gcc/gthr-posix95.h

   1 /* Threads compatibility routines for libgcc2 and libobjc.  */
   2 /* Compile this one with gcc.  */
   3 /* Copyright (C) 2004, 2005 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, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, 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 /* Some implementations of <pthread.h> require this to be defined.  */
  38 #ifndef _REENTRANT
  39 #define _REENTRANT 1
  40 #endif
  41
  42 #include <pthread.h>
  43 #include <unistd.h>
  44
  45 typedef pthread_key_t __gthread_key_t;
  46 typedef pthread_once_t __gthread_once_t;
  47 typedef pthread_mutex_t __gthread_mutex_t;
  48
  49 typedef struct {
  50   long depth;
  51   pthread_t owner;
  52   pthread_mutex_t actual;
  53 } __gthread_recursive_mutex_t;
  54
  55 #define __GTHREAD_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER
  56 #define __GTHREAD_ONCE_INIT PTHREAD_ONCE_INIT
  57 #define __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION __gthread_recursive_mutex_init_function
  58
  59 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
  60 # define __gthrw(name) \
  61   extern __typeof(name) __gthrw_ ## name __attribute__ ((__weakref__(#name)))
  62 #else
  63 # define __gthrw_asmname(cname) __gthrw_asmnamep (__USER_LABEL_PREFIX__, cname)
  64 # define __gthrw_asmnamep(prefix, cname) __gthrw_string (prefix) cname
  65 # define __gthrw_string(x) #x
  66 # define __gthrw(name) \
  67   extern __typeof(name) __gthrw_ ## name __asm (__gthrw_asmname (#name))
  68 #endif
  69
  70 __gthrw(pthread_once);
  71 __gthrw(pthread_key_create);
  72 __gthrw(pthread_key_delete);
  73 __gthrw(pthread_getspecific);
  74 __gthrw(pthread_setspecific);
  75 __gthrw(pthread_create);
  76 __gthrw(pthread_cancel);
  77 __gthrw(pthread_self);
  78
  79 __gthrw(pthread_mutex_lock);
  80 __gthrw(pthread_mutex_trylock);
  81 __gthrw(pthread_mutex_unlock);
  82 __gthrw(pthread_mutexattr_init);
  83 __gthrw(pthread_mutexattr_destroy);
  84
  85 __gthrw(pthread_mutex_init);
  86
  87 #if defined(_LIBOBJC) || defined(_LIBOBJC_WEAK)
  88 /* Objective-C.  */
  89 __gthrw(pthread_cond_broadcast);
  90 __gthrw(pthread_cond_destroy);
  91 __gthrw(pthread_cond_init);
  92 __gthrw(pthread_cond_signal);
  93 __gthrw(pthread_cond_wait);
  94 __gthrw(pthread_exit);
  95 __gthrw(pthread_mutex_destroy);
  96 #ifdef _POSIX_PRIORITY_SCHEDULING
  97 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
  98 __gthrw(sched_get_priority_max);
  99 __gthrw(sched_get_priority_min);
 100 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
 101 #endif /* _POSIX_PRIORITY_SCHEDULING */
 102 __gthrw(sched_yield);
 103 __gthrw(pthread_attr_destroy);
 104 __gthrw(pthread_attr_init);
 105 __gthrw(pthread_attr_setdetachstate);
 106 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
 107 __gthrw(pthread_getschedparam);
 108 __gthrw(pthread_setschedparam);
 109 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
 110 #endif /* _LIBOBJC || _LIBOBJC_WEAK */
 111
 112 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
 113
 114 static inline int
 115 __gthread_active_p (void)
 116 {
 117   static void *const __gthread_active_ptr
 118     = __extension__ (void *) &__gthrw_pthread_cancel;
 119   return __gthread_active_ptr != 0;
 120 }
 121
 122 #else /* not SUPPORTS_WEAK */
 123
 124 static inline int
 125 __gthread_active_p (void)
 126 {
 127   return 1;
 128 }
 129
 130 #endif /* SUPPORTS_WEAK */
 131
 132 #ifdef _LIBOBJC
 133
 134 /* This is the config.h file in libobjc/ */
 135 #include <config.h>
 136
 137 #ifdef HAVE_SCHED_H
 138 # include <sched.h>
 139 #endif
 140
 141 /* Key structure for maintaining thread specific storage */
 142 static pthread_key_t _objc_thread_storage;
 143 static pthread_attr_t _objc_thread_attribs;
 144
 145 /* Thread local storage for a single thread */
 146 static void *thread_local_storage = NULL;
 147
 148 /* Backend initialization functions */
 149
 150 /* Initialize the threads subsystem.  */
 151 static inline int
 152 __gthread_objc_init_thread_system (void)
 153 {
 154   if (__gthread_active_p ())
 155     {
 156       /* Initialize the thread storage key.  */
 157       if (__gthrw_pthread_key_create (&_objc_thread_storage, NULL) == 0)
 158         {
 159           /* The normal default detach state for threads is
 160            * PTHREAD_CREATE_JOINABLE which causes threads to not die
 161            * when you think they should.  */
 162           if (__gthrw_pthread_attr_init (&_objc_thread_attribs) == 0
 163               && __gthrw_pthread_attr_setdetachstate (&_objc_thread_attribs,
 164                                               PTHREAD_CREATE_DETACHED) == 0)
 165             return 0;
 166         }
 167     }
 168
 169   return -1;
 170 }
 171
 172 /* Close the threads subsystem.  */
 173 static inline int
 174 __gthread_objc_close_thread_system (void)
 175 {
 176   if (__gthread_active_p ()
 177       && __gthrw_pthread_key_delete (_objc_thread_storage) == 0
 178       && __gthrw_pthread_attr_destroy (&_objc_thread_attribs) == 0)
 179     return 0;
 180
 181   return -1;
 182 }
 183
 184 /* Backend thread functions */
 185
 186 /* Create a new thread of execution.  */
 187 static inline objc_thread_t
 188 __gthread_objc_thread_detach (void (*func)(void *), void *arg)
 189 {
 190   objc_thread_t thread_id;
 191   pthread_t new_thread_handle;
 192
 193   if (!__gthread_active_p ())
 194     return NULL;
 195
 196   if (!(__gthrw_pthread_create (&new_thread_handle, NULL, (void *) func, arg)))
 197     thread_id = (objc_thread_t) new_thread_handle;
 198   else
 199     thread_id = NULL;
 200
 201   return thread_id;
 202 }
 203
 204 /* Set the current thread's priority.  */
 205 static inline int
 206 __gthread_objc_thread_set_priority (int priority)
 207 {
 208   if (!__gthread_active_p ())
 209     return -1;
 210   else
 211     {
 212 #ifdef _POSIX_PRIORITY_SCHEDULING
 213 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
 214       pthread_t thread_id = __gthrw_pthread_self ();
 215       int policy;
 216       struct sched_param params;
 217       int priority_min, priority_max;
 218
 219       if (__gthrw_pthread_getschedparam (thread_id, &policy, &params) == 0)
 220         {
 221           if ((priority_max = __gthrw_sched_get_priority_max (policy)) == -1)
 222             return -1;
 223
 224           if ((priority_min = __gthrw_sched_get_priority_min (policy)) == -1)
 225             return -1;
 226
 227           if (priority > priority_max)
 228             priority = priority_max;
 229           else if (priority < priority_min)
 230             priority = priority_min;
 231           params.sched_priority = priority;
 232
 233           /*
 234            * The solaris 7 and several other man pages incorrectly state that
 235            * this should be a pointer to policy but pthread.h is universally
 236            * at odds with this.
 237            */
 238           if (__gthrw_pthread_setschedparam (thread_id, policy, &params) == 0)
 239             return 0;
 240         }
 241 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
 242 #endif /* _POSIX_PRIORITY_SCHEDULING */
 243       return -1;
 244     }
 245 }
 246
 247 /* Return the current thread's priority.  */
 248 static inline int
 249 __gthread_objc_thread_get_priority (void)
 250 {
 251 #ifdef _POSIX_PRIORITY_SCHEDULING
 252 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
 253   if (__gthread_active_p ())
 254     {
 255       int policy;
 256       struct sched_param params;
 257
 258       if (__gthrw_pthread_getschedparam (__gthrw_pthread_self (), &policy, &params) == 0)
 259         return params.sched_priority;
 260       else
 261         return -1;
 262     }
 263   else
 264 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
 265 #endif /* _POSIX_PRIORITY_SCHEDULING */
 266     return OBJC_THREAD_INTERACTIVE_PRIORITY;
 267 }
 268
 269 /* Yield our process time to another thread.  */
 270 static inline void
 271 __gthread_objc_thread_yield (void)
 272 {
 273   if (__gthread_active_p ())
 274     __gthrw_sched_yield ();
 275 }
 276
 277 /* Terminate the current thread.  */
 278 static inline int
 279 __gthread_objc_thread_exit (void)
 280 {
 281   if (__gthread_active_p ())
 282     /* exit the thread */
 283     __gthrw_pthread_exit (&__objc_thread_exit_status);
 284
 285   /* Failed if we reached here */
 286   return -1;
 287 }
 288
 289 /* Returns an integer value which uniquely describes a thread.  */
 290 static inline objc_thread_t
 291 __gthread_objc_thread_id (void)
 292 {
 293   if (__gthread_active_p ())
 294     return (objc_thread_t) __gthrw_pthread_self ();
 295   else
 296     return (objc_thread_t) 1;
 297 }
 298
 299 /* Sets the thread's local storage pointer.  */
 300 static inline int
 301 __gthread_objc_thread_set_data (void *value)
 302 {
 303   if (__gthread_active_p ())
 304     return __gthrw_pthread_setspecific (_objc_thread_storage, value);
 305   else
 306     {
 307       thread_local_storage = value;
 308       return 0;
 309     }
 310 }
 311
 312 /* Returns the thread's local storage pointer.  */
 313 static inline void *
 314 __gthread_objc_thread_get_data (void)
 315 {
 316   if (__gthread_active_p ())
 317     return __gthrw_pthread_getspecific (_objc_thread_storage);
 318   else
 319     return thread_local_storage;
 320 }
 321
 322 /* Backend mutex functions */
 323
 324 /* Allocate a mutex.  */
 325 static inline int
 326 __gthread_objc_mutex_allocate (objc_mutex_t mutex)
 327 {
 328   if (__gthread_active_p ())
 329     {
 330       mutex->backend = objc_malloc (sizeof (pthread_mutex_t));
 331
 332       if (__gthrw_pthread_mutex_init ((pthread_mutex_t *) mutex->backend, NULL))
 333         {
 334           objc_free (mutex->backend);
 335           mutex->backend = NULL;
 336           return -1;
 337         }
 338     }
 339
 340   return 0;
 341 }
 342
 343 /* Deallocate a mutex.  */
 344 static inline int
 345 __gthread_objc_mutex_deallocate (objc_mutex_t mutex)
 346 {
 347   if (__gthread_active_p ())
 348     {
 349       int count;
 350
 351       /*
 352        * Posix Threads specifically require that the thread be unlocked
 353        * for __gthrw_pthread_mutex_destroy to work.
 354        */
 355
 356       do
 357         {
 358           count = __gthrw_pthread_mutex_unlock ((pthread_mutex_t *) mutex->backend);
 359           if (count < 0)
 360             return -1;
 361         }
 362       while (count);
 363
 364       if (__gthrw_pthread_mutex_destroy ((pthread_mutex_t *) mutex->backend))
 365         return -1;
 366
 367       objc_free (mutex->backend);
 368       mutex->backend = NULL;
 369     }
 370   return 0;
 371 }
 372
 373 /* Grab a lock on a mutex.  */
 374 static inline int
 375 __gthread_objc_mutex_lock (objc_mutex_t mutex)
 376 {
 377   if (__gthread_active_p ()
 378       && __gthrw_pthread_mutex_lock ((pthread_mutex_t *) mutex->backend) != 0)
 379     {
 380       return -1;
 381     }
 382
 383   return 0;
 384 }
 385
 386 /* Try to grab a lock on a mutex.  */
 387 static inline int
 388 __gthread_objc_mutex_trylock (objc_mutex_t mutex)
 389 {
 390   if (__gthread_active_p ()
 391       && __gthrw_pthread_mutex_trylock ((pthread_mutex_t *) mutex->backend) != 0)
 392     {
 393       return -1;
 394     }
 395
 396   return 0;
 397 }
 398
 399 /* Unlock the mutex */
 400 static inline int
 401 __gthread_objc_mutex_unlock (objc_mutex_t mutex)
 402 {
 403   if (__gthread_active_p ()
 404       && __gthrw_pthread_mutex_unlock ((pthread_mutex_t *) mutex->backend) != 0)
 405     {
 406       return -1;
 407     }
 408
 409   return 0;
 410 }
 411
 412 /* Backend condition mutex functions */
 413
 414 /* Allocate a condition.  */
 415 static inline int
 416 __gthread_objc_condition_allocate (objc_condition_t condition)
 417 {
 418   if (__gthread_active_p ())
 419     {
 420       condition->backend = objc_malloc (sizeof (pthread_cond_t));
 421
 422       if (__gthrw_pthread_cond_init ((pthread_cond_t *) condition->backend, NULL))
 423         {
 424           objc_free (condition->backend);
 425           condition->backend = NULL;
 426           return -1;
 427         }
 428     }
 429
 430   return 0;
 431 }
 432
 433 /* Deallocate a condition.  */
 434 static inline int
 435 __gthread_objc_condition_deallocate (objc_condition_t condition)
 436 {
 437   if (__gthread_active_p ())
 438     {
 439       if (__gthrw_pthread_cond_destroy ((pthread_cond_t *) condition->backend))
 440         return -1;
 441
 442       objc_free (condition->backend);
 443       condition->backend = NULL;
 444     }
 445   return 0;
 446 }
 447
 448 /* Wait on the condition */
 449 static inline int
 450 __gthread_objc_condition_wait (objc_condition_t condition, objc_mutex_t mutex)
 451 {
 452   if (__gthread_active_p ())
 453     return __gthrw_pthread_cond_wait ((pthread_cond_t *) condition->backend,
 454                               (pthread_mutex_t *) mutex->backend);
 455   else
 456     return 0;
 457 }
 458
 459 /* Wake up all threads waiting on this condition.  */
 460 static inline int
 461 __gthread_objc_condition_broadcast (objc_condition_t condition)
 462 {
 463   if (__gthread_active_p ())
 464     return __gthrw_pthread_cond_broadcast ((pthread_cond_t *) condition->backend);
 465   else
 466     return 0;
 467 }
 468
 469 /* Wake up one thread waiting on this condition.  */
 470 static inline int
 471 __gthread_objc_condition_signal (objc_condition_t condition)
 472 {
 473   if (__gthread_active_p ())
 474     return __gthrw_pthread_cond_signal ((pthread_cond_t *) condition->backend);
 475   else
 476     return 0;
 477 }
 478
 479 #else /* _LIBOBJC */
 480
 481 static inline int
 482 __gthread_once (__gthread_once_t *once, void (*func) (void))
 483 {
 484   if (__gthread_active_p ())
 485     return __gthrw_pthread_once (once, func);
 486   else
 487     return -1;
 488 }
 489
 490 static inline int
 491 __gthread_key_create (__gthread_key_t *key, void (*dtor) (void *))
 492 {
 493   return __gthrw_pthread_key_create (key, dtor);
 494 }
 495
 496 static inline int
 497 __gthread_key_delete (__gthread_key_t key)
 498 {
 499   return __gthrw_pthread_key_delete (key);
 500 }
 501
 502 static inline void *
 503 __gthread_getspecific (__gthread_key_t key)
 504 {
 505   return __gthrw_pthread_getspecific (key);
 506 }
 507
 508 static inline int
 509 __gthread_setspecific (__gthread_key_t key, const void *ptr)
 510 {
 511   return __gthrw_pthread_setspecific (key, ptr);
 512 }
 513
 514 static inline int
 515 __gthread_mutex_lock (__gthread_mutex_t *mutex)
 516 {
 517   if (__gthread_active_p ())
 518     return __gthrw_pthread_mutex_lock (mutex);
 519   else
 520     return 0;
 521 }
 522
 523 static inline int
 524 __gthread_mutex_trylock (__gthread_mutex_t *mutex)
 525 {
 526   if (__gthread_active_p ())
 527     return __gthrw_pthread_mutex_trylock (mutex);
 528   else
 529     return 0;
 530 }
 531
 532 static inline int
 533 __gthread_mutex_unlock (__gthread_mutex_t *mutex)
 534 {
 535   if (__gthread_active_p ())
 536     return __gthrw_pthread_mutex_unlock (mutex);
 537   else
 538     return 0;
 539 }
 540
 541 static inline int
 542 __gthread_recursive_mutex_init_function (__gthread_recursive_mutex_t *mutex)
 543 {
 544   mutex->depth = 0;
 545   mutex->owner = (pthread_t) 0;
 546   return __gthrw_pthread_mutex_init (&mutex->actual, NULL);
 547 }
 548
 549 static inline int
 550 __gthread_recursive_mutex_lock (__gthread_recursive_mutex_t *mutex)
 551 {
 552   if (__gthread_active_p ())
 553     {
 554       pthread_t me = __gthrw_pthread_self ();
 555
 556       if (mutex->owner != me)
 557         {
 558           __gthrw_pthread_mutex_lock (&mutex->actual);
 559           mutex->owner = me;
 560         }
 561
 562       mutex->depth++;
 563     }
 564   return 0;
 565 }
 566
 567 static inline int
 568 __gthread_recursive_mutex_trylock (__gthread_recursive_mutex_t *mutex)
 569 {
 570   if (__gthread_active_p ())
 571     {
 572       pthread_t me = __gthrw_pthread_self ();
 573
 574       if (mutex->owner != me)
 575         {
 576           if (__gthrw_pthread_mutex_trylock (&mutex->actual))
 577             return 1;
 578           mutex->owner = me;
 579         }
 580
 581       mutex->depth++;
 582     }
 583   return 0;
 584 }
 585
 586 static inline int
 587 __gthread_recursive_mutex_unlock (__gthread_recursive_mutex_t *mutex)
 588 {
 589   if (__gthread_active_p ())
 590     {
 591       if (--mutex->depth == 0)
 592         {
 593            mutex->owner = (pthread_t) 0;
 594            __gthrw_pthread_mutex_unlock (&mutex->actual);
 595         }
 596     }
 597   return 0;
 598 }
 599
 600 #endif /* _LIBOBJC */
 601
 602 #endif /* ! GCC_GTHR_POSIX_H */