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