gcc/gthr-posix.h

   1 /* Threads compatibility routines for libgcc2 and libobjc.  */
   2 /* Compile this one with gcc.  */
   3 /* Copyright (C) 1997, 1999, 2000, 2001 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 /* As a special exception, if you link this library with other files,
  23    some of which are compiled with GCC, to produce an executable,
  24    this library does not by itself cause the resulting executable
  25    to be covered by the GNU General Public License.
  26    This exception does not however invalidate any other reasons why
  27    the executable file might be covered by the GNU General Public License.  */
  28
  29 #ifndef GCC_GTHR_POSIX_H
  30 #define GCC_GTHR_POSIX_H
  31
  32 /* POSIX threads specific definitions.
  33    Easy, since the interface is just one-to-one mapping.  */
  34
  35 #define __GTHREADS 1
  36
  37 #include <pthread.h>
  38
  39 typedef pthread_key_t __gthread_key_t;
  40 typedef pthread_once_t __gthread_once_t;
  41 typedef pthread_mutex_t __gthread_mutex_t;
  42
  43 #define __GTHREAD_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER
  44 #define __GTHREAD_ONCE_INIT PTHREAD_ONCE_INIT
  45
  46 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
  47
  48 #pragma weak pthread_once
  49 #pragma weak pthread_key_create
  50 #pragma weak pthread_key_delete
  51 #pragma weak pthread_getspecific
  52 #pragma weak pthread_setspecific
  53 #pragma weak pthread_create
  54
  55 #pragma weak pthread_mutex_lock
  56 #pragma weak pthread_mutex_trylock
  57 #pragma weak pthread_mutex_unlock
  58
  59 #ifdef _LIBOBJC
  60 /* Objective C.  */
  61 #pragma weak pthread_cond_broadcast
  62 #pragma weak pthread_cond_destroy
  63 #pragma weak pthread_cond_init
  64 #pragma weak pthread_cond_signal
  65 #pragma weak pthread_cond_wait
  66 #pragma weak pthread_exit
  67 #pragma weak pthread_mutex_init
  68 #pragma weak pthread_mutex_destroy
  69 #pragma weak pthread_self
  70 #pragma weak sched_get_priority_max
  71 #pragma weak sched_get_priority_min
  72 #pragma weak sched_yield
  73 #pragma weak pthread_attr_destroy
  74 #pragma weak pthread_attr_init
  75 #pragma weak pthread_attr_setdetachstate
  76 #pragma weak pthread_getschedparam
  77 #pragma weak pthread_setschedparam
  78 #endif
  79
  80 static inline int
  81 __gthread_active_p (void)
  82 {
  83   static void *const __gthread_active_ptr = (void *) &pthread_create;
  84   return __gthread_active_ptr != 0;
  85 }
  86
  87 #else /* not SUPPORTS_WEAK */
  88
  89 static inline int
  90 __gthread_active_p (void)
  91 {
  92   return 1;
  93 }
  94
  95 #endif /* SUPPORTS_WEAK */
  96
  97 #ifdef _LIBOBJC
  98
  99 /* This is the config.h file in libobjc/ */
 100 #include <config.h>
 101
 102 #ifdef HAVE_SCHED_H
 103 # include <sched.h>
 104 #endif
 105
 106 /* Key structure for maintaining thread specific storage */
 107 static pthread_key_t _objc_thread_storage;
 108 static pthread_attr_t _objc_thread_attribs;
 109
 110 /* Thread local storage for a single thread */
 111 static void *thread_local_storage = NULL;
 112
 113 /* Backend initialization functions */
 114
 115 /* Initialize the threads subsystem.  */
 116 static inline int
 117 __gthread_objc_init_thread_system(void)
 118 {
 119   if (__gthread_active_p ())
 120     {
 121       /* Initialize the thread storage key */
 122       if (pthread_key_create(&_objc_thread_storage, NULL) == 0)
 123         {
 124           /* The normal default detach state for threads is
 125            * PTHREAD_CREATE_JOINABLE which causes threads to not die
 126            * when you think they should.  */
 127           if (pthread_attr_init(&_objc_thread_attribs) == 0
 128               && pthread_attr_setdetachstate(&_objc_thread_attribs,
 129                                              PTHREAD_CREATE_DETACHED) == 0)
 130             return 0;
 131         }
 132     }
 133
 134   return -1;
 135 }
 136
 137 /* Close the threads subsystem.  */
 138 static inline int
 139 __gthread_objc_close_thread_system(void)
 140 {
 141   if (__gthread_active_p ()
 142       && pthread_key_delete(_objc_thread_storage) == 0
 143       && pthread_attr_destroy(&_objc_thread_attribs) == 0)
 144     return 0;
 145
 146   return -1;
 147 }
 148
 149 /* Backend thread functions */
 150
 151 /* Create a new thread of execution.  */
 152 static inline objc_thread_t
 153 __gthread_objc_thread_detach(void (*func)(void *), void *arg)
 154 {
 155   objc_thread_t thread_id;
 156   pthread_t new_thread_handle;
 157
 158   if (!__gthread_active_p ())
 159     return NULL;
 160
 161   if ( !(pthread_create(&new_thread_handle, NULL, (void *)func, arg)) )
 162     thread_id = (objc_thread_t) new_thread_handle;
 163   else
 164     thread_id = NULL;
 165
 166   return thread_id;
 167 }
 168
 169 /* Set the current thread's priority.  */
 170 static inline int
 171 __gthread_objc_thread_set_priority(int priority)
 172 {
 173   if (!__gthread_active_p())
 174     return -1;
 175   else {
 176     pthread_t thread_id = pthread_self();
 177     int policy;
 178     struct sched_param params;
 179     int priority_min, priority_max;
 180
 181     if (pthread_getschedparam(thread_id, &policy, &params) == 0)
 182       {
 183         if ((priority_max = sched_get_priority_max(policy)) != 0)
 184           return -1;
 185
 186         if ((priority_min = sched_get_priority_min(policy)) != 0)
 187           return -1;
 188
 189         if (priority > priority_max)
 190           priority = priority_max;
 191         else if (priority < priority_min)
 192           priority = priority_min;
 193         params.sched_priority = priority;
 194
 195         /*
 196          * The solaris 7 and several other man pages incorrectly state that
 197          * this should be a pointer to policy but pthread.h is universally
 198          * at odds with this.
 199          */
 200         if (pthread_setschedparam(thread_id, policy, &params) == 0)
 201           return 0;
 202       }
 203     return -1;
 204   }
 205 }
 206
 207 /* Return the current thread's priority.  */
 208 static inline int
 209 __gthread_objc_thread_get_priority(void)
 210 {
 211   if (__gthread_active_p ())
 212     {
 213       int policy;
 214       struct sched_param params;
 215
 216       if (pthread_getschedparam(pthread_self(), &policy, &params) == 0)
 217         return params.sched_priority;
 218       else
 219         return -1;
 220     }
 221   else
 222     return OBJC_THREAD_INTERACTIVE_PRIORITY;
 223 }
 224
 225 /* Yield our process time to another thread.  */
 226 static inline void
 227 __gthread_objc_thread_yield(void)
 228 {
 229   if (__gthread_active_p ())
 230     sched_yield();
 231 }
 232
 233 /* Terminate the current thread.  */
 234 static inline int
 235 __gthread_objc_thread_exit(void)
 236 {
 237   if (__gthread_active_p ())
 238     /* exit the thread */
 239     pthread_exit(&__objc_thread_exit_status);
 240
 241   /* Failed if we reached here */
 242   return -1;
 243 }
 244
 245 /* Returns an integer value which uniquely describes a thread.  */
 246 static inline objc_thread_t
 247 __gthread_objc_thread_id(void)
 248 {
 249   if (__gthread_active_p ())
 250     return (objc_thread_t) pthread_self();
 251   else
 252     return (objc_thread_t) 1;
 253 }
 254
 255 /* Sets the thread's local storage pointer.  */
 256 static inline int
 257 __gthread_objc_thread_set_data(void *value)
 258 {
 259   if (__gthread_active_p ())
 260     return pthread_setspecific(_objc_thread_storage, value);
 261   else
 262     {
 263       thread_local_storage = value;
 264       return 0;
 265     }
 266 }
 267
 268 /* Returns the thread's local storage pointer.  */
 269 static inline void *
 270 __gthread_objc_thread_get_data(void)
 271 {
 272   if (__gthread_active_p ())
 273     return pthread_getspecific(_objc_thread_storage);
 274   else
 275     return thread_local_storage;
 276 }
 277
 278 /* Backend mutex functions */
 279
 280 /* Allocate a mutex.  */
 281 static inline int
 282 __gthread_objc_mutex_allocate(objc_mutex_t mutex)
 283 {
 284   if (__gthread_active_p ())
 285     {
 286       mutex->backend = objc_malloc(sizeof(pthread_mutex_t));
 287
 288       if (pthread_mutex_init((pthread_mutex_t *)mutex->backend, NULL))
 289         {
 290           objc_free(mutex->backend);
 291           mutex->backend = NULL;
 292           return -1;
 293         }
 294     }
 295
 296   return 0;
 297 }
 298
 299 /* Deallocate a mutex.  */
 300 static inline int
 301 __gthread_objc_mutex_deallocate(objc_mutex_t mutex)
 302 {
 303   if (__gthread_active_p ())
 304     {
 305       int count;
 306
 307       /*
 308        * Posix Threads specifically require that the thread be unlocked
 309        * for pthread_mutex_destroy to work.
 310        */
 311
 312       do
 313         {
 314           count = pthread_mutex_unlock((pthread_mutex_t *)mutex->backend);
 315           if (count < 0)
 316             return -1;
 317         }
 318       while (count);
 319
 320       if (pthread_mutex_destroy((pthread_mutex_t *)mutex->backend))
 321         return -1;
 322
 323       objc_free(mutex->backend);
 324       mutex->backend = NULL;
 325     }
 326   return 0;
 327 }
 328
 329 /* Grab a lock on a mutex.  */
 330 static inline int
 331 __gthread_objc_mutex_lock(objc_mutex_t mutex)
 332 {
 333   if (__gthread_active_p ()
 334       && pthread_mutex_lock((pthread_mutex_t *)mutex->backend) != 0)
 335     {
 336       return -1;
 337     }
 338
 339   return 0;
 340 }
 341
 342 /* Try to grab a lock on a mutex.  */
 343 static inline int
 344 __gthread_objc_mutex_trylock(objc_mutex_t mutex)
 345 {
 346   if (__gthread_active_p ()
 347       && pthread_mutex_trylock((pthread_mutex_t *)mutex->backend) != 0)
 348     {
 349       return -1;
 350     }
 351
 352   return 0;
 353 }
 354
 355 /* Unlock the mutex */
 356 static inline int
 357 __gthread_objc_mutex_unlock(objc_mutex_t mutex)
 358 {
 359   if (__gthread_active_p ()
 360       && pthread_mutex_unlock((pthread_mutex_t *)mutex->backend) != 0)
 361     {
 362       return -1;
 363     }
 364
 365   return 0;
 366 }
 367
 368 /* Backend condition mutex functions */
 369
 370 /* Allocate a condition.  */
 371 static inline int
 372 __gthread_objc_condition_allocate(objc_condition_t condition)
 373 {
 374   if (__gthread_active_p ())
 375     {
 376       condition->backend = objc_malloc(sizeof(pthread_cond_t));
 377
 378       if (pthread_cond_init((pthread_cond_t *)condition->backend, NULL))
 379         {
 380           objc_free(condition->backend);
 381           condition->backend = NULL;
 382           return -1;
 383         }
 384     }
 385
 386   return 0;
 387 }
 388
 389 /* Deallocate a condition.  */
 390 static inline int
 391 __gthread_objc_condition_deallocate(objc_condition_t condition)
 392 {
 393   if (__gthread_active_p ())
 394     {
 395       if (pthread_cond_destroy((pthread_cond_t *)condition->backend))
 396         return -1;
 397
 398       objc_free(condition->backend);
 399       condition->backend = NULL;
 400     }
 401   return 0;
 402 }
 403
 404 /* Wait on the condition */
 405 static inline int
 406 __gthread_objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex)
 407 {
 408   if (__gthread_active_p ())
 409     return pthread_cond_wait((pthread_cond_t *)condition->backend,
 410                            (pthread_mutex_t *)mutex->backend);
 411   else
 412     return 0;
 413 }
 414
 415 /* Wake up all threads waiting on this condition.  */
 416 static inline int
 417 __gthread_objc_condition_broadcast(objc_condition_t condition)
 418 {
 419   if (__gthread_active_p ())
 420     return pthread_cond_broadcast((pthread_cond_t *)condition->backend);
 421   else
 422     return 0;
 423 }
 424
 425 /* Wake up one thread waiting on this condition.  */
 426 static inline int
 427 __gthread_objc_condition_signal(objc_condition_t condition)
 428 {
 429   if (__gthread_active_p ())
 430     return pthread_cond_signal((pthread_cond_t *)condition->backend);
 431   else
 432     return 0;
 433 }
 434
 435 #else /* _LIBOBJC */
 436
 437 static inline int
 438 __gthread_once (__gthread_once_t *once, void (*func) (void))
 439 {
 440   if (__gthread_active_p ())
 441     return pthread_once (once, func);
 442   else
 443     return -1;
 444 }
 445
 446 static inline int
 447 __gthread_key_create (__gthread_key_t *key, void (*dtor) (void *))
 448 {
 449   return pthread_key_create (key, dtor);
 450 }
 451
 452 static inline int
 453 __gthread_key_dtor (__gthread_key_t key, void *ptr)
 454 {
 455   /* Just reset the key value to zero.  */
 456   if (ptr)
 457     return pthread_setspecific (key, 0);
 458   else
 459     return 0;
 460 }
 461
 462 static inline int
 463 __gthread_key_delete (__gthread_key_t key)
 464 {
 465   return pthread_key_delete (key);
 466 }
 467
 468 static inline void *
 469 __gthread_getspecific (__gthread_key_t key)
 470 {
 471   return pthread_getspecific (key);
 472 }
 473
 474 static inline int
 475 __gthread_setspecific (__gthread_key_t key, const void *ptr)
 476 {
 477   return pthread_setspecific (key, ptr);
 478 }
 479
 480 static inline int
 481 __gthread_mutex_lock (__gthread_mutex_t *mutex)
 482 {
 483   if (__gthread_active_p ())
 484     return pthread_mutex_lock (mutex);
 485   else
 486     return 0;
 487 }
 488
 489 static inline int
 490 __gthread_mutex_trylock (__gthread_mutex_t *mutex)
 491 {
 492   if (__gthread_active_p ())
 493     return pthread_mutex_trylock (mutex);
 494   else
 495     return 0;
 496 }
 497
 498 static inline int
 499 __gthread_mutex_unlock (__gthread_mutex_t *mutex)
 500 {
 501   if (__gthread_active_p ())
 502     return pthread_mutex_unlock (mutex);
 503   else
 504     return 0;
 505 }
 506
 507 #endif /* _LIBOBJC */
 508
 509 #endif /* ! GCC_GTHR_POSIX_H */