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, 2002, 2003
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING.  If not, write to the Free
  20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  21 02111-1307, USA.  */
  22
  23 /* As a special exception, if you link this library with other files,
  24    some of which are compiled with GCC, to produce an executable,
  25    this library does not by itself cause the resulting executable
  26    to be covered by the GNU General Public License.
  27    This exception does not however invalidate any other reasons why
  28    the executable file might be covered by the GNU General Public License.  */
  29
  30 #ifndef GCC_GTHR_POSIX_H
  31 #define GCC_GTHR_POSIX_H
  32
  33 /* POSIX threads specific definitions.
  34    Easy, since the interface is just one-to-one mapping.  */
  35
  36 #define __GTHREADS 1
  37
  38 /* Some implementations of <pthread.h> require this to be defined.  */
  39 #ifndef _REENTRANT
  40 #define _REENTRANT 1
  41 #endif
  42
  43 #include <pthread.h>
  44 #include <unistd.h>
  45
  46 typedef pthread_key_t __gthread_key_t;
  47 typedef pthread_once_t __gthread_once_t;
  48 typedef pthread_mutex_t __gthread_mutex_t;
  49
  50 #define __GTHREAD_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER
  51 #define __GTHREAD_ONCE_INIT PTHREAD_ONCE_INIT
  52
  53 #if SUPPORTS_WEAK && GTHREAD_USE_WEAK
  54
  55 #pragma weak pthread_once
  56 #pragma weak pthread_key_create
  57 #pragma weak pthread_key_delete
  58 #pragma weak pthread_getspecific
  59 #pragma weak pthread_setspecific
  60 #pragma weak pthread_create
  61
  62 #pragma weak pthread_mutex_lock
  63 #pragma weak pthread_mutex_trylock
  64 #pragma weak pthread_mutex_unlock
  65
  66 #if defined(_LIBOBJC) || defined(_LIBOBJC_WEAK)
  67 /* Objective-C.  */
  68 #pragma weak pthread_cond_broadcast
  69 #pragma weak pthread_cond_destroy
  70 #pragma weak pthread_cond_init
  71 #pragma weak pthread_cond_signal
  72 #pragma weak pthread_cond_wait
  73 #pragma weak pthread_exit
  74 #pragma weak pthread_mutex_init
  75 #pragma weak pthread_mutex_destroy
  76 #pragma weak pthread_self
  77 /* These really should be protected by _POSIX_PRIORITY_SCHEDULING, but
  78    we use them inside a _POSIX_THREAD_PRIORITY_SCHEDULING block.  */
  79 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
  80 #pragma weak sched_get_priority_max
  81 #pragma weak sched_get_priority_min
  82 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
  83 #pragma weak sched_yield
  84 #pragma weak pthread_attr_destroy
  85 #pragma weak pthread_attr_init
  86 #pragma weak pthread_attr_setdetachstate
  87 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
  88 #pragma weak pthread_getschedparam
  89 #pragma weak pthread_setschedparam
  90 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
  91 #endif /* _LIBOBJC || _LIBOBJC_WEAK */
  92
  93 static inline int
  94 __gthread_active_p (void)
  95 {
  96   static void *const __gthread_active_ptr = (void *) &pthread_create;
  97   return __gthread_active_ptr != 0;
  98 }
  99
 100 #else /* not SUPPORTS_WEAK */
 101
 102 static inline int
 103 __gthread_active_p (void)
 104 {
 105   return 1;
 106 }
 107
 108 #endif /* SUPPORTS_WEAK */
 109
 110 #ifdef _LIBOBJC
 111
 112 /* This is the config.h file in libobjc/ */
 113 #include <config.h>
 114
 115 #ifdef HAVE_SCHED_H
 116 # include <sched.h>
 117 #endif
 118
 119 /* Key structure for maintaining thread specific storage */
 120 static pthread_key_t _objc_thread_storage;
 121 static pthread_attr_t _objc_thread_attribs;
 122
 123 /* Thread local storage for a single thread */
 124 static void *thread_local_storage = NULL;
 125
 126 /* Backend initialization functions */
 127
 128 /* Initialize the threads subsystem.  */
 129 static inline int
 130 __gthread_objc_init_thread_system (void)
 131 {
 132   if (__gthread_active_p ())
 133     {
 134       /* Initialize the thread storage key */
 135       if (pthread_key_create (&_objc_thread_storage, NULL) == 0)
 136         {
 137           /* The normal default detach state for threads is
 138            * PTHREAD_CREATE_JOINABLE which causes threads to not die
 139            * when you think they should.  */
 140           if (pthread_attr_init (&_objc_thread_attribs) == 0
 141               && pthread_attr_setdetachstate (&_objc_thread_attribs,
 142                                               PTHREAD_CREATE_DETACHED) == 0)
 143             return 0;
 144         }
 145     }
 146
 147   return -1;
 148 }
 149
 150 /* Close the threads subsystem.  */
 151 static inline int
 152 __gthread_objc_close_thread_system (void)
 153 {
 154   if (__gthread_active_p ()
 155       && pthread_key_delete (_objc_thread_storage) == 0
 156       && pthread_attr_destroy (&_objc_thread_attribs) == 0)
 157     return 0;
 158
 159   return -1;
 160 }
 161
 162 /* Backend thread functions */
 163
 164 /* Create a new thread of execution.  */
 165 static inline objc_thread_t
 166 __gthread_objc_thread_detach (void (*func)(void *), void *arg)
 167 {
 168   objc_thread_t thread_id;
 169   pthread_t new_thread_handle;
 170
 171   if (!__gthread_active_p ())
 172     return NULL;
 173
 174   if (!(pthread_create (&new_thread_handle, NULL, (void *) func, arg)))
 175     thread_id = (objc_thread_t) new_thread_handle;
 176   else
 177     thread_id = NULL;
 178
 179   return thread_id;
 180 }
 181
 182 /* Set the current thread's priority.  */
 183 static inline int
 184 __gthread_objc_thread_set_priority (int priority)
 185 {
 186   if (!__gthread_active_p ())
 187     return -1;
 188   else
 189     {
 190 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
 191       pthread_t thread_id = pthread_self ();
 192       int policy;
 193       struct sched_param params;
 194       int priority_min, priority_max;
 195
 196       if (pthread_getschedparam (thread_id, &policy, &params) == 0)
 197         {
 198           if ((priority_max = sched_get_priority_max (policy)) == -1)
 199             return -1;
 200
 201           if ((priority_min = sched_get_priority_min (policy)) == -1)
 202             return -1;
 203
 204           if (priority > priority_max)
 205             priority = priority_max;
 206           else if (priority < priority_min)
 207             priority = priority_min;
 208           params.sched_priority = priority;
 209
 210           /*
 211            * The solaris 7 and several other man pages incorrectly state that
 212            * this should be a pointer to policy but pthread.h is universally
 213            * at odds with this.
 214            */
 215           if (pthread_setschedparam (thread_id, policy, &params) == 0)
 216             return 0;
 217         }
 218 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
 219       return -1;
 220     }
 221 }
 222
 223 /* Return the current thread's priority.  */
 224 static inline int
 225 __gthread_objc_thread_get_priority (void)
 226 {
 227 #ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
 228   if (__gthread_active_p ())
 229     {
 230       int policy;
 231       struct sched_param params;
 232
 233       if (pthread_getschedparam (pthread_self (), &policy, &params) == 0)
 234         return params.sched_priority;
 235       else
 236         return -1;
 237     }
 238   else
 239 #endif /* _POSIX_THREAD_PRIORITY_SCHEDULING */
 240     return OBJC_THREAD_INTERACTIVE_PRIORITY;
 241 }
 242
 243 /* Yield our process time to another thread.  */
 244 static inline void
 245 __gthread_objc_thread_yield (void)
 246 {
 247   if (__gthread_active_p ())
 248     sched_yield ();
 249 }
 250
 251 /* Terminate the current thread.  */
 252 static inline int
 253 __gthread_objc_thread_exit (void)
 254 {
 255   if (__gthread_active_p ())
 256     /* exit the thread */
 257     pthread_exit (&__objc_thread_exit_status);
 258
 259   /* Failed if we reached here */
 260   return -1;
 261 }
 262
 263 /* Returns an integer value which uniquely describes a thread.  */
 264 static inline objc_thread_t
 265 __gthread_objc_thread_id (void)
 266 {
 267   if (__gthread_active_p ())
 268     return (objc_thread_t) pthread_self ();
 269   else
 270     return (objc_thread_t) 1;
 271 }
 272
 273 /* Sets the thread's local storage pointer.  */
 274 static inline int
 275 __gthread_objc_thread_set_data (void *value)
 276 {
 277   if (__gthread_active_p ())
 278     return pthread_setspecific (_objc_thread_storage, value);
 279   else
 280     {
 281       thread_local_storage = value;
 282       return 0;
 283     }
 284 }
 285
 286 /* Returns the thread's local storage pointer.  */
 287 static inline void *
 288 __gthread_objc_thread_get_data (void)
 289 {
 290   if (__gthread_active_p ())
 291     return pthread_getspecific (_objc_thread_storage);
 292   else
 293     return thread_local_storage;
 294 }
 295
 296 /* Backend mutex functions */
 297
 298 /* Allocate a mutex.  */
 299 static inline int
 300 __gthread_objc_mutex_allocate (objc_mutex_t mutex)
 301 {
 302   if (__gthread_active_p ())
 303     {
 304       mutex->backend = objc_malloc (sizeof (pthread_mutex_t));
 305
 306       if (pthread_mutex_init ((pthread_mutex_t *) mutex->backend, NULL))
 307         {
 308           objc_free (mutex->backend);
 309           mutex->backend = NULL;
 310           return -1;
 311         }
 312     }
 313
 314   return 0;
 315 }
 316
 317 /* Deallocate a mutex.  */
 318 static inline int
 319 __gthread_objc_mutex_deallocate (objc_mutex_t mutex)
 320 {
 321   if (__gthread_active_p ())
 322     {
 323       int count;
 324
 325       /*
 326        * Posix Threads specifically require that the thread be unlocked
 327        * for pthread_mutex_destroy to work.
 328        */
 329
 330       do
 331         {
 332           count = pthread_mutex_unlock ((pthread_mutex_t *) mutex->backend);
 333           if (count < 0)
 334             return -1;
 335         }
 336       while (count);
 337
 338       if (pthread_mutex_destroy ((pthread_mutex_t *) mutex->backend))
 339         return -1;
 340
 341       objc_free (mutex->backend);
 342       mutex->backend = NULL;
 343     }
 344   return 0;
 345 }
 346
 347 /* Grab a lock on a mutex.  */
 348 static inline int
 349 __gthread_objc_mutex_lock (objc_mutex_t mutex)
 350 {
 351   if (__gthread_active_p ()
 352       && pthread_mutex_lock ((pthread_mutex_t *) mutex->backend) != 0)
 353     {
 354       return -1;
 355     }
 356
 357   return 0;
 358 }
 359
 360 /* Try to grab a lock on a mutex.  */
 361 static inline int
 362 __gthread_objc_mutex_trylock (objc_mutex_t mutex)
 363 {
 364   if (__gthread_active_p ()
 365       && pthread_mutex_trylock ((pthread_mutex_t *) mutex->backend) != 0)
 366     {
 367       return -1;
 368     }
 369
 370   return 0;
 371 }
 372
 373 /* Unlock the mutex */
 374 static inline int
 375 __gthread_objc_mutex_unlock (objc_mutex_t mutex)
 376 {
 377   if (__gthread_active_p ()
 378       && pthread_mutex_unlock ((pthread_mutex_t *) mutex->backend) != 0)
 379     {
 380       return -1;
 381     }
 382
 383   return 0;
 384 }
 385
 386 /* Backend condition mutex functions */
 387
 388 /* Allocate a condition.  */
 389 static inline int
 390 __gthread_objc_condition_allocate (objc_condition_t condition)
 391 {
 392   if (__gthread_active_p ())
 393     {
 394       condition->backend = objc_malloc (sizeof (pthread_cond_t));
 395
 396       if (pthread_cond_init ((pthread_cond_t *) condition->backend, NULL))
 397         {
 398           objc_free (condition->backend);
 399           condition->backend = NULL;
 400           return -1;
 401         }
 402     }
 403
 404   return 0;
 405 }
 406
 407 /* Deallocate a condition.  */
 408 static inline int
 409 __gthread_objc_condition_deallocate (objc_condition_t condition)
 410 {
 411   if (__gthread_active_p ())
 412     {
 413       if (pthread_cond_destroy ((pthread_cond_t *) condition->backend))
 414         return -1;
 415
 416       objc_free (condition->backend);
 417       condition->backend = NULL;
 418     }
 419   return 0;
 420 }
 421
 422 /* Wait on the condition */
 423 static inline int
 424 __gthread_objc_condition_wait (objc_condition_t condition, objc_mutex_t mutex)
 425 {
 426   if (__gthread_active_p ())
 427     return pthread_cond_wait ((pthread_cond_t *) condition->backend,
 428                               (pthread_mutex_t *) mutex->backend);
 429   else
 430     return 0;
 431 }
 432
 433 /* Wake up all threads waiting on this condition.  */
 434 static inline int
 435 __gthread_objc_condition_broadcast (objc_condition_t condition)
 436 {
 437   if (__gthread_active_p ())
 438     return pthread_cond_broadcast ((pthread_cond_t *) condition->backend);
 439   else
 440     return 0;
 441 }
 442
 443 /* Wake up one thread waiting on this condition.  */
 444 static inline int
 445 __gthread_objc_condition_signal (objc_condition_t condition)
 446 {
 447   if (__gthread_active_p ())
 448     return pthread_cond_signal ((pthread_cond_t *) condition->backend);
 449   else
 450     return 0;
 451 }
 452
 453 #else /* _LIBOBJC */
 454
 455 static inline int
 456 __gthread_once (__gthread_once_t *once, void (*func) (void))
 457 {
 458   if (__gthread_active_p ())
 459     return pthread_once (once, func);
 460   else
 461     return -1;
 462 }
 463
 464 static inline int
 465 __gthread_key_create (__gthread_key_t *key, void (*dtor) (void *))
 466 {
 467   return pthread_key_create (key, dtor);
 468 }
 469
 470 static inline int
 471 __gthread_key_delete (__gthread_key_t key)
 472 {
 473   return pthread_key_delete (key);
 474 }
 475
 476 static inline void *
 477 __gthread_getspecific (__gthread_key_t key)
 478 {
 479   return pthread_getspecific (key);
 480 }
 481
 482 static inline int
 483 __gthread_setspecific (__gthread_key_t key, const void *ptr)
 484 {
 485   return pthread_setspecific (key, ptr);
 486 }
 487
 488 static inline int
 489 __gthread_mutex_lock (__gthread_mutex_t *mutex)
 490 {
 491   if (__gthread_active_p ())
 492     return pthread_mutex_lock (mutex);
 493   else
 494     return 0;
 495 }
 496
 497 static inline int
 498 __gthread_mutex_trylock (__gthread_mutex_t *mutex)
 499 {
 500   if (__gthread_active_p ())
 501     return pthread_mutex_trylock (mutex);
 502   else
 503     return 0;
 504 }
 505
 506 static inline int
 507 __gthread_mutex_unlock (__gthread_mutex_t *mutex)
 508 {
 509   if (__gthread_active_p ())
 510     return pthread_mutex_unlock (mutex);
 511   else
 512     return 0;
 513 }
 514
 515 #endif /* _LIBOBJC */
 516
 517 #endif /* ! GCC_GTHR_POSIX_H */