nptl/sysdeps/pthread/bits/libc-lock.h

   1 /* libc-internal interface for mutex locks.  NPTL version.
   2    Copyright (C) 1996-2003, 2005, 2007 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef _BITS_LIBC_LOCK_H
  21 #define _BITS_LIBC_LOCK_H 1
  22
  23 #include <pthread.h>
  24 #define __need_NULL
  25 #include <stddef.h>
  26
  27
  28 /* Fortunately Linux now has a mean to do locking which is realtime
  29    safe without the aid of the thread library.  We also need no fancy
  30    options like error checking mutexes etc.  We only need simple
  31    locks, maybe recursive.  This can be easily and cheaply implemented
  32    using futexes.  We will use them everywhere except in ld.so since
  33    ld.so might be used on old kernels with a different libc.so.  */
  34 #ifdef _LIBC
  35 # include <lowlevellock.h>
  36 # include <tls.h>
  37 # include <pthread-functions.h>
  38 #endif
  39
  40 /* Mutex type.  */
  41 #if defined _LIBC || defined _IO_MTSAFE_IO
  42 # if (defined NOT_IN_libc && !defined IS_IN_libpthread) || !defined _LIBC
  43 typedef pthread_mutex_t __libc_lock_t;
  44 typedef struct { pthread_mutex_t mutex; } __libc_lock_recursive_t;
  45 # else
  46 typedef int __libc_lock_t;
  47 typedef struct { int lock; int cnt; void *owner; } __libc_lock_recursive_t;
  48 # endif
  49 typedef struct { pthread_mutex_t mutex; } __rtld_lock_recursive_t;
  50 # ifdef __USE_UNIX98
  51 typedef pthread_rwlock_t __libc_rwlock_t;
  52 # else
  53 typedef struct __libc_rwlock_opaque__ __libc_rwlock_t;
  54 # endif
  55 #else
  56 typedef struct __libc_lock_opaque__ __libc_lock_t;
  57 typedef struct __libc_lock_recursive_opaque__ __libc_lock_recursive_t;
  58 typedef struct __libc_rwlock_opaque__ __libc_rwlock_t;
  59 #endif
  60
  61 /* Type for key to thread-specific data.  */
  62 typedef pthread_key_t __libc_key_t;
  63
  64 /* Define a lock variable NAME with storage class CLASS.  The lock must be
  65    initialized with __libc_lock_init before it can be used (or define it
  66    with __libc_lock_define_initialized, below).  Use `extern' for CLASS to
  67    declare a lock defined in another module.  In public structure
  68    definitions you must use a pointer to the lock structure (i.e., NAME
  69    begins with a `*'), because its storage size will not be known outside
  70    of libc.  */
  71 #define __libc_lock_define(CLASS,NAME) \
  72   CLASS __libc_lock_t NAME;
  73 #define __libc_rwlock_define(CLASS,NAME) \
  74   CLASS __libc_rwlock_t NAME;
  75 #define __libc_lock_define_recursive(CLASS,NAME) \
  76   CLASS __libc_lock_recursive_t NAME;
  77 #define __rtld_lock_define_recursive(CLASS,NAME) \
  78   CLASS __rtld_lock_recursive_t NAME;
  79
  80 /* Define an initialized lock variable NAME with storage class CLASS.
  81
  82    For the C library we take a deeper look at the initializer.  For
  83    this implementation all fields are initialized to zero.  Therefore
  84    we don't initialize the variable which allows putting it into the
  85    BSS section.  (Except on PA-RISC and other odd architectures, where
  86    initialized locks must be set to one due to the lack of normal
  87    atomic operations.) */
  88
  89 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
  90 # if LLL_LOCK_INITIALIZER == 0
  91 #  define __libc_lock_define_initialized(CLASS,NAME) \
  92   CLASS __libc_lock_t NAME;
  93 # else
  94 #  define __libc_lock_define_initialized(CLASS,NAME) \
  95   CLASS __libc_lock_t NAME = LLL_LOCK_INITIALIZER;
  96 # endif
  97 #else
  98 # if __LT_SPINLOCK_INIT == 0
  99 #  define __libc_lock_define_initialized(CLASS,NAME) \
 100   CLASS __libc_lock_t NAME;
 101 # else
 102 #  define __libc_lock_define_initialized(CLASS,NAME) \
 103   CLASS __libc_lock_t NAME = PTHREAD_MUTEX_INITIALIZER;
 104 # endif
 105 #endif
 106
 107 #define __libc_rwlock_define_initialized(CLASS,NAME) \
 108   CLASS __libc_rwlock_t NAME = PTHREAD_RWLOCK_INITIALIZER;
 109
 110 /* Define an initialized recursive lock variable NAME with storage
 111    class CLASS.  */
 112 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 113 # if LLL_LOCK_INITIALIZER == 0
 114 #  define __libc_lock_define_initialized_recursive(CLASS,NAME) \
 115   CLASS __libc_lock_recursive_t NAME;
 116 # else
 117 #  define __libc_lock_define_initialized_recursive(CLASS,NAME) \
 118   CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;
 119 # endif
 120 # define _LIBC_LOCK_RECURSIVE_INITIALIZER \
 121   { LLL_LOCK_INITIALIZER, 0, NULL }
 122 #else
 123 # define __libc_lock_define_initialized_recursive(CLASS,NAME) \
 124   CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;
 125 # define _LIBC_LOCK_RECURSIVE_INITIALIZER \
 126   {PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP}
 127 #endif
 128
 129 #define __rtld_lock_define_initialized_recursive(CLASS,NAME) \
 130   CLASS __rtld_lock_recursive_t NAME = _RTLD_LOCK_RECURSIVE_INITIALIZER;
 131 #define _RTLD_LOCK_RECURSIVE_INITIALIZER \
 132   {PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP}
 133
 134 #define __rtld_lock_initialize(NAME) \
 135   (void) ((NAME) = (__rtld_lock_recursive_t) _RTLD_LOCK_RECURSIVE_INITIALIZER)
 136
 137 /* If we check for a weakly referenced symbol and then perform a
 138    normal jump to it te code generated for some platforms in case of
 139    PIC is unnecessarily slow.  What would happen is that the function
 140    is first referenced as data and then it is called indirectly
 141    through the PLT.  We can make this a direct jump.  */
 142 #ifdef __PIC__
 143 # define __libc_maybe_call(FUNC, ARGS, ELSE) \
 144   (__extension__ ({ __typeof (FUNC) *_fn = (FUNC); \
 145                     _fn != NULL ? (*_fn) ARGS : ELSE; }))
 146 #else
 147 # define __libc_maybe_call(FUNC, ARGS, ELSE) \
 148   (FUNC != NULL ? FUNC ARGS : ELSE)
 149 #endif
 150
 151 /* Call thread functions through the function pointer table.  */
 152 #if defined SHARED && !defined NOT_IN_libc
 153 # define PTFAVAIL(NAME) __libc_pthread_functions_init
 154 # define __libc_ptf_call(FUNC, ARGS, ELSE) \
 155   (__libc_pthread_functions_init ? PTHFCT_CALL (ptr_##FUNC, ARGS) : ELSE)
 156 # define __libc_ptf_call_always(FUNC, ARGS) \
 157   PTHFCT_CALL (ptr_##FUNC, ARGS)
 158 #else
 159 # define PTFAVAIL(NAME) (NAME != NULL)
 160 # define __libc_ptf_call(FUNC, ARGS, ELSE) \
 161   __libc_maybe_call (FUNC, ARGS, ELSE)
 162 # define __libc_ptf_call_always(FUNC, ARGS) \
 163   FUNC ARGS
 164 #endif
 165
 166
 167 /* Initialize the named lock variable, leaving it in a consistent, unlocked
 168    state.  */
 169 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 170 # define __libc_lock_init(NAME) ((NAME) = LLL_LOCK_INITIALIZER, 0)
 171 #else
 172 # define __libc_lock_init(NAME) \
 173   __libc_maybe_call (__pthread_mutex_init, (&(NAME), NULL), 0)
 174 #endif
 175 #define __libc_rwlock_init(NAME) \
 176   __libc_maybe_call (__pthread_rwlock_init, (&(NAME), NULL), 0)
 177
 178 /* Same as last but this time we initialize a recursive mutex.  */
 179 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 180 # define __libc_lock_init_recursive(NAME) \
 181   ((NAME) = (__libc_lock_recursive_t) _LIBC_LOCK_RECURSIVE_INITIALIZER, 0)
 182 #else
 183 # define __libc_lock_init_recursive(NAME) \
 184   do {                                                                        \
 185     if (__pthread_mutex_init != NULL)                                         \
 186       {                                                                       \
 187         pthread_mutexattr_t __attr;                                           \
 188         __pthread_mutexattr_init (&__attr);                                   \
 189         __pthread_mutexattr_settype (&__attr, PTHREAD_MUTEX_RECURSIVE_NP);    \
 190         __pthread_mutex_init (&(NAME).mutex, &__attr);                        \
 191         __pthread_mutexattr_destroy (&__attr);                                \
 192       }                                                                       \
 193   } while (0)
 194 #endif
 195
 196 #define __rtld_lock_init_recursive(NAME) \
 197   do {                                                                        \
 198     if (__pthread_mutex_init != NULL)                                         \
 199       {                                                                       \
 200         pthread_mutexattr_t __attr;                                           \
 201         __pthread_mutexattr_init (&__attr);                                   \
 202         __pthread_mutexattr_settype (&__attr, PTHREAD_MUTEX_RECURSIVE_NP);    \
 203         __pthread_mutex_init (&(NAME).mutex, &__attr);                        \
 204         __pthread_mutexattr_destroy (&__attr);                                \
 205       }                                                                       \
 206   } while (0)
 207
 208 /* Finalize the named lock variable, which must be locked.  It cannot be
 209    used again until __libc_lock_init is called again on it.  This must be
 210    called on a lock variable before the containing storage is reused.  */
 211 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 212 # define __libc_lock_fini(NAME) ((void) 0)
 213 #else
 214 # define __libc_lock_fini(NAME) \
 215   __libc_maybe_call (__pthread_mutex_destroy, (&(NAME)), 0)
 216 #endif
 217 #define __libc_rwlock_fini(NAME) \
 218   __libc_maybe_call (__pthread_rwlock_destroy, (&(NAME)), 0)
 219
 220 /* Finalize recursive named lock.  */
 221 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 222 # define __libc_lock_fini_recursive(NAME) ((void) 0)
 223 #else
 224 # define __libc_lock_fini_recursive(NAME) \
 225   __libc_maybe_call (__pthread_mutex_destroy, (&(NAME)), 0)
 226 #endif
 227
 228 /* Lock the named lock variable.  */
 229 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 230 # define __libc_lock_lock(NAME) \
 231   ({ lll_lock (NAME); 0; })
 232 #else
 233 # define __libc_lock_lock(NAME) \
 234   __libc_maybe_call (__pthread_mutex_lock, (&(NAME)), 0)
 235 #endif
 236 #define __libc_rwlock_rdlock(NAME) \
 237   __libc_ptf_call (__pthread_rwlock_rdlock, (&(NAME)), 0)
 238 #define __libc_rwlock_wrlock(NAME) \
 239   __libc_ptf_call (__pthread_rwlock_wrlock, (&(NAME)), 0)
 240
 241 /* Lock the recursive named lock variable.  */
 242 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 243 # define __libc_lock_lock_recursive(NAME) \
 244   do {                                                                        \
 245     void *self = THREAD_SELF;                                                 \
 246     if ((NAME).owner != self)                                                 \
 247       {                                                                       \
 248         lll_lock ((NAME).lock);                                               \
 249         (NAME).owner = self;                                                  \
 250       }                                                                       \
 251     ++(NAME).cnt;                                                             \
 252   } while (0)
 253 #else
 254 # define __libc_lock_lock_recursive(NAME) \
 255   __libc_maybe_call (__pthread_mutex_lock, (&(NAME).mutex), 0)
 256 #endif
 257
 258 /* Try to lock the named lock variable.  */
 259 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 260 # define __libc_lock_trylock(NAME) \
 261   lll_trylock (NAME)
 262 #else
 263 # define __libc_lock_trylock(NAME) \
 264   __libc_maybe_call (__pthread_mutex_trylock, (&(NAME)), 0)
 265 #endif
 266 #define __libc_rwlock_tryrdlock(NAME) \
 267   __libc_maybe_call (__pthread_rwlock_tryrdlock, (&(NAME)), 0)
 268 #define __libc_rwlock_trywrlock(NAME) \
 269   __libc_maybe_call (__pthread_rwlock_trywrlock, (&(NAME)), 0)
 270
 271 /* Try to lock the recursive named lock variable.  */
 272 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 273 # define __libc_lock_trylock_recursive(NAME) \
 274   ({                                                                          \
 275     int result = 0;                                                           \
 276     void *self = THREAD_SELF;                                                 \
 277     if ((NAME).owner != self)                                                 \
 278       {                                                                       \
 279         if (lll_trylock ((NAME).lock) == 0)                                   \
 280           {                                                                   \
 281             (NAME).owner = self;                                              \
 282             (NAME).cnt = 1;                                                   \
 283           }                                                                   \
 284         else                                                                  \
 285           result = EBUSY;                                                     \
 286       }                                                                       \
 287     else                                                                      \
 288       ++(NAME).cnt;                                                           \
 289     result;                                                                   \
 290   })
 291 #else
 292 # define __libc_lock_trylock_recursive(NAME) \
 293   __libc_maybe_call (__pthread_mutex_trylock, (&(NAME)), 0)
 294 #endif
 295
 296 #define __rtld_lock_trylock_recursive(NAME) \
 297   __libc_maybe_call (__pthread_mutex_trylock, (&(NAME).mutex), 0)
 298
 299 /* Unlock the named lock variable.  */
 300 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 301 # define __libc_lock_unlock(NAME) \
 302   lll_unlock (NAME)
 303 #else
 304 # define __libc_lock_unlock(NAME) \
 305   __libc_maybe_call (__pthread_mutex_unlock, (&(NAME)), 0)
 306 #endif
 307 #define __libc_rwlock_unlock(NAME) \
 308   __libc_ptf_call (__pthread_rwlock_unlock, (&(NAME)), 0)
 309
 310 /* Unlock the recursive named lock variable.  */
 311 #if defined _LIBC && (!defined NOT_IN_libc || defined IS_IN_libpthread)
 312 /* We do no error checking here.  */
 313 # define __libc_lock_unlock_recursive(NAME) \
 314   do {                                                                        \
 315     if (--(NAME).cnt == 0)                                                    \
 316       {                                                                       \
 317         (NAME).owner = NULL;                                                  \
 318         lll_unlock ((NAME).lock);                                             \
 319       }                                                                       \
 320   } while (0)
 321 #else
 322 # define __libc_lock_unlock_recursive(NAME) \
 323   __libc_maybe_call (__pthread_mutex_unlock, (&(NAME)), 0)
 324 #endif
 325
 326 #if defined _LIBC && defined SHARED
 327 # define __rtld_lock_default_lock_recursive(lock) \
 328   ++((pthread_mutex_t *)(lock))->__data.__count;
 329
 330 # define __rtld_lock_default_unlock_recursive(lock) \
 331   --((pthread_mutex_t *)(lock))->__data.__count;
 332
 333 # define __rtld_lock_lock_recursive(NAME) \
 334   GL(dl_rtld_lock_recursive) (&(NAME).mutex)
 335
 336 # define __rtld_lock_unlock_recursive(NAME) \
 337   GL(dl_rtld_unlock_recursive) (&(NAME).mutex)
 338 #else
 339 # define __rtld_lock_lock_recursive(NAME) \
 340   __libc_maybe_call (__pthread_mutex_lock, (&(NAME).mutex), 0)
 341
 342 # define __rtld_lock_unlock_recursive(NAME) \
 343   __libc_maybe_call (__pthread_mutex_unlock, (&(NAME).mutex), 0)
 344 #endif
 345
 346 /* Define once control variable.  */
 347 #if PTHREAD_ONCE_INIT == 0
 348 /* Special case for static variables where we can avoid the initialization
 349    if it is zero.  */
 350 # define __libc_once_define(CLASS, NAME) \
 351   CLASS pthread_once_t NAME
 352 #else
 353 # define __libc_once_define(CLASS, NAME) \
 354   CLASS pthread_once_t NAME = PTHREAD_ONCE_INIT
 355 #endif
 356
 357 /* Call handler iff the first call.  */
 358 #define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
 359   do {                                                                        \
 360     if (PTFAVAIL (__pthread_once))                                            \
 361       __libc_ptf_call_always (__pthread_once, (&(ONCE_CONTROL),               \
 362                                                INIT_FUNCTION));               \
 363     else if ((ONCE_CONTROL) == PTHREAD_ONCE_INIT) {                           \
 364       INIT_FUNCTION ();                                                       \
 365       (ONCE_CONTROL) |= 2;                                                    \
 366     }                                                                         \
 367   } while (0)
 368
 369
 370 /* Note that for I/O cleanup handling we are using the old-style
 371    cancel handling.  It does not have to be integrated with C++ snce
 372    no C++ code is called in the middle.  The old-style handling is
 373    faster and the support is not going away.  */
 374 extern void _pthread_cleanup_push (struct _pthread_cleanup_buffer *buffer,
 375                                    void (*routine) (void *), void *arg);
 376 extern void _pthread_cleanup_pop (struct _pthread_cleanup_buffer *buffer,
 377                                   int execute);
 378 extern void _pthread_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer,
 379                                          void (*routine) (void *), void *arg);
 380 extern void _pthread_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer,
 381                                           int execute);
 382
 383 /* Start critical region with cleanup.  */
 384 #define __libc_cleanup_region_start(DOIT, FCT, ARG) \
 385   { struct _pthread_cleanup_buffer _buffer;                                   \
 386     int _avail;                                                               \
 387     if (DOIT) {                                                               \
 388       _avail = PTFAVAIL (_pthread_cleanup_push_defer);                        \
 389       if (_avail) {                                                           \
 390         __libc_ptf_call_always (_pthread_cleanup_push_defer, (&_buffer, FCT,  \
 391                                                               ARG));          \
 392       } else {                                                                \
 393         _buffer.__routine = (FCT);                                            \
 394         _buffer.__arg = (ARG);                                                \
 395       }                                                                       \
 396     } else {                                                                  \
 397       _avail = 0;                                                             \
 398     }
 399
 400 /* End critical region with cleanup.  */
 401 #define __libc_cleanup_region_end(DOIT) \
 402     if (_avail) {                                                             \
 403       __libc_ptf_call_always (_pthread_cleanup_pop_restore, (&_buffer, DOIT));\
 404     } else if (DOIT)                                                          \
 405       _buffer.__routine (_buffer.__arg);                                      \
 406   }
 407
 408 /* Sometimes we have to exit the block in the middle.  */
 409 #define __libc_cleanup_end(DOIT) \
 410     if (_avail) {                                                             \
 411       __libc_ptf_call_always (_pthread_cleanup_pop_restore, (&_buffer, DOIT));\
 412     } else if (DOIT)                                                          \
 413       _buffer.__routine (_buffer.__arg)
 414
 415
 416 /* Normal cleanup handling, based on C cleanup attribute.  */
 417 __extern_inline void
 418 __libc_cleanup_routine (struct __pthread_cleanup_frame *f)
 419 {
 420   if (f->__do_it)
 421     f->__cancel_routine (f->__cancel_arg);
 422 }
 423
 424 #define __libc_cleanup_push(fct, arg) \
 425   do {                                                                        \
 426     struct __pthread_cleanup_frame __clframe                                  \
 427       __attribute__ ((__cleanup__ (__libc_cleanup_routine)))                  \
 428       = { .__cancel_routine = (fct), .__cancel_arg = (arg),                   \
 429           .__do_it = 1 };
 430
 431 #define __libc_cleanup_pop(execute) \
 432     __clframe.__do_it = (execute);                                            \
 433   } while (0)
 434
 435
 436 /* Create thread-specific key.  */
 437 #define __libc_key_create(KEY, DESTRUCTOR) \
 438   __libc_ptf_call (__pthread_key_create, (KEY, DESTRUCTOR), 1)
 439
 440 /* Get thread-specific data.  */
 441 #define __libc_getspecific(KEY) \
 442   __libc_ptf_call (__pthread_getspecific, (KEY), NULL)
 443
 444 /* Set thread-specific data.  */
 445 #define __libc_setspecific(KEY, VALUE) \
 446   __libc_ptf_call (__pthread_setspecific, (KEY, VALUE), 0)
 447
 448
 449 /* Register handlers to execute before and after `fork'.  Note that the
 450    last parameter is NULL.  The handlers registered by the libc are
 451    never removed so this is OK.  */
 452 #define __libc_atfork(PREPARE, PARENT, CHILD) \
 453   __register_atfork (PREPARE, PARENT, CHILD, NULL)
 454 extern int __register_atfork (void (*__prepare) (void),
 455                               void (*__parent) (void),
 456                               void (*__child) (void),
 457                               void *__dso_handle);
 458
 459 /* Functions that are used by this file and are internal to the GNU C
 460    library.  */
 461
 462 extern int __pthread_mutex_init (pthread_mutex_t *__mutex,
 463                                  __const pthread_mutexattr_t *__mutex_attr);
 464
 465 extern int __pthread_mutex_destroy (pthread_mutex_t *__mutex);
 466
 467 extern int __pthread_mutex_trylock (pthread_mutex_t *__mutex);
 468
 469 extern int __pthread_mutex_lock (pthread_mutex_t *__mutex);
 470
 471 extern int __pthread_mutex_unlock (pthread_mutex_t *__mutex);
 472
 473 extern int __pthread_mutexattr_init (pthread_mutexattr_t *__attr);
 474
 475 extern int __pthread_mutexattr_destroy (pthread_mutexattr_t *__attr);
 476
 477 extern int __pthread_mutexattr_settype (pthread_mutexattr_t *__attr,
 478                                         int __kind);
 479
 480 #ifdef __USE_UNIX98
 481 extern int __pthread_rwlock_init (pthread_rwlock_t *__rwlock,
 482                                   __const pthread_rwlockattr_t *__attr);
 483
 484 extern int __pthread_rwlock_destroy (pthread_rwlock_t *__rwlock);
 485
 486 extern int __pthread_rwlock_rdlock (pthread_rwlock_t *__rwlock);
 487
 488 extern int __pthread_rwlock_tryrdlock (pthread_rwlock_t *__rwlock);
 489
 490 extern int __pthread_rwlock_wrlock (pthread_rwlock_t *__rwlock);
 491
 492 extern int __pthread_rwlock_trywrlock (pthread_rwlock_t *__rwlock);
 493
 494 extern int __pthread_rwlock_unlock (pthread_rwlock_t *__rwlock);
 495 #endif
 496
 497 extern int __pthread_key_create (pthread_key_t *__key,
 498                                  void (*__destr_function) (void *));
 499
 500 extern int __pthread_setspecific (pthread_key_t __key,
 501                                   __const void *__pointer);
 502
 503 extern void *__pthread_getspecific (pthread_key_t __key);
 504
 505 extern int __pthread_once (pthread_once_t *__once_control,
 506                            void (*__init_routine) (void));
 507
 508 extern int __pthread_atfork (void (*__prepare) (void),
 509                              void (*__parent) (void),
 510                              void (*__child) (void));
 511
 512
 513
 514 /* Make the pthread functions weak so that we can elide them from
 515    single-threaded processes.  */
 516 #ifndef __NO_WEAK_PTHREAD_ALIASES
 517 # ifdef weak_extern
 518 #  if _LIBC
 519 #   include <bp-sym.h>
 520 #  else
 521 #   define BP_SYM (sym) sym
 522 #  endif
 523 weak_extern (BP_SYM (__pthread_mutex_init))
 524 weak_extern (BP_SYM (__pthread_mutex_destroy))
 525 weak_extern (BP_SYM (__pthread_mutex_lock))
 526 weak_extern (BP_SYM (__pthread_mutex_trylock))
 527 weak_extern (BP_SYM (__pthread_mutex_unlock))
 528 weak_extern (BP_SYM (__pthread_mutexattr_init))
 529 weak_extern (BP_SYM (__pthread_mutexattr_destroy))
 530 weak_extern (BP_SYM (__pthread_mutexattr_settype))
 531 weak_extern (BP_SYM (__pthread_rwlock_init))
 532 weak_extern (BP_SYM (__pthread_rwlock_destroy))
 533 weak_extern (BP_SYM (__pthread_rwlock_rdlock))
 534 weak_extern (BP_SYM (__pthread_rwlock_tryrdlock))
 535 weak_extern (BP_SYM (__pthread_rwlock_wrlock))
 536 weak_extern (BP_SYM (__pthread_rwlock_trywrlock))
 537 weak_extern (BP_SYM (__pthread_rwlock_unlock))
 538 weak_extern (BP_SYM (__pthread_key_create))
 539 weak_extern (BP_SYM (__pthread_setspecific))
 540 weak_extern (BP_SYM (__pthread_getspecific))
 541 weak_extern (BP_SYM (__pthread_once))
 542 weak_extern (__pthread_initialize)
 543 weak_extern (__pthread_atfork)
 544 weak_extern (BP_SYM (_pthread_cleanup_push_defer))
 545 weak_extern (BP_SYM (_pthread_cleanup_pop_restore))
 546 weak_extern (BP_SYM (pthread_setcancelstate))
 547 # else
 548 #  pragma weak __pthread_mutex_init
 549 #  pragma weak __pthread_mutex_destroy
 550 #  pragma weak __pthread_mutex_lock
 551 #  pragma weak __pthread_mutex_trylock
 552 #  pragma weak __pthread_mutex_unlock
 553 #  pragma weak __pthread_mutexattr_init
 554 #  pragma weak __pthread_mutexattr_destroy
 555 #  pragma weak __pthread_mutexattr_settype
 556 #  pragma weak __pthread_rwlock_destroy
 557 #  pragma weak __pthread_rwlock_rdlock
 558 #  pragma weak __pthread_rwlock_tryrdlock
 559 #  pragma weak __pthread_rwlock_wrlock
 560 #  pragma weak __pthread_rwlock_trywrlock
 561 #  pragma weak __pthread_rwlock_unlock
 562 #  pragma weak __pthread_key_create
 563 #  pragma weak __pthread_setspecific
 564 #  pragma weak __pthread_getspecific
 565 #  pragma weak __pthread_once
 566 #  pragma weak __pthread_initialize
 567 #  pragma weak __pthread_atfork
 568 #  pragma weak _pthread_cleanup_push_defer
 569 #  pragma weak _pthread_cleanup_pop_restore
 570 #  pragma weak pthread_setcancelstate
 571 # endif
 572 #endif
 573
 574 #endif  /* bits/libc-lock.h */