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 struct _pthread_cleanup_buffer;
  25
  26 #include "config.h"
  27 #include "wine/port.h"
  28
  29 #define _GNU_SOURCE /* we may need to override some GNU extensions */
  30
  31 #include <assert.h>
  32 #include <errno.h>
  33 #include <stdlib.h>
  34 #ifdef HAVE_UNISTD_H
  35 # include <unistd.h>
  36 #endif
  37 #include <string.h>
  38
  39 #include "winbase.h"
  40 #include "thread.h"
  41 #include "winternl.h"
  42
  43 /* Currently this probably works only for glibc2,
  44  * which checks for the presence of double-underscore-prepended
  45  * pthread primitives, and use them if available.
  46  * If they are not available, the libc defaults to
  47  * non-threadsafe operation (not good). */
  48
  49 #if defined(__GLIBC__) || defined(__FreeBSD__)
  50
  51 #ifndef __USE_UNIX98
  52 #define __USE_UNIX98
  53 #endif
  54
  55 #include <pthread.h>
  56 #include <signal.h>
  57
  58 #define PSTR(str) __ASM_NAME(#str)
  59
  60 /* adapt as necessary (a construct like this is used in glibc sources) */
  61 #define strong_alias(orig, alias) \
  62  asm(".globl " PSTR(alias) "\n" \
  63      "\t.set " PSTR(alias) "," PSTR(orig))
  64
  65 static int init_done;
  66
  67 static pid_t (*libc_fork)(void);
  68 static int (*libc_sigaction)(int signum, const struct sigaction *act, struct sigaction *oldact);
  69
  70 void PTHREAD_init_done(void)
  71 {
  72     init_done = 1;
  73     if (!libc_fork) libc_fork = dlsym( RTLD_NEXT, "fork" );
  74     if (!libc_sigaction) libc_sigaction = dlsym( RTLD_NEXT, "sigaction" );
  75 }
  76
  77
  78 /* NOTE: This is a truly extremely incredibly ugly hack!
  79  * But it does seem to work... */
  80
  81 /* assume that pthread_mutex_t has room for at least one pointer,
  82  * and hope that the users of pthread_mutex_t considers it opaque
  83  * (never checks what's in it)
  84  * also: assume that static initializer sets pointer to NULL
  85  */
  86 typedef struct {
  87   CRITICAL_SECTION *critsect;
  88 } *wine_mutex;
  89
  90 /* see wine_mutex above for comments */
  91 typedef struct {
  92   RTL_RWLOCK *lock;
  93 } *wine_rwlock;
  94
  95 typedef struct _wine_cleanup {
  96   void (*routine)(void *);
  97   void *arg;
  98 } *wine_cleanup;
  99
 100 typedef const void *key_data;
 101
 102 #define FIRST_KEY 0
 103 #define MAX_KEYS 16 /* libc6 doesn't use that many, but... */
 104
 105 #define P_OUTPUT(stuff) write(2,stuff,strlen(stuff))
 106
 107 void __pthread_initialize(void)
 108 {
 109 }
 110
 111 struct pthread_thread_init {
 112          void* (*start_routine)(void*);
 113          void* arg;
 114 };
 115
 116 static DWORD CALLBACK pthread_thread_start(LPVOID data)
 117 {
 118   struct pthread_thread_init init = *(struct pthread_thread_init*)data;
 119   HeapFree(GetProcessHeap(),0,data);
 120   return (DWORD)init.start_routine(init.arg);
 121 }
 122
 123 int pthread_create(pthread_t* thread, const pthread_attr_t* attr, void*
 124         (*start_routine)(void *), void* arg)
 125 {
 126   HANDLE hThread;
 127   struct pthread_thread_init* idata = HeapAlloc(GetProcessHeap(), 0,
 128                 sizeof(struct pthread_thread_init));
 129
 130   idata->start_routine = start_routine;
 131   idata->arg = arg;
 132   hThread = CreateThread( NULL, 0, pthread_thread_start, idata, 0,
 133                           (LPDWORD)thread);
 134
 135   if(hThread)
 136     CloseHandle(hThread);
 137   else
 138   {
 139     HeapFree(GetProcessHeap(),0,idata); /* free idata struct on failure */
 140     return EAGAIN;
 141   }
 142
 143   return 0;
 144 }
 145
 146 int pthread_cancel(pthread_t thread)
 147 {
 148   HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, FALSE, (DWORD)thread);
 149
 150   if(!TerminateThread(hThread, 0))
 151   {
 152     CloseHandle(hThread);
 153     return EINVAL;      /* return error */
 154   }
 155
 156   CloseHandle(hThread);
 157
 158   return 0;             /* return success */
 159 }
 160
 161 int pthread_join(pthread_t thread, void **value_ptr)
 162 {
 163   HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, FALSE, (DWORD)thread);
 164
 165   WaitForSingleObject(hThread, INFINITE);
 166   if(!GetExitCodeThread(hThread, (LPDWORD)value_ptr))
 167   {
 168     CloseHandle(hThread);
 169     return EINVAL; /* FIXME: make this more correctly match */
 170   }                /* windows errors */
 171
 172   CloseHandle(hThread);
 173   return 0;
 174 }
 175
 176 /*FIXME: not sure what to do with this one... */
 177 int pthread_detach(pthread_t thread)
 178 {
 179   P_OUTPUT("FIXME:pthread_detach\n");
 180   return 0;
 181 }
 182
 183 /* FIXME: we have no equivalents in win32 for the policys */
 184 /* so just keep this as a stub */
 185 int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy)
 186 {
 187   P_OUTPUT("FIXME:pthread_attr_setschedpolicy\n");
 188   return 0;
 189 }
 190
 191 /* FIXME: no win32 equivalent for scope */
 192 int pthread_attr_setscope(pthread_attr_t *attr, int scope)
 193 {
 194   P_OUTPUT("FIXME:pthread_attr_setscope\n");
 195   return 0; /* return success */
 196 }
 197
 198 /* FIXME: no win32 equivalent for schedule param */
 199 int pthread_attr_setschedparam(pthread_attr_t *attr,
 200     const struct sched_param *param)
 201 {
 202   P_OUTPUT("FIXME:pthread_attr_setschedparam\n");
 203   return 0; /* return success */
 204 }
 205
 206 int __pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
 207 {
 208   static pthread_once_t the_once = PTHREAD_ONCE_INIT;
 209   LONG once_now;
 210
 211   memcpy(&once_now,&the_once,sizeof(once_now));
 212   if (InterlockedCompareExchange((LONG*)once_control, once_now+1, once_now) == once_now)
 213     (*init_routine)();
 214   return 0;
 215 }
 216 strong_alias(__pthread_once, pthread_once);
 217
 218 void __pthread_kill_other_threads_np(void)
 219 {
 220     /* we don't need to do anything here */
 221 }
 222 strong_alias(__pthread_kill_other_threads_np, pthread_kill_other_threads_np);
 223
 224 /***** atfork *****/
 225
 226 #define MAX_ATFORK 8  /* libc doesn't need that many anyway */
 227
 228 static CRITICAL_SECTION atfork_section = CRITICAL_SECTION_INIT("atfork_section");
 229 typedef void (*atfork_handler)();
 230 static atfork_handler atfork_prepare[MAX_ATFORK];
 231 static atfork_handler atfork_parent[MAX_ATFORK];
 232 static atfork_handler atfork_child[MAX_ATFORK];
 233 static int atfork_count;
 234
 235 int __pthread_atfork(void (*prepare)(void),
 236                      void (*parent)(void),
 237                      void (*child)(void))
 238 {
 239     if (init_done) EnterCriticalSection( &atfork_section );
 240     assert( atfork_count < MAX_ATFORK );
 241     atfork_prepare[atfork_count] = prepare;
 242     atfork_parent[atfork_count] = parent;
 243     atfork_child[atfork_count] = child;
 244     atfork_count++;
 245     if (init_done) LeaveCriticalSection( &atfork_section );
 246     return 0;
 247 }
 248 strong_alias(__pthread_atfork, pthread_atfork);
 249
 250 pid_t __fork(void)
 251 {
 252     pid_t pid;
 253     int i;
 254
 255     if (!libc_fork)
 256     {
 257         libc_fork = dlsym( RTLD_NEXT, "fork" );
 258         assert( libc_fork );
 259     }
 260     EnterCriticalSection( &atfork_section );
 261     /* prepare handlers are called in reverse insertion order */
 262     for (i = atfork_count - 1; i >= 0; i--) if (atfork_prepare[i]) atfork_prepare[i]();
 263     if (!(pid = libc_fork()))
 264     {
 265         InitializeCriticalSection( &atfork_section );
 266         for (i = 0; i < atfork_count; i++) if (atfork_child[i]) atfork_child[i]();
 267     }
 268     else
 269     {
 270         for (i = 0; i < atfork_count; i++) if (atfork_parent[i]) atfork_parent[i]();
 271         LeaveCriticalSection( &atfork_section );
 272     }
 273     return pid;
 274 }
 275 strong_alias(__fork, fork);
 276
 277 /***** MUTEXES *****/
 278
 279 int __pthread_mutex_init(pthread_mutex_t *mutex,
 280                         const pthread_mutexattr_t *mutexattr)
 281 {
 282   /* glibc has a tendency to initialize mutexes very often, even
 283      in situations where they are not really used later on.
 284
 285      As for us, initializing a mutex is very expensive, we postpone
 286      the real initialization until the time the mutex is first used. */
 287
 288   ((wine_mutex)mutex)->critsect = NULL;
 289   return 0;
 290 }
 291 strong_alias(__pthread_mutex_init, pthread_mutex_init);
 292
 293 static void mutex_real_init( pthread_mutex_t *mutex )
 294 {
 295   CRITICAL_SECTION *critsect = HeapAlloc(GetProcessHeap(), 0, sizeof(CRITICAL_SECTION));
 296   InitializeCriticalSection(critsect);
 297
 298   if (InterlockedCompareExchangePointer((void**)&(((wine_mutex)mutex)->critsect),critsect,NULL) != NULL) {
 299     /* too late, some other thread already did it */
 300     DeleteCriticalSection(critsect);
 301     HeapFree(GetProcessHeap(), 0, critsect);
 302   }
 303 }
 304
 305 int __pthread_mutex_lock(pthread_mutex_t *mutex)
 306 {
 307   if (!init_done) return 0;
 308   if (!((wine_mutex)mutex)->critsect)
 309     mutex_real_init( mutex );
 310
 311   EnterCriticalSection(((wine_mutex)mutex)->critsect);
 312   return 0;
 313 }
 314 strong_alias(__pthread_mutex_lock, pthread_mutex_lock);
 315
 316 int __pthread_mutex_trylock(pthread_mutex_t *mutex)
 317 {
 318   if (!init_done) return 0;
 319   if (!((wine_mutex)mutex)->critsect)
 320     mutex_real_init( mutex );
 321
 322   if (!TryEnterCriticalSection(((wine_mutex)mutex)->critsect)) {
 323     errno = EBUSY;
 324     return -1;
 325   }
 326   return 0;
 327 }
 328 strong_alias(__pthread_mutex_trylock, pthread_mutex_trylock);
 329
 330 int __pthread_mutex_unlock(pthread_mutex_t *mutex)
 331 {
 332   if (!((wine_mutex)mutex)->critsect) return 0;
 333   LeaveCriticalSection(((wine_mutex)mutex)->critsect);
 334   return 0;
 335 }
 336 strong_alias(__pthread_mutex_unlock, pthread_mutex_unlock);
 337
 338 int __pthread_mutex_destroy(pthread_mutex_t *mutex)
 339 {
 340   if (!((wine_mutex)mutex)->critsect) return 0;
 341   if (((wine_mutex)mutex)->critsect->RecursionCount) {
 342 #if 0 /* there seems to be a bug in libc6 that makes this a bad idea */
 343     return EBUSY;
 344 #else
 345     while (((wine_mutex)mutex)->critsect->RecursionCount)
 346       LeaveCriticalSection(((wine_mutex)mutex)->critsect);
 347 #endif
 348   }
 349   DeleteCriticalSection(((wine_mutex)mutex)->critsect);
 350   HeapFree(GetProcessHeap(), 0, ((wine_mutex)mutex)->critsect);
 351   return 0;
 352 }
 353 strong_alias(__pthread_mutex_destroy, pthread_mutex_destroy);
 354
 355
 356 /***** MUTEX ATTRIBUTES *****/
 357 /* just dummies, since critical sections are always recursive */
 358
 359 int __pthread_mutexattr_init(pthread_mutexattr_t *attr)
 360 {
 361   return 0;
 362 }
 363 strong_alias(__pthread_mutexattr_init, pthread_mutexattr_init);
 364
 365 int __pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
 366 {
 367   return 0;
 368 }
 369 strong_alias(__pthread_mutexattr_destroy, pthread_mutexattr_destroy);
 370
 371 int __pthread_mutexattr_setkind_np(pthread_mutexattr_t *attr, int kind)
 372 {
 373   return 0;
 374 }
 375 strong_alias(__pthread_mutexattr_setkind_np, pthread_mutexattr_setkind_np);
 376
 377 int __pthread_mutexattr_getkind_np(pthread_mutexattr_t *attr, int *kind)
 378 {
 379   *kind = PTHREAD_MUTEX_RECURSIVE;
 380   return 0;
 381 }
 382 strong_alias(__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np);
 383
 384 int __pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind)
 385 {
 386   return 0;
 387 }
 388 strong_alias(__pthread_mutexattr_settype, pthread_mutexattr_settype);
 389
 390 int __pthread_mutexattr_gettype(pthread_mutexattr_t *attr, int *kind)
 391 {
 392   *kind = PTHREAD_MUTEX_RECURSIVE;
 393   return 0;
 394 }
 395 strong_alias(__pthread_mutexattr_gettype, pthread_mutexattr_gettype);
 396
 397
 398 /***** THREAD-SPECIFIC VARIABLES (KEYS) *****/
 399
 400 int __pthread_key_create(pthread_key_t *key, void (*destr_function)(void *))
 401 {
 402   static LONG keycnt = FIRST_KEY;
 403   *key = InterlockedExchangeAdd(&keycnt, 1);
 404   return 0;
 405 }
 406 strong_alias(__pthread_key_create, pthread_key_create);
 407
 408 int __pthread_key_delete(pthread_key_t key)
 409 {
 410   return 0;
 411 }
 412 strong_alias(__pthread_key_delete, pthread_key_delete);
 413
 414 int __pthread_setspecific(pthread_key_t key, const void *pointer)
 415 {
 416   TEB *teb = NtCurrentTeb();
 417   if (!teb->pthread_data) {
 418     teb->pthread_data = calloc(MAX_KEYS,sizeof(key_data));
 419   }
 420   ((key_data*)(teb->pthread_data))[key] = pointer;
 421   return 0;
 422 }
 423 strong_alias(__pthread_setspecific, pthread_setspecific);
 424
 425 void *__pthread_getspecific(pthread_key_t key)
 426 {
 427   TEB *teb = NtCurrentTeb();
 428   if (!teb) return NULL;
 429   if (!teb->pthread_data) return NULL;
 430   return (void *)(((key_data*)(teb->pthread_data))[key]);
 431 }
 432 strong_alias(__pthread_getspecific, pthread_getspecific);
 433
 434
 435 /***** "EXCEPTION" FRAMES *****/
 436 /* not implemented right now */
 437
 438 void _pthread_cleanup_push(struct _pthread_cleanup_buffer *buffer, void (*routine)(void *), void *arg)
 439 {
 440   ((wine_cleanup)buffer)->routine = routine;
 441   ((wine_cleanup)buffer)->arg = arg;
 442 }
 443
 444 void _pthread_cleanup_pop(struct _pthread_cleanup_buffer *buffer, int execute)
 445 {
 446   if (execute) (*(((wine_cleanup)buffer)->routine))(((wine_cleanup)buffer)->arg);
 447 }
 448
 449 void _pthread_cleanup_push_defer(struct _pthread_cleanup_buffer *buffer, void (*routine)(void *), void *arg)
 450 {
 451   _pthread_cleanup_push(buffer, routine, arg);
 452 }
 453
 454 void _pthread_cleanup_pop_restore(struct _pthread_cleanup_buffer *buffer, int execute)
 455 {
 456   _pthread_cleanup_pop(buffer, execute);
 457 }
 458
 459
 460 /***** CONDITIONS *****/
 461 /* not implemented right now */
 462
 463 int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *cond_attr)
 464 {
 465   P_OUTPUT("FIXME:pthread_cond_init\n");
 466   return 0;
 467 }
 468
 469 int pthread_cond_destroy(pthread_cond_t *cond)
 470 {
 471   P_OUTPUT("FIXME:pthread_cond_destroy\n");
 472   return 0;
 473 }
 474
 475 int pthread_cond_signal(pthread_cond_t *cond)
 476 {
 477   P_OUTPUT("FIXME:pthread_cond_signal\n");
 478   return 0;
 479 }
 480
 481 int pthread_cond_broadcast(pthread_cond_t *cond)
 482 {
 483   P_OUTPUT("FIXME:pthread_cond_broadcast\n");
 484   return 0;
 485 }
 486
 487 int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
 488 {
 489   P_OUTPUT("FIXME:pthread_cond_wait\n");
 490   return 0;
 491 }
 492
 493 int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, const struct timespec *abstime)
 494 {
 495   P_OUTPUT("FIXME:pthread_cond_timedwait\n");
 496   return 0;
 497 }
 498
 499 /**** CONDITION ATTRIBUTES *****/
 500 /* not implemented right now */
 501
 502 int pthread_condattr_init(pthread_condattr_t *attr)
 503 {
 504   return 0;
 505 }
 506
 507 int pthread_condattr_destroy(pthread_condattr_t *attr)
 508 {
 509   return 0;
 510 }
 511
 512 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 2)
 513 /***** READ-WRITE LOCKS *****/
 514
 515 static void rwlock_real_init(pthread_rwlock_t *rwlock)
 516 {
 517   RTL_RWLOCK *lock = HeapAlloc(GetProcessHeap(), 0, sizeof(RTL_RWLOCK));
 518   RtlInitializeResource(lock);
 519
 520   if (InterlockedCompareExchangePointer((void**)&(((wine_rwlock)rwlock)->lock),lock,NULL) != NULL) {
 521     /* too late, some other thread already did it */
 522     RtlDeleteResource(lock);
 523     HeapFree(GetProcessHeap(), 0, lock);
 524   }
 525 }
 526
 527 int __pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *rwlock_attr)
 528 {
 529   ((wine_rwlock)rwlock)->lock = NULL;
 530   return 0;
 531 }
 532 strong_alias(__pthread_rwlock_init, pthread_rwlock_init);
 533
 534 int __pthread_rwlock_destroy(pthread_rwlock_t *rwlock)
 535 {
 536   if (!((wine_rwlock)rwlock)->lock) return 0;
 537   RtlDeleteResource(((wine_rwlock)rwlock)->lock);
 538   HeapFree(GetProcessHeap(), 0, ((wine_rwlock)rwlock)->lock);
 539   return 0;
 540 }
 541 strong_alias(__pthread_rwlock_destroy, pthread_rwlock_destroy);
 542
 543 int __pthread_rwlock_rdlock(pthread_rwlock_t *rwlock)
 544 {
 545   if (!init_done) return 0;
 546   if (!((wine_rwlock)rwlock)->lock)
 547     rwlock_real_init( rwlock );
 548
 549   while(TRUE)
 550     if (RtlAcquireResourceShared(((wine_rwlock)rwlock)->lock, TRUE))
 551       return 0;
 552 }
 553 strong_alias(__pthread_rwlock_rdlock, pthread_rwlock_rdlock);
 554
 555 int __pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock)
 556 {
 557   if (!init_done) return 0;
 558   if (!((wine_rwlock)rwlock)->lock)
 559     rwlock_real_init( rwlock );
 560
 561   if (!RtlAcquireResourceShared(((wine_rwlock)rwlock)->lock, FALSE)) {
 562     errno = EBUSY;
 563     return -1;
 564   }
 565   return 0;
 566 }
 567 strong_alias(__pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock);
 568
 569 int __pthread_rwlock_wrlock(pthread_rwlock_t *rwlock)
 570 {
 571   if (!init_done) return 0;
 572   if (!((wine_rwlock)rwlock)->lock)
 573     rwlock_real_init( rwlock );
 574
 575   while(TRUE)
 576     if (RtlAcquireResourceExclusive(((wine_rwlock)rwlock)->lock, TRUE))
 577       return 0;
 578 }
 579 strong_alias(__pthread_rwlock_wrlock, pthread_rwlock_wrlock);
 580
 581 int __pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)
 582 {
 583   if (!init_done) return 0;
 584   if (!((wine_rwlock)rwlock)->lock)
 585     rwlock_real_init( rwlock );
 586
 587   if (!RtlAcquireResourceExclusive(((wine_rwlock)rwlock)->lock, FALSE)) {
 588     errno = EBUSY;
 589     return -1;
 590   }
 591   return 0;
 592 }
 593 strong_alias(__pthread_rwlock_trywrlock, pthread_rwlock_trywrlock);
 594
 595 int __pthread_rwlock_unlock(pthread_rwlock_t *rwlock)
 596 {
 597   if (!((wine_rwlock)rwlock)->lock) return 0;
 598   RtlReleaseResource( ((wine_rwlock)rwlock)->lock );
 599   return 0;
 600 }
 601 strong_alias(__pthread_rwlock_unlock, pthread_rwlock_unlock);
 602
 603 /**** READ-WRITE LOCK ATTRIBUTES *****/
 604 /* not implemented right now */
 605
 606 int pthread_rwlockattr_init(pthread_rwlockattr_t *attr)
 607 {
 608   return 0;
 609 }
 610
 611 int __pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr)
 612 {
 613   return 0;
 614 }
 615 strong_alias(__pthread_rwlockattr_destroy, pthread_rwlockattr_destroy);
 616
 617 int pthread_rwlockattr_getkind_np(const pthread_rwlockattr_t *attr, int *pref)
 618 {
 619   *pref = 0;
 620   return 0;
 621 }
 622
 623 int pthread_rwlockattr_setkind_np(pthread_rwlockattr_t *attr, int pref)
 624 {
 625   return 0;
 626 }
 627 #endif /* glibc 2.2 */
 628
 629 /***** MISC *****/
 630
 631 pthread_t pthread_self(void)
 632 {
 633   return (pthread_t)GetCurrentThreadId();
 634 }
 635
 636 int pthread_equal(pthread_t thread1, pthread_t thread2)
 637 {
 638   return (DWORD)thread1 == (DWORD)thread2;
 639 }
 640
 641 void pthread_exit(void *retval)
 642 {
 643   /* FIXME: pthread cleanup */
 644   ExitThread((DWORD)retval);
 645 }
 646
 647 int pthread_setcanceltype(int type, int *oldtype)
 648 {
 649   if (oldtype) *oldtype = PTHREAD_CANCEL_ASYNCHRONOUS;
 650   return 0;
 651 }
 652
 653 /***** ANTI-OVERRIDES *****/
 654 /* pthreads tries to override these, point them back to libc */
 655
 656 int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
 657 {
 658     if (!libc_sigaction)
 659     {
 660         libc_sigaction = dlsym( RTLD_NEXT, "sigaction" );
 661         assert( libc_sigaction );
 662     }
 663     return libc_sigaction(signum, act, oldact);
 664 }
 665
 666 #else /* __GLIBC__ || __FREEBSD__ */
 667
 668 void PTHREAD_init_done(void)
 669 {
 670 }
 671
 672 #endif /* __GLIBC__ || __FREEBSD__ */