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