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;
 202
 203   memcpy(&once_now,&the_once,sizeof(once_now));
 204   if (InterlockedCompareExchange((LONG*)once_control, once_now+1, once_now) == once_now)
 205     (*init_routine)();
 206   return 0;
 207 }
 208 strong_alias(__pthread_once, pthread_once);
 209
 210 void __pthread_kill_other_threads_np(void)
 211 {
 212     /* we don't need to do anything here */
 213 }
 214 strong_alias(__pthread_kill_other_threads_np, pthread_kill_other_threads_np);
 215
 216 /***** atfork *****/
 217
 218 #define MAX_ATFORK 8  /* libc doesn't need that many anyway */
 219
 220 static CRITICAL_SECTION atfork_section = CRITICAL_SECTION_INIT("atfork_section");
 221 typedef void (*atfork_handler)();
 222 static atfork_handler atfork_prepare[MAX_ATFORK];
 223 static atfork_handler atfork_parent[MAX_ATFORK];
 224 static atfork_handler atfork_child[MAX_ATFORK];
 225 static int atfork_count;
 226
 227 int __pthread_atfork(void (*prepare)(void),
 228                      void (*parent)(void),
 229                      void (*child)(void))
 230 {
 231     if (init_done) EnterCriticalSection( &atfork_section );
 232     assert( atfork_count < MAX_ATFORK );
 233     atfork_prepare[atfork_count] = prepare;
 234     atfork_parent[atfork_count] = parent;
 235     atfork_child[atfork_count] = child;
 236     atfork_count++;
 237     if (init_done) LeaveCriticalSection( &atfork_section );
 238     return 0;
 239 }
 240 strong_alias(__pthread_atfork, pthread_atfork);
 241
 242 pid_t __fork(void)
 243 {
 244     pid_t pid;
 245     int i;
 246
 247     if (!libc_fork)
 248     {
 249         libc_fork = dlsym( RTLD_NEXT, "fork" );
 250         assert( libc_fork );
 251     }
 252     EnterCriticalSection( &atfork_section );
 253     /* prepare handlers are called in reverse insertion order */
 254     for (i = atfork_count - 1; i >= 0; i--) if (atfork_prepare[i]) atfork_prepare[i]();
 255     if (!(pid = libc_fork()))
 256     {
 257         InitializeCriticalSection( &atfork_section );
 258         for (i = 0; i < atfork_count; i++) if (atfork_child[i]) atfork_child[i]();
 259     }
 260     else
 261     {
 262         for (i = 0; i < atfork_count; i++) if (atfork_parent[i]) atfork_parent[i]();
 263         LeaveCriticalSection( &atfork_section );
 264     }
 265     return pid;
 266 }
 267 strong_alias(__fork, fork);
 268
 269 /***** MUTEXES *****/
 270
 271 int __pthread_mutex_init(pthread_mutex_t *mutex,
 272                         const pthread_mutexattr_t *mutexattr)
 273 {
 274   /* glibc has a tendency to initialize mutexes very often, even
 275      in situations where they are not really used later on.
 276
 277      As for us, initializing a mutex is very expensive, we postpone
 278      the real initialization until the time the mutex is first used. */
 279
 280   ((wine_mutex)mutex)->critsect = NULL;
 281   return 0;
 282 }
 283 strong_alias(__pthread_mutex_init, pthread_mutex_init);
 284
 285 static void mutex_real_init( pthread_mutex_t *mutex )
 286 {
 287   CRITICAL_SECTION *critsect = HeapAlloc(GetProcessHeap(), 0, sizeof(CRITICAL_SECTION));
 288   InitializeCriticalSection(critsect);
 289
 290   if (InterlockedCompareExchangePointer((void**)&(((wine_mutex)mutex)->critsect),critsect,NULL) != NULL) {
 291     /* too late, some other thread already did it */
 292     DeleteCriticalSection(critsect);
 293     HeapFree(GetProcessHeap(), 0, critsect);
 294   }
 295 }
 296
 297 int __pthread_mutex_lock(pthread_mutex_t *mutex)
 298 {
 299   if (!init_done) return 0;
 300   if (!((wine_mutex)mutex)->critsect)
 301     mutex_real_init( mutex );
 302
 303   EnterCriticalSection(((wine_mutex)mutex)->critsect);
 304   return 0;
 305 }
 306 strong_alias(__pthread_mutex_lock, pthread_mutex_lock);
 307
 308 int __pthread_mutex_trylock(pthread_mutex_t *mutex)
 309 {
 310   if (!init_done) return 0;
 311   if (!((wine_mutex)mutex)->critsect)
 312     mutex_real_init( mutex );
 313
 314   if (!TryEnterCriticalSection(((wine_mutex)mutex)->critsect)) {
 315     errno = EBUSY;
 316     return -1;
 317   }
 318   return 0;
 319 }
 320 strong_alias(__pthread_mutex_trylock, pthread_mutex_trylock);
 321
 322 int __pthread_mutex_unlock(pthread_mutex_t *mutex)
 323 {
 324   if (!((wine_mutex)mutex)->critsect) return 0;
 325   LeaveCriticalSection(((wine_mutex)mutex)->critsect);
 326   return 0;
 327 }
 328 strong_alias(__pthread_mutex_unlock, pthread_mutex_unlock);
 329
 330 int __pthread_mutex_destroy(pthread_mutex_t *mutex)
 331 {
 332   if (!((wine_mutex)mutex)->critsect) return 0;
 333   if (((wine_mutex)mutex)->critsect->RecursionCount) {
 334 #if 0 /* there seems to be a bug in libc6 that makes this a bad idea */
 335     return EBUSY;
 336 #else
 337     while (((wine_mutex)mutex)->critsect->RecursionCount)
 338       LeaveCriticalSection(((wine_mutex)mutex)->critsect);
 339 #endif
 340   }
 341   DeleteCriticalSection(((wine_mutex)mutex)->critsect);
 342   HeapFree(GetProcessHeap(), 0, ((wine_mutex)mutex)->critsect);
 343   return 0;
 344 }
 345 strong_alias(__pthread_mutex_destroy, pthread_mutex_destroy);
 346
 347
 348 /***** MUTEX ATTRIBUTES *****/
 349 /* just dummies, since critical sections are always recursive */
 350
 351 int __pthread_mutexattr_init(pthread_mutexattr_t *attr)
 352 {
 353   return 0;
 354 }
 355 strong_alias(__pthread_mutexattr_init, pthread_mutexattr_init);
 356
 357 int __pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
 358 {
 359   return 0;
 360 }
 361 strong_alias(__pthread_mutexattr_destroy, pthread_mutexattr_destroy);
 362
 363 int __pthread_mutexattr_setkind_np(pthread_mutexattr_t *attr, int kind)
 364 {
 365   return 0;
 366 }
 367 strong_alias(__pthread_mutexattr_setkind_np, pthread_mutexattr_setkind_np);
 368
 369 int __pthread_mutexattr_getkind_np(pthread_mutexattr_t *attr, int *kind)
 370 {
 371   *kind = PTHREAD_MUTEX_RECURSIVE_NP;
 372   return 0;
 373 }
 374 strong_alias(__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np);
 375
 376 int __pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind)
 377 {
 378   return 0;
 379 }
 380 strong_alias(__pthread_mutexattr_settype, pthread_mutexattr_settype);
 381
 382 int __pthread_mutexattr_gettype(pthread_mutexattr_t *attr, int *kind)
 383 {
 384   *kind = PTHREAD_MUTEX_RECURSIVE_NP;
 385   return 0;
 386 }
 387 strong_alias(__pthread_mutexattr_gettype, pthread_mutexattr_gettype);
 388
 389
 390 /***** THREAD-SPECIFIC VARIABLES (KEYS) *****/
 391
 392 int __pthread_key_create(pthread_key_t *key, void (*destr_function)(void *))
 393 {
 394   static LONG keycnt = FIRST_KEY;
 395   *key = InterlockedExchangeAdd(&keycnt, 1);
 396   return 0;
 397 }
 398 strong_alias(__pthread_key_create, pthread_key_create);
 399
 400 int __pthread_key_delete(pthread_key_t key)
 401 {
 402   return 0;
 403 }
 404 strong_alias(__pthread_key_delete, pthread_key_delete);
 405
 406 int __pthread_setspecific(pthread_key_t key, const void *pointer)
 407 {
 408   TEB *teb = NtCurrentTeb();
 409   if (!teb->pthread_data) {
 410     teb->pthread_data = calloc(MAX_KEYS,sizeof(key_data));
 411   }
 412   ((key_data*)(teb->pthread_data))[key] = pointer;
 413   return 0;
 414 }
 415 strong_alias(__pthread_setspecific, pthread_setspecific);
 416
 417 void *__pthread_getspecific(pthread_key_t key)
 418 {
 419   TEB *teb = NtCurrentTeb();
 420   if (!teb) return NULL;
 421   if (!teb->pthread_data) return NULL;
 422   return (void *)(((key_data*)(teb->pthread_data))[key]);
 423 }
 424 strong_alias(__pthread_getspecific, pthread_getspecific);
 425
 426
 427 /***** "EXCEPTION" FRAMES *****/
 428 /* not implemented right now */
 429
 430 void _pthread_cleanup_push(struct _pthread_cleanup_buffer *buffer, void (*routine)(void *), void *arg)
 431 {
 432   ((wine_cleanup)buffer)->routine = routine;
 433   ((wine_cleanup)buffer)->arg = arg;
 434 }
 435
 436 void _pthread_cleanup_pop(struct _pthread_cleanup_buffer *buffer, int execute)
 437 {
 438   if (execute) (*(((wine_cleanup)buffer)->routine))(((wine_cleanup)buffer)->arg);
 439 }
 440
 441 void _pthread_cleanup_push_defer(struct _pthread_cleanup_buffer *buffer, void (*routine)(void *), void *arg)
 442 {
 443   _pthread_cleanup_push(buffer, routine, arg);
 444 }
 445
 446 void _pthread_cleanup_pop_restore(struct _pthread_cleanup_buffer *buffer, int execute)
 447 {
 448   _pthread_cleanup_pop(buffer, execute);
 449 }
 450
 451
 452 /***** CONDITIONS *****/
 453 /* not implemented right now */
 454
 455 int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *cond_attr)
 456 {
 457   P_OUTPUT("FIXME:pthread_cond_init\n");
 458   return 0;
 459 }
 460
 461 int pthread_cond_destroy(pthread_cond_t *cond)
 462 {
 463   P_OUTPUT("FIXME:pthread_cond_destroy\n");
 464   return 0;
 465 }
 466
 467 int pthread_cond_signal(pthread_cond_t *cond)
 468 {
 469   P_OUTPUT("FIXME:pthread_cond_signal\n");
 470   return 0;
 471 }
 472
 473 int pthread_cond_broadcast(pthread_cond_t *cond)
 474 {
 475   P_OUTPUT("FIXME:pthread_cond_broadcast\n");
 476   return 0;
 477 }
 478
 479 int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
 480 {
 481   P_OUTPUT("FIXME:pthread_cond_wait\n");
 482   return 0;
 483 }
 484
 485 int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, const struct timespec *abstime)
 486 {
 487   P_OUTPUT("FIXME:pthread_cond_timedwait\n");
 488   return 0;
 489 }
 490
 491 /**** CONDITION ATTRIBUTES *****/
 492 /* not implemented right now */
 493
 494 int pthread_condattr_init(pthread_condattr_t *attr)
 495 {
 496   return 0;
 497 }
 498
 499 int pthread_condattr_destroy(pthread_condattr_t *attr)
 500 {
 501   return 0;
 502 }
 503
 504 #if (__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 2)
 505 /***** READ-WRITE LOCKS *****/
 506
 507 static void rwlock_real_init(pthread_rwlock_t *rwlock)
 508 {
 509   RTL_RWLOCK *lock = HeapAlloc(GetProcessHeap(), 0, sizeof(RTL_RWLOCK));
 510   RtlInitializeResource(lock);
 511
 512   if (InterlockedCompareExchangePointer((void**)&(((wine_rwlock)rwlock)->lock),lock,NULL) != NULL) {
 513     /* too late, some other thread already did it */
 514     RtlDeleteResource(lock);
 515     HeapFree(GetProcessHeap(), 0, lock);
 516   }
 517 }
 518
 519 int __pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *rwlock_attr)
 520 {
 521   ((wine_rwlock)rwlock)->lock = NULL;
 522   return 0;
 523 }
 524 strong_alias(__pthread_rwlock_init, pthread_rwlock_init);
 525
 526 int __pthread_rwlock_destroy(pthread_rwlock_t *rwlock)
 527 {
 528   if (!((wine_rwlock)rwlock)->lock) return 0;
 529   RtlDeleteResource(((wine_rwlock)rwlock)->lock);
 530   HeapFree(GetProcessHeap(), 0, ((wine_rwlock)rwlock)->lock);
 531   return 0;
 532 }
 533 strong_alias(__pthread_rwlock_destroy, pthread_rwlock_destroy);
 534
 535 int __pthread_rwlock_rdlock(pthread_rwlock_t *rwlock)
 536 {
 537   if (!init_done) return 0;
 538   if (!((wine_rwlock)rwlock)->lock)
 539     rwlock_real_init( rwlock );
 540
 541   while(TRUE)
 542     if (RtlAcquireResourceShared(((wine_rwlock)rwlock)->lock, TRUE))
 543       return 0;
 544 }
 545 strong_alias(__pthread_rwlock_rdlock, pthread_rwlock_rdlock);
 546
 547 int __pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock)
 548 {
 549   if (!init_done) return 0;
 550   if (!((wine_rwlock)rwlock)->lock)
 551     rwlock_real_init( rwlock );
 552
 553   if (!RtlAcquireResourceShared(((wine_rwlock)rwlock)->lock, FALSE)) {
 554     errno = EBUSY;
 555     return -1;
 556   }
 557   return 0;
 558 }
 559 strong_alias(__pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock);
 560
 561 int __pthread_rwlock_wrlock(pthread_rwlock_t *rwlock)
 562 {
 563   if (!init_done) return 0;
 564   if (!((wine_rwlock)rwlock)->lock)
 565     rwlock_real_init( rwlock );
 566
 567   while(TRUE)
 568     if (RtlAcquireResourceExclusive(((wine_rwlock)rwlock)->lock, TRUE))
 569       return 0;
 570 }
 571 strong_alias(__pthread_rwlock_wrlock, pthread_rwlock_wrlock);
 572
 573 int __pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock)
 574 {
 575   if (!init_done) return 0;
 576   if (!((wine_rwlock)rwlock)->lock)
 577     rwlock_real_init( rwlock );
 578
 579   if (!RtlAcquireResourceExclusive(((wine_rwlock)rwlock)->lock, FALSE)) {
 580     errno = EBUSY;
 581     return -1;
 582   }
 583   return 0;
 584 }
 585 strong_alias(__pthread_rwlock_trywrlock, pthread_rwlock_trywrlock);
 586
 587 int __pthread_rwlock_unlock(pthread_rwlock_t *rwlock)
 588 {
 589   if (!((wine_rwlock)rwlock)->lock) return 0;
 590   RtlReleaseResource( ((wine_rwlock)rwlock)->lock );
 591   return 0;
 592 }
 593 strong_alias(__pthread_rwlock_unlock, pthread_rwlock_unlock);
 594
 595 /**** READ-WRITE LOCK ATTRIBUTES *****/
 596 /* not implemented right now */
 597
 598 int pthread_rwlockattr_init(pthread_rwlockattr_t *attr)
 599 {
 600   return 0;
 601 }
 602
 603 int __pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr)
 604 {
 605   return 0;
 606 }
 607 strong_alias(__pthread_rwlockattr_destroy, pthread_rwlockattr_destroy);
 608
 609 int pthread_rwlockattr_getkind_np(const pthread_rwlockattr_t *attr, int *pref)
 610 {
 611   *pref = 0;
 612   return 0;
 613 }
 614
 615 int pthread_rwlockattr_setkind_np(pthread_rwlockattr_t *attr, int pref)
 616 {
 617   return 0;
 618 }
 619 #endif /* glibc 2.2 */
 620
 621 /***** MISC *****/
 622
 623 pthread_t pthread_self(void)
 624 {
 625   return (pthread_t)GetCurrentThreadId();
 626 }
 627
 628 int pthread_equal(pthread_t thread1, pthread_t thread2)
 629 {
 630   return (DWORD)thread1 == (DWORD)thread2;
 631 }
 632
 633 void pthread_exit(void *retval)
 634 {
 635   /* FIXME: pthread cleanup */
 636   ExitThread((DWORD)retval);
 637 }
 638
 639 int pthread_setcanceltype(int type, int *oldtype)
 640 {
 641   if (oldtype) *oldtype = PTHREAD_CANCEL_ASYNCHRONOUS;
 642   return 0;
 643 }
 644
 645 /***** ANTI-OVERRIDES *****/
 646 /* pthreads tries to override these, point them back to libc */
 647
 648 int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
 649 {
 650     if (!libc_sigaction)
 651     {
 652         libc_sigaction = dlsym( RTLD_NEXT, "sigaction" );
 653         assert( libc_sigaction );
 654     }
 655     return libc_sigaction(signum, act, oldact);
 656 }
 657
 658 #else /* __GLIBC__ */
 659
 660 void PTHREAD_init_done(void)
 661 {
 662 }
 663
 664 #endif /* __GLIBC__ */