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

   1 /* libc-internal interface for mutex locks.  LinuxThreads version.
   2    Copyright (C) 1996,1997,1998,1999,2000,2001,2002,2003
   3         Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public License as
   8    published by the Free Software Foundation; either version 2.1 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #ifndef _BITS_LIBC_LOCK_H
  22 #define _BITS_LIBC_LOCK_H 1
  23
  24 #include <pthread.h>
  25
  26 #if defined _LIBC && !defined NOT_IN_libc
  27 #include <linuxthreads/internals.h>
  28 #endif
  29
  30 /* Mutex type.  */
  31 #if defined(_LIBC) || defined(_IO_MTSAFE_IO)
  32 typedef pthread_mutex_t __libc_lock_t;
  33 typedef struct { pthread_mutex_t mutex; } __libc_lock_recursive_t;
  34 # ifdef __USE_UNIX98
  35 typedef pthread_rwlock_t __libc_rwlock_t;
  36 # else
  37 typedef struct __libc_rwlock_opaque__ __libc_rwlock_t;
  38 # endif
  39 typedef __libc_lock_recursive_t __rtld_lock_recursive_t;
  40 #else
  41 typedef struct __libc_lock_opaque__ __libc_lock_t;
  42 typedef struct __libc_lock_recursive_opaque__ __libc_lock_recursive_t;
  43 typedef struct __libc_rwlock_opaque__ __libc_rwlock_t;
  44 #endif
  45
  46 /* Type for key to thread-specific data.  */
  47 typedef pthread_key_t __libc_key_t;
  48
  49 /* Define a lock variable NAME with storage class CLASS.  The lock must be
  50    initialized with __libc_lock_init before it can be used (or define it
  51    with __libc_lock_define_initialized, below).  Use `extern' for CLASS to
  52    declare a lock defined in another module.  In public structure
  53    definitions you must use a pointer to the lock structure (i.e., NAME
  54    begins with a `*'), because its storage size will not be known outside
  55    of libc.  */
  56 #define __libc_lock_define(CLASS,NAME) \
  57   CLASS __libc_lock_t NAME;
  58 #define __libc_rwlock_define(CLASS,NAME) \
  59   CLASS __libc_rwlock_t NAME;
  60 #define __libc_lock_define_recursive(CLASS,NAME) \
  61   CLASS __libc_lock_recursive_t NAME;
  62 #define __rtld_lock_define_recursive(CLASS,NAME) \
  63   CLASS __rtld_lock_recursive_t NAME;
  64
  65 /* Define an initialized lock variable NAME with storage class CLASS.
  66
  67    For the C library we take a deeper look at the initializer.  For
  68    this implementation all fields are initialized to zero.  Therefore
  69    we don't initialize the variable which allows putting it into the
  70    BSS section.  (Except on PA-RISC and other odd architectures, where
  71    initialized locks must be set to one due to the lack of normal
  72    atomic operations.) */
  73
  74 #if __LT_SPINLOCK_INIT == 0
  75 #  define __libc_lock_define_initialized(CLASS,NAME) \
  76   CLASS __libc_lock_t NAME;
  77 #else
  78 #  define __libc_lock_define_initialized(CLASS,NAME) \
  79   CLASS __libc_lock_t NAME = PTHREAD_MUTEX_INITIALIZER;
  80 #endif
  81
  82 #define __libc_rwlock_define_initialized(CLASS,NAME) \
  83   CLASS __libc_rwlock_t NAME = PTHREAD_RWLOCK_INITIALIZER;
  84
  85 /* Define an initialized recursive lock variable NAME with storage
  86    class CLASS.  */
  87 #define __libc_lock_define_initialized_recursive(CLASS,NAME) \
  88   CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;
  89 #define _LIBC_LOCK_RECURSIVE_INITIALIZER \
  90   {PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP}
  91
  92 #define __rtld_lock_define_initialized_recursive(CLASS,NAME) \
  93   CLASS __rtld_lock_recursive_t NAME = _RTLD_LOCK_RECURSIVE_INITIALIZER;
  94 #define _RTLD_LOCK_RECURSIVE_INITIALIZER \
  95   {PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP}
  96
  97 #if defined _LIBC && defined IS_IN_libpthread
  98 # define __libc_maybe_call(FUNC, ARGS, ELSE) FUNC ARGS
  99 #else
 100 # if defined __PIC__ || (defined _LIBC && defined SHARED)
 101 #  define __libc_maybe_call(FUNC, ARGS, ELSE) \
 102   (__extension__ ({ __typeof (FUNC) *_fn = (FUNC); \
 103                     _fn != NULL ? (*_fn) ARGS : ELSE; }))
 104 # else
 105 #  define __libc_maybe_call(FUNC, ARGS, ELSE) \
 106   (FUNC != NULL ? FUNC ARGS : ELSE)
 107 # endif
 108 #endif
 109 #if defined _LIBC && !defined NOT_IN_libc && defined SHARED
 110 # define __libc_maybe_call2(FUNC, ARGS, ELSE) \
 111   ({__builtin_expect (__libc_pthread_functions.ptr_##FUNC != NULL, 0) \
 112     ? __libc_pthread_functions.ptr_##FUNC ARGS : ELSE; })
 113 #else
 114 # define __libc_maybe_call2(FUNC, ARGS, ELSE) __libc_maybe_call (__##FUNC, ARGS, ELSE)
 115 #endif
 116
 117 /* Initialize the named lock variable, leaving it in a consistent, unlocked
 118    state.  */
 119 #if defined _LIBC && !defined NOT_IN_libc && defined SHARED
 120 #define __libc_lock_init(NAME) \
 121   ({                                                                          \
 122     (NAME).__m_count = 0;                                                     \
 123     (NAME).__m_owner = NULL;                                                  \
 124     (NAME).__m_kind = PTHREAD_MUTEX_TIMED_NP;                                 \
 125     (NAME).__m_lock.__status = 0;                                             \
 126     (NAME).__m_lock.__spinlock = __LT_SPINLOCK_INIT;                          \
 127     0; })
 128 #else
 129 #define __libc_lock_init(NAME) \
 130   (__libc_maybe_call2 (pthread_mutex_init, (&(NAME), NULL), 0))
 131 #endif
 132 #define __libc_rwlock_init(NAME) \
 133   (__libc_maybe_call (__pthread_rwlock_init, (&(NAME), NULL), 0));
 134
 135 /* Same as last but this time we initialize a recursive mutex.  */
 136 #if defined _LIBC && !defined NOT_IN_libc && defined SHARED
 137 #define __libc_lock_init_recursive(NAME) \
 138   ({                                                                          \
 139     (NAME).mutex.__m_count = 0;                                               \
 140     (NAME).mutex.__m_owner = NULL;                                            \
 141     (NAME).mutex.__m_kind = PTHREAD_MUTEX_RECURSIVE_NP;                       \
 142     (NAME).mutex.__m_lock.__status = 0;                                       \
 143     (NAME).mutex.__m_lock.__spinlock = __LT_SPINLOCK_INIT;                    \
 144     0; })
 145 #else
 146 #define __libc_lock_init_recursive(NAME) \
 147   do {                                                                        \
 148     if (__pthread_mutex_init != NULL)                                         \
 149       {                                                                       \
 150         pthread_mutexattr_t __attr;                                           \
 151         __pthread_mutexattr_init (&__attr);                                   \
 152         __pthread_mutexattr_settype (&__attr, PTHREAD_MUTEX_RECURSIVE_NP); \
 153         __pthread_mutex_init (&(NAME).mutex, &__attr);                        \
 154         __pthread_mutexattr_destroy (&__attr);                                \
 155       }                                                                       \
 156   } while (0);
 157 #endif
 158 #define __rtld_lock_init_recursive(NAME) \
 159   __libc_lock_init_recursive (NAME)
 160
 161 /* Finalize the named lock variable, which must be locked.  It cannot be
 162    used again until __libc_lock_init is called again on it.  This must be
 163    called on a lock variable before the containing storage is reused.  */
 164 #define __libc_lock_fini(NAME) \
 165   (__libc_maybe_call2 (pthread_mutex_destroy, (&(NAME)), 0));
 166 #define __libc_rwlock_fini(NAME) \
 167   (__libc_maybe_call (__pthread_rwlock_destroy, (&(NAME)), 0));
 168
 169 /* Finalize recursive named lock.  */
 170 #define __libc_lock_fini_recursive(NAME) __libc_lock_fini ((NAME).mutex)
 171 #define __rtld_lock_fini_recursive(NAME) __libc_lock_fini_recursive (NAME)
 172
 173 /* Lock the named lock variable.  */
 174 #define __libc_lock_lock(NAME) \
 175   (__libc_maybe_call2 (pthread_mutex_lock, (&(NAME)), 0));
 176 #define __libc_rwlock_rdlock(NAME) \
 177   (__libc_maybe_call (__pthread_rwlock_rdlock, (&(NAME)), 0));
 178 #define __libc_rwlock_wrlock(NAME) \
 179   (__libc_maybe_call (__pthread_rwlock_wrlock, (&(NAME)), 0));
 180
 181 /* Lock the recursive named lock variable.  */
 182 #define __libc_lock_lock_recursive(NAME) __libc_lock_lock ((NAME).mutex)
 183
 184 /* Try to lock the named lock variable.  */
 185 #define __libc_lock_trylock(NAME) \
 186   (__libc_maybe_call2 (pthread_mutex_trylock, (&(NAME)), 0))
 187 #define __libc_rwlock_tryrdlock(NAME) \
 188   (__libc_maybe_call (__pthread_rwlock_tryrdlock, (&(NAME)), 0))
 189 #define __libc_rwlock_trywrlock(NAME) \
 190   (__libc_maybe_call (__pthread_rwlock_trywrlock, (&(NAME)), 0))
 191
 192 /* Try to lock the recursive named lock variable.  */
 193 #define __libc_lock_trylock_recursive(NAME) __libc_lock_trylock ((NAME).mutex)
 194 #define __rtld_lock_trylock_recursive(NAME) \
 195   __libc_lock_trylock_recursive (NAME)
 196
 197 /* Unlock the named lock variable.  */
 198 #define __libc_lock_unlock(NAME) \
 199   (__libc_maybe_call2 (pthread_mutex_unlock, (&(NAME)), 0));
 200 #define __libc_rwlock_unlock(NAME) \
 201   (__libc_maybe_call (__pthread_rwlock_unlock, (&(NAME)), 0));
 202
 203 /* Unlock the recursive named lock variable.  */
 204 #define __libc_lock_unlock_recursive(NAME) __libc_lock_unlock ((NAME).mutex)
 205
 206 #if defined _LIBC && defined SHARED
 207 # define __rtld_lock_default_lock_recursive(lock) \
 208   ++((pthread_mutex_t *)(lock))->__m_count;
 209
 210 # define __rtld_lock_default_unlock_recursive(lock) \
 211   --((pthread_mutex_t *)(lock))->__m_count;
 212
 213 # define __rtld_lock_lock_recursive(NAME) \
 214   GL(dl_rtld_lock_recursive) (&(NAME).mutex)
 215
 216 # define __rtld_lock_unlock_recursive(NAME) \
 217   GL(dl_rtld_unlock_recursive) (&(NAME).mutex)
 218 #else
 219 #define __rtld_lock_lock_recursive(NAME) __libc_lock_lock_recursive (NAME)
 220 #define __rtld_lock_unlock_recursive(NAME) __libc_lock_unlock_recursive (NAME)
 221 #endif
 222
 223 /* Define once control variable.  */
 224 #if PTHREAD_ONCE_INIT == 0
 225 /* Special case for static variables where we can avoid the initialization
 226    if it is zero.  */
 227 # define __libc_once_define(CLASS, NAME) \
 228   CLASS pthread_once_t NAME
 229 #else
 230 # define __libc_once_define(CLASS, NAME) \
 231   CLASS pthread_once_t NAME = PTHREAD_ONCE_INIT
 232 #endif
 233
 234 /* Call handler iff the first call.  */
 235 #define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
 236   do {                                                                        \
 237     if (__pthread_once != NULL)                                               \
 238       __pthread_once (&(ONCE_CONTROL), (INIT_FUNCTION));                      \
 239     else if ((ONCE_CONTROL) == PTHREAD_ONCE_INIT) {                           \
 240       INIT_FUNCTION ();                                                       \
 241       (ONCE_CONTROL) = 2;                                                     \
 242     }                                                                         \
 243   } while (0)
 244
 245
 246 /* Start critical region with cleanup.  */
 247 #define __libc_cleanup_region_start(DOIT, FCT, ARG) \
 248   { struct _pthread_cleanup_buffer _buffer;                                   \
 249     int _avail = (DOIT) && _pthread_cleanup_push_defer != NULL;               \
 250     if (_avail) {                                                             \
 251       _pthread_cleanup_push_defer (&_buffer, (FCT), (ARG));                   \
 252     }
 253
 254 /* End critical region with cleanup.  */
 255 #define __libc_cleanup_region_end(DOIT) \
 256     if (_avail) {                                                             \
 257       _pthread_cleanup_pop_restore (&_buffer, (DOIT));                        \
 258     }                                                                         \
 259   }
 260
 261 /* Sometimes we have to exit the block in the middle.  */
 262 #define __libc_cleanup_end(DOIT) \
 263     if (_avail) {                                                             \
 264       _pthread_cleanup_pop_restore (&_buffer, (DOIT));                        \
 265     }
 266
 267 #define __libc_cleanup_push(fct, arg) \
 268     { struct _pthread_cleanup_buffer _buffer;                                 \
 269     __libc_maybe_call (_pthread_cleanup_push, (&_buffer, (fct), (arg)), 0)
 270
 271 #define __libc_cleanup_pop(execute) \
 272     __libc_maybe_call (_pthread_cleanup_pop, (&_buffer, execute), 0);         \
 273     }
 274
 275 /* Create thread-specific key.  */
 276 #define __libc_key_create(KEY, DESTRUCTOR) \
 277   (__libc_maybe_call (__pthread_key_create, (KEY, DESTRUCTOR), 1))
 278
 279 /* Get thread-specific data.  */
 280 #define __libc_getspecific(KEY) \
 281   (__libc_maybe_call (__pthread_getspecific, (KEY), NULL))
 282
 283 /* Set thread-specific data.  */
 284 #define __libc_setspecific(KEY, VALUE) \
 285   (__libc_maybe_call (__pthread_setspecific, (KEY, VALUE), 0))
 286
 287
 288 /* Register handlers to execute before and after `fork'.  */
 289 #define __libc_atfork(PREPARE, PARENT, CHILD) \
 290   (__libc_maybe_call (__pthread_atfork, (PREPARE, PARENT, CHILD), 0))
 291
 292 /* Functions that are used by this file and are internal to the GNU C
 293    library.  */
 294
 295 extern int __pthread_mutex_init (pthread_mutex_t *__mutex,
 296                                  __const pthread_mutexattr_t *__mutex_attr);
 297
 298 extern int __pthread_mutex_destroy (pthread_mutex_t *__mutex);
 299
 300 extern int __pthread_mutex_trylock (pthread_mutex_t *__mutex);
 301
 302 extern int __pthread_mutex_lock (pthread_mutex_t *__mutex);
 303
 304 extern int __pthread_mutex_unlock (pthread_mutex_t *__mutex);
 305
 306 extern int __pthread_mutexattr_init (pthread_mutexattr_t *__attr);
 307
 308 extern int __pthread_mutexattr_destroy (pthread_mutexattr_t *__attr);
 309
 310 extern int __pthread_mutexattr_settype (pthread_mutexattr_t *__attr,
 311                                         int __kind);
 312
 313 #ifdef __USE_UNIX98
 314 extern int __pthread_rwlock_init (pthread_rwlock_t *__rwlock,
 315                                   __const pthread_rwlockattr_t *__attr);
 316
 317 extern int __pthread_rwlock_destroy (pthread_rwlock_t *__rwlock);
 318
 319 extern int __pthread_rwlock_rdlock (pthread_rwlock_t *__rwlock);
 320
 321 extern int __pthread_rwlock_tryrdlock (pthread_rwlock_t *__rwlock);
 322
 323 extern int __pthread_rwlock_wrlock (pthread_rwlock_t *__rwlock);
 324
 325 extern int __pthread_rwlock_trywrlock (pthread_rwlock_t *__rwlock);
 326
 327 extern int __pthread_rwlock_unlock (pthread_rwlock_t *__rwlock);
 328 #endif
 329
 330 extern int __pthread_key_create (pthread_key_t *__key,
 331                                  void (*__destr_function) (void *));
 332
 333 extern int __pthread_setspecific (pthread_key_t __key,
 334                                   __const void *__pointer);
 335
 336 extern void *__pthread_getspecific (pthread_key_t __key);
 337
 338 extern int __pthread_once (pthread_once_t *__once_control,
 339                            void (*__init_routine) (void));
 340
 341 extern int __pthread_atfork (void (*__prepare) (void),
 342                              void (*__parent) (void),
 343                              void (*__child) (void));
 344
 345
 346
 347 /* Make the pthread functions weak so that we can elide them from
 348    single-threaded processes.  */
 349 #ifndef __NO_WEAK_PTHREAD_ALIASES
 350 # ifdef weak_extern
 351 #  if _LIBC
 352 #   include <bp-sym.h>
 353 #  else
 354 #   define BP_SYM (sym) sym
 355 #  endif
 356 weak_extern (BP_SYM (__pthread_mutex_init))
 357 weak_extern (BP_SYM (__pthread_mutex_destroy))
 358 weak_extern (BP_SYM (__pthread_mutex_lock))
 359 weak_extern (BP_SYM (__pthread_mutex_trylock))
 360 weak_extern (BP_SYM (__pthread_mutex_unlock))
 361 weak_extern (BP_SYM (__pthread_mutexattr_init))
 362 weak_extern (BP_SYM (__pthread_mutexattr_destroy))
 363 weak_extern (BP_SYM (__pthread_mutexattr_settype))
 364 weak_extern (BP_SYM (__pthread_rwlock_init))
 365 weak_extern (BP_SYM (__pthread_rwlock_destroy))
 366 weak_extern (BP_SYM (__pthread_rwlock_rdlock))
 367 weak_extern (BP_SYM (__pthread_rwlock_tryrdlock))
 368 weak_extern (BP_SYM (__pthread_rwlock_wrlock))
 369 weak_extern (BP_SYM (__pthread_rwlock_trywrlock))
 370 weak_extern (BP_SYM (__pthread_rwlock_unlock))
 371 weak_extern (BP_SYM (__pthread_key_create))
 372 weak_extern (BP_SYM (__pthread_setspecific))
 373 weak_extern (BP_SYM (__pthread_getspecific))
 374 weak_extern (BP_SYM (__pthread_once))
 375 weak_extern (__pthread_initialize)
 376 weak_extern (__pthread_atfork)
 377 weak_extern (BP_SYM (_pthread_cleanup_push))
 378 weak_extern (BP_SYM (_pthread_cleanup_pop))
 379 weak_extern (BP_SYM (_pthread_cleanup_push_defer))
 380 weak_extern (BP_SYM (_pthread_cleanup_pop_restore))
 381 # else
 382 #  pragma weak __pthread_mutex_init
 383 #  pragma weak __pthread_mutex_destroy
 384 #  pragma weak __pthread_mutex_lock
 385 #  pragma weak __pthread_mutex_trylock
 386 #  pragma weak __pthread_mutex_unlock
 387 #  pragma weak __pthread_mutexattr_init
 388 #  pragma weak __pthread_mutexattr_destroy
 389 #  pragma weak __pthread_mutexattr_settype
 390 #  pragma weak __pthread_rwlock_destroy
 391 #  pragma weak __pthread_rwlock_rdlock
 392 #  pragma weak __pthread_rwlock_tryrdlock
 393 #  pragma weak __pthread_rwlock_wrlock
 394 #  pragma weak __pthread_rwlock_trywrlock
 395 #  pragma weak __pthread_rwlock_unlock
 396 #  pragma weak __pthread_key_create
 397 #  pragma weak __pthread_setspecific
 398 #  pragma weak __pthread_getspecific
 399 #  pragma weak __pthread_once
 400 #  pragma weak __pthread_initialize
 401 #  pragma weak __pthread_atfork
 402 #  pragma weak _pthread_cleanup_push_defer
 403 #  pragma weak _pthread_cleanup_pop_restore
 404 #  pragma weak _pthread_cleanup_push
 405 #  pragma weak _pthread_cleanup_pop
 406 # endif
 407 #endif
 408
 409 /* We need portable names for some functions.  E.g., when they are
 410    used as argument to __libc_cleanup_region_start.  */
 411 #define __libc_mutex_unlock __pthread_mutex_unlock
 412
 413 #endif  /* bits/libc-lock.h */