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