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