 429 }
 430 strong_alias(__pthread_getspecific, pthread_getspecific);
 431
 432
 433 /***** "EXCEPTION" FRAMES *****/
 434 /* not implemented right now */
 435
 436 void _pthread_cleanup_push(struct _pthread_cleanup_buffer *buffer, void (*routine)(void *), void *arg)
 437 {
 438   ((wine_cleanup)buffer)->routine = routine;
 439   ((wine_cleanup)buffer)->arg = arg;
 440 }
 441
 442 void _pthread_cleanup_pop(struct _pthread_cleanup_buffer *buffer, int execute)
 443 {
 444   if (execute) (*(((wine_cleanup)buffer)->routine))(((wine_cleanup)buffer)->arg);
 445 }
 446
 447 void _pthread_cleanup_push_defer(struct _pthread_cleanup_buffer *buffer, void (*routine)(void *), void *arg)
 448 {
 449   _pthread_cleanup_push(buffer, routine, arg);
 450 }
 451
 452 void _pthread_cleanup_pop_restore(struct _pthread_cleanup_buffer *buffer, int execute)
 453 {
 454   _pthread_cleanup_pop(buffer, execute);
 455 }
 456
 457
 458 /***** CONDITIONS *****/
 459 /* not implemented right now */
 460
 461 int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *cond_attr)
 462 {
 463   P_OUTPUT("FIXME:pthread_cond_init\n");
 464   return 0;
 465 }
 466
 467 int pthread_cond_destroy(pthread_cond_t *cond)
 468 {
 469   P_OUTPUT("FIXME:pthread_cond_destroy\n");
 470   return 0;
 471 }
 472
 473 int pthread_cond_signal(pthread_cond_t *cond)
 474 {
 475   P_OUTPUT("FIXME:pthread_cond_signal\n");
 476   return 0;
 477 }
 478
 479 int pthread_cond_broadcast(pthread_cond_t *cond)
 480 {
 481   P_OUTPUT("FIXME:pthread_cond_broadcast\n");
 482   return 0;
 483 }
 484
 485 int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
 486 {
 487   P_OUTPUT("FIXME:pthread_cond_wait\n");
 488   return 0;
 489 }
 490
 491 int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, const struct timespec *abstime)
 492 {
 493   P_OUTPUT("FIXME:pthread_cond_timedwait\n");
 494   return 0;
 495 }
 496
 497 /**** CONDITION ATTRIBUTES *****/
 498 /* not implemented right now */
 499
 500 int pthread_condattr_init(pthread_condattr_t *attr)
 501 {
 502   return 0;
 503 }
 504
 505 int pthread_condattr_destroy(pthread_condattr_t *attr)
 506 {
 507   return 0;
 508 }
 509
 510 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 2)
 511 /***** READ-WRITE LOCKS *****/
 512
 513 static void rwlock_real_init(pthread_rwlock_t *rwlock)
 514 {
 515   RTL_RWLOCK *lock = HeapAlloc(GetProcessHeap(), 0, sizeof(RTL_RWLOCK));
 516   RtlInitializeResource(lock);
 517
 518   if (InterlockedCompareExchangePointer((void**)&(((wine_rwlock)rwlock)->lock),lock,NULL) != NULL) {
 519     /* too late, some other thread already did it */
 520     RtlDeleteResource(lock);
 521     HeapFree(GetProcessHeap(), 0, lock);
 522   }
 523 }
 524
 525 int __pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *rwlock_attr)
 526 {
 527   ((wine_rwlock)rwlock)->lock = NULL;
 528   return 0;
 529 }
 530 strong_alias(__pthread_rwlock_init, pthread_rwlock_init);
 531
 532 int __pthread_rwlock_destroy(pthread_rwlock_t *rwlock)
 533 {
 534   if (!((wine_rwlock)rwlock)->lock) return 0;
 535   RtlDeleteResource(((wine_rwlock)rwlock)->lock);
 536   HeapFree(GetProcessHeap(), 0, ((wine_rwlock)rwlock)->lock);
 537   return 0;
 538 }
 539 strong_alias(__pthread_rwlock_destroy, pthread_rwlock_destroy);
 540
 541 int __pthread_rwlock_rdlock(pthread_rwlock_t *rwlock)
 542 {
 543   if (!init_done) return 0;
 544   if (!((wine_rwlock)rwlock)->lock)
 545     rwlock_real_init( rwlock );
 546
 547   while(TRUE)
 548     if (RtlAcquireResourceShared(((wine_rwlock)rwlock)->lock, TRUE))
 549       return 0;
 550 }
 551 strong_alias(__pthread_rwlock_rdlock, pthread_rwlock_rdlock);
 552
 553 int __pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock)
 554 {
 555   if (!init_done) return 0;
 556   if (!((wine_rwlock)rwlock)->lock)
 557     rwlock_real_init( rwlock );
 558
 559   if (!RtlAcquireResourceShared(((wine_rwlock)rwlock)->lock, FALSE)) {
 560     errno = EBUSY;
 561     return -1;
 562   }
 563   return 0;
 564 }
 565 strong_alias(__pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock);
 566
 567 int __pthread_rwlock_wrlock(pthread_rwlock_t *rwlock)
 568 {
 569   if (!init_done) return 0;
 570   if (!((wine_rwlock)rwlock)->lock)
 571     rwlock_real_init( rwlock );
 572
 573   while(TRUE)
 574     if (RtlAcquireResourceExclusive(((wine_rwlock)rwlock)->lock, TRUE))
 575       return 0;
 576 }
 577 strong_alias(__pthread_rwlock_wrlock, pthread_rwlock_wrlock);
 578
 579 int __pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)
 580 {
 581   if (!init_done) return 0;
 582   if (!((wine_rwlock)rwlock)->lock)
 583     rwlock_real_init( rwlock );
 584
 585   if (!RtlAcquireResourceExclusive(((wine_rwlock)rwlock)->lock, FALSE)) {
 586     errno = EBUSY;
 587     return -1;
 588   }
 589   return 0;
 590 }
 591 strong_alias(__pthread_rwlock_trywrlock, pthread_rwlock_trywrlock);
 592
 593 int __pthread_rwlock_unlock(pthread_rwlock_t *rwlock)
 594 {
 595   if (!((wine_rwlock)rwlock)->lock) return 0;
 596   RtlReleaseResource( ((wine_rwlock)rwlock)->lock );
 597   return 0;
 598 }
 599 strong_alias(__pthread_rwlock_unlock, pthread_rwlock_unlock);
 600
 601 /**** READ-WRITE LOCK ATTRIBUTES *****/
 602 /* not implemented right now */
 603
 604 int pthread_rwlockattr_init(pthread_rwlockattr_t *attr)
 605 {
 606   return 0;
 607 }
 608
 609 int __pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr)
 610 {
 611   return 0;
 612 }
 613 strong_alias(__pthread_rwlockattr_destroy, pthread_rwlockattr_destroy);
 614
 615 int pthread_rwlockattr_getkind_np(const pthread_rwlockattr_t *attr, int *pref)
 616 {
 617   *pref = 0;
 618   return 0;
 619 }
 620
 621 int pthread_rwlockattr_setkind_np(pthread_rwlockattr_t *attr, int pref)
 622 {
 623   return 0;
 624 }
 625 #endif /* glibc 2.2 */
 626
 627 /***** MISC *****/
 628
 629 pthread_t pthread_self(void)
 630 {
 631   return (pthread_t)GetCurrentThreadId();
 632 }
 633
 634 int pthread_equal(pthread_t thread1, pthread_t thread2)
 635 {
 636   return (DWORD)thread1 == (DWORD)thread2;
 637 }
 638
 639 void pthread_exit(void *retval)
 640 {
 641   /* FIXME: pthread cleanup */
 642   ExitThread((DWORD)retval);
 643 }
 644
 645 int pthread_setcanceltype(int type, int *oldtype)
 646 {
 647   if (oldtype) *oldtype = PTHREAD_CANCEL_ASYNCHRONOUS;
 648   return 0;
 649 }
 650
 651 /***** ANTI-OVERRIDES *****/
 652 /* pthreads tries to override these, point them back to libc */
 653
 654 int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
 655 {
 656     if (!libc_sigaction)
 657     {
 658         libc_sigaction = dlsym( RTLD_NEXT, "sigaction" );
 659         assert( libc_sigaction );
 660     }
 661     return libc_sigaction(signum, act, oldact);
 662 }
 663
 664 #else /* __GLIBC__ || __FREEBSD__ */
 665
 666 void PTHREAD_init_done(void)
 667 {
 668 }
 669
 670 #endif /* __GLIBC__ || __FREEBSD__ */