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

   1 /* libc-internal interface for mutex locks.  LinuxThreads version.
   2    Copyright (C) 1996,1997,1998,1999,2000,2001,2002,2003,2006
   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
  18    not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef _BITS_LIBC_LOCK_H
  21 #define _BITS_LIBC_LOCK_H 1
  22
  23 #include <pthread.h>
  24
  25 #if defined _LIBC && !defined NOT_IN_libc
  26 #include <linuxthreads/internals.h>
  27 #endif
  28
  29 /* Mutex type.  */
  30 #if defined(_LIBC) || defined(_IO_MTSAFE_IO)
  31 typedef pthread_mutex_t __libc_lock_t;
  32 typedef struct { pthread_mutex_t mutex; } __libc_lock_recursive_t;
  33 # ifdef __USE_UNIX98
  34 typedef pthread_rwlock_t __libc_rwlock_t;
  35 # else
  36 typedef struct __libc_rwlock_opaque__ __libc_rwlock_t;
  37 # endif
  38 typedef __libc_lock_recursive_t __rtld_lock_recursive_t;
  39 #else
  40 typedef struct __libc_lock_opaque__ __libc_lock_t;
  41 typedef struct __libc_lock_recursive_opaque__ __libc_lock_recursive_t;
  42 typedef struct __libc_rwlock_opaque__ __libc_rwlock_t;
  43 #endif
  44
  45 /* Type for key to thread-specific data.  */
  46 typedef pthread_key_t __libc_key_t;
  47
  48 /* Define a lock variable NAME with storage class CLASS.  The lock must be
  49    initialized with __libc_lock_init before it can be used (or define it
  50    with __libc_lock_define_initialized, below).  Use `extern' for CLASS to
  51    declare a lock defined in another module.  In public structure
  52    definitions you must use a pointer to the lock structure (i.e., NAME
  53    begins with a `*'), because its storage size will not be known outside
  54    of libc.  */
  55 #define __libc_lock_define(CLASS,NAME) \
  56   CLASS __libc_lock_t NAME;
  57 #define __libc_rwlock_define(CLASS,NAME) \
  58   CLASS __libc_rwlock_t NAME;
  59 #define __libc_lock_define_recursive(CLASS,NAME) \
  60   CLASS __libc_lock_recursive_t NAME;
  61 #define __rtld_lock_define_recursive(CLASS,NAME) \
  62   CLASS __rtld_lock_recursive_t NAME;
  63
  64 /* Define an initialized lock variable NAME with storage class CLASS.
  65
  66    For the C library we take a deeper look at the initializer.  For
  67    this implementation all fields are initialized to zero.  Therefore
  68    we don't initialize the variable which allows putting it into the
  69    BSS section.  (Except on PA-RISC and other odd architectures, where
  70    initialized locks must be set to one due to the lack of normal
  71    atomic operations.) */
  72
  73 #if __LT_SPINLOCK_INIT == 0
  74 #  define __libc_lock_define_initialized(CLASS,NAME) \
  75   CLASS __libc_lock_t NAME;
  76 #else
  77 #  define __libc_lock_define_initialized(CLASS,NAME) \
  78   CLASS __libc_lock_t NAME = PTHREAD_MUTEX_INITIALIZER;
  79 #endif
  80
  81 #define __libc_rwlock_define_initialized(CLASS,NAME) \
  82   CLASS __libc_rwlock_t NAME = PTHREAD_RWLOCK_INITIALIZER;
  83
  84 /* Define an initialized recursive lock variable NAME with storage
  85    class CLASS.  */
  86 #define __libc_lock_define_initialized_recursive(CLASS,NAME) \
  87   CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;
  88 #define _LIBC_LOCK_RECURSIVE_INITIALIZER \
  89   {PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP}
  90
  91 #define __rtld_lock_define_initialized_recursive(CLASS,NAME) \
  92   CLASS __rtld_lock_recursive_t NAME = _RTLD_LOCK_RECURSIVE_INITIALIZER;
  93 #define _RTLD_LOCK_RECURSIVE_INITIALIZER \
  94   {PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP}
  95
  96 #if defined _LIBC && defined IS_IN_libpthread
  97 # define __libc_maybe_call(FUNC, ARGS, ELSE) FUNC ARGS
  98 #else
  99 # if defined __PIC__ || (defined _LIBC && defined SHARED)
 100 #  define __libc_maybe_call(FUNC, ARGS, ELSE) \
 101   (__extension__ ({ __typeof (FUNC) *_fn = (FUNC); \
 102                     _fn != NULL ? (*_fn) ARGS : ELSE; }))
 103 # else
 104 #  define __libc_maybe_call(FUNC, ARGS, ELSE) \
 105   (FUNC != NULL ? FUNC ARGS : ELSE)
 106 # endif
 107 #endif
 108 #if defined _LIBC && !defined NOT_IN_libc && defined SHARED
 109 # define __libc_maybe_call2(FUNC, ARGS, ELSE) \
 110   ({__builtin_expect (__libc_pthread_functions.ptr_##FUNC != NULL, 0) \
 111     ? __libc_pthread_functions.ptr_##FUNC ARGS : ELSE; })
 112 #else
 113 # define __libc_maybe_call2(FUNC, ARGS, ELSE) __libc_maybe_call (__##FUNC, ARGS, ELSE)
 114 #endif
 115
 116 /* Initialize the named lock variable, leaving it in a consistent, unlocked
 117    state.  */
 118 #if defined _LIBC && !defined NOT_IN_libc && defined SHARED
 119 #define __libc_lock_init(NAME) \
 120   ({                                                                          \
 121     (NAME).__m_count = 0;                                                     \
 122     (NAME).__m_owner = NULL;                                                  \
 123     (NAME).__m_kind = PTHREAD_MUTEX_TIMED_NP;                                 \
 124     (NAME).__m_lock.__status = 0;                                             \
 125     (NAME).__m_lock.__spinlock = __LT_SPINLOCK_INIT;                          \
 126     0; })
 127 #else
 128 #define __libc_lock_init(NAME) \
 129   (__libc_maybe_call2 (pthread_mutex_init, (&(NAME), NULL), 0))
 130 #endif
 131 #define __libc_rwlock_init(NAME) \
 132   (__libc_maybe_call (__pthread_rwlock_init, (&(NAME), NULL), 0));
 133
 134 /* Same as last but this time we initialize a recursive mutex.  */
 135 #if defined _LIBC && !defined NOT_IN_libc && defined SHARED
 136 #define __libc_lock_init_recursive(NAME) \
 137   ({                                                                          \
 138     (NAME).mutex.__m_count = 0;                                               \
 139     (NAME).mutex.__m_owner = NULL;                                            \
 140     (NAME).mutex.__m_kind = PTHREAD_MUTEX_RECURSIVE_NP;                       \
 141     (NAME).mutex.__m_lock.__status = 0;                                       \
 142     (NAME).mutex.__m_lock.__spinlock = __LT_SPINLOCK_INIT;                    \
 143     0; })
 144 #else
 145 #define __libc_lock_init_recursive(NAME) \
 146   do {                                                                        \
 147     if (__pthread_mutex_init != NULL)                                         \
 148       {                                                                       \
 149         pthread_mutexattr_t __attr;                                           \
 150         __pthread_mutexattr_init (&__attr);                                   \
 151         __pthread_mutexattr_settype (&__attr, PTHREAD_MUTEX_RECURSIVE_NP); \
 152         __pthread_mutex_init (&(NAME).mutex, &__attr);                        \
 153         __pthread_mutexattr_destroy (&__attr);                                \
 154       }                                                                       \
 155   } while (0);
 156 #endif
 157 #define __rtld_lock_init_recursive(NAME) \
 158   __libc_lock_init_recursive (NAME)
 159
 160 /* Finalize the named lock variable, which must be locked.  It cannot be
 161    used again until __libc_lock_init is called again on it.  This must be
 162    called on a lock variable before the containing storage is reused.  */
 163 #define __libc_lock_fini(NAME) \
 164   (__libc_maybe_call2 (pthread_mutex_destroy, (&(NAME)), 0));
 165 #define __libc_rwlock_fini(NAME) \
 166   (__libc_maybe_call (__pthread_rwlock_destroy, (&(NAME)), 0));
 167
 168 /* Finalize recursive named lock.  */
 169 #define __libc_lock_fini_recursive(NAME) __libc_lock_fini ((NAME).mutex)
 170 #define __rtld_lock_fini_recursive(NAME) __libc_lock_fini_recursive (NAME)
 171
 172 /* Lock the named lock variable.  */
 173 #define __libc_lock_lock(NAME) \
 174   (__libc_maybe_call2 (pthread_mutex_lock, (&(NAME)), 0));
 175 #define __libc_rwlock_rdlock(NAME) \
 176   (__libc_maybe_call (__pthread_rwlock_rdlock, (&(NAME)), 0));
 177 #define __libc_rwlock_wrlock(NAME) \
 178   (__libc_maybe_call (__pthread_rwlock_wrlock, (&(NAME)), 0));
 179
 180 /* Lock the recursive named lock variable.  */
 181 #define __libc_lock_lock_recursive(NAME) __libc_lock_lock ((NAME).mutex)
 182
 183 /* Try to lock the named lock variable.  */
 184 #define __libc_lock_trylock(NAME) \
 185   (__libc_maybe_call2 (pthread_mutex_trylock, (&(NAME)), 0))
 186 #define __libc_rwlock_tryrdlock(NAME) \
 187   (__libc_maybe_call (__pthread_rwlock_tryrdlock, (&(NAME)), 0))
 188 #define __libc_rwlock_trywrlock(NAME) \
 189   (__libc_maybe_call (__pthread_rwlock_trywrlock, (&(NAME)), 0))
 190
 191 /* Try to lock the recursive named lock variable.  */
 192 #define __libc_lock_trylock_recursive(NAME) __libc_lock_trylock ((NAME).mutex)
 193 #define __rtld_lock_trylock_recursive(NAME) \
 194   __libc_lock_trylock_recursive (NAME)
 195
 196 /* Unlock the named lock variable.  */
 197 #define __libc_lock_unlock(NAME) \
 198   (__libc_maybe_call2 (pthread_mutex_unlock, (&(NAME)), 0));
 199 #define __libc_rwlock_unlock(NAME) \
 200   (__libc_maybe_call (__pthread_rwlock_unlock, (&(NAME)), 0));
 201
 202 /* Unlock the recursive named lock variable.  */
 203 #define __libc_lock_unlock_recursive(NAME) __libc_lock_unlock ((NAME).mutex)
 204
 205 #if defined _LIBC && defined SHARED
 206 # define __rtld_lock_default_lock_recursive(lock) \
 207   ++((pthread_mutex_t *)(lock))->__m_count;
 208
 209 # define __rtld_lock_default_unlock_recursive(lock) \
 210   --((pthread_mutex_t *)(lock))->__m_count;
 211
 212 # define __rtld_lock_lock_recursive(NAME) \
 213   GL(dl_rtld_lock_recursive) (&(NAME).mutex)
 214
 215 # define __rtld_lock_unlock_recursive(NAME) \
 216   GL(dl_rtld_unlock_recursive) (&(NAME).mutex)
 217 #else
 218 #define __rtld_lock_lock_recursive(NAME) __libc_lock_lock_recursive (NAME)
 219 #define __rtld_lock_unlock_recursive(NAME) __libc_lock_unlock_recursive (NAME)
 220 #endif
 221
 222 /* Define once control variable.  */
 223 #if PTHREAD_ONCE_INIT == 0
 224 /* Special case for static variables where we can avoid the initialization
 225    if it is zero.  */
 226 # define __libc_once_define(CLASS, NAME) \
 227   CLASS pthread_once_t NAME
 228 #else
 229 # define __libc_once_define(CLASS, NAME) \
 230   CLASS pthread_once_t NAME = PTHREAD_ONCE_INIT
 231 #endif
 232
 233 /* Call handler iff the first call.  */
 234 #define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
 235   do {                                                                        \
 236     if (__pthread_once != NULL)                                               \
 237       __pthread_once (&(ONCE_CONTROL), (INIT_FUNCTION));                      \
 238     else if ((ONCE_CONTROL) == PTHREAD_ONCE_INIT) {                           \
 239       INIT_FUNCTION ();                                                       \
 240       (ONCE_CONTROL) = 2;                                                     \
 241     }                                                                         \
 242   } while (0)
 243
 244
 245 /* Start critical region with cleanup.  */
 246 #define __libc_cleanup_region_start(DOIT, FCT, ARG) \
 247   { struct _pthread_cleanup_buffer _buffer;                                   \
 248     int _avail = (DOIT) && _pthread_cleanup_push_defer != NULL;               \
 249     if (_avail) {                                                             \
 250       _pthread_cleanup_push_defer (&_buffer, (FCT), (ARG));                   \
 251     }
 252
 253 /* End critical region with cleanup.  */
 254 #define __libc_cleanup_region_end(DOIT) \
 255     if (_avail) {                                                             \
 256       _pthread_cleanup_pop_restore (&_buffer, (DOIT));                        \
 257     }                                                                         \
 258   }
 259
 260 /* Sometimes we have to exit the block in the middle.  */
 261 #define __libc_cleanup_end(DOIT) \
 262     if (_avail) {                                                             \
 263       _pthread_cleanup_pop_restore (&_buffer, (DOIT));                        \
 264     }
 265
 266 #define __libc_cleanup_push(fct, arg) \
 267     { struct _pthread_cleanup_buffer _buffer;                                 \
 268     __libc_maybe_call (_pthread_cleanup_push, (&_buffer, (fct), (arg)), 0)
 269
 270 #define __libc_cleanup_pop(execute) \
 271     __libc_maybe_call (_pthread_cleanup_pop, (&_buffer, execute), 0);         \
 272     }
 273
 274 /* Create thread-specific key.  */
 275 #define __libc_key_create(KEY, DESTRUCTOR) \
 276   (__libc_maybe_call (__pthread_key_create, (KEY, DESTRUCTOR), 1))
 277
 278 /* Get thread-specific data.  */
 279 #define __libc_getspecific(KEY) \
 280   (__libc_maybe_call (__pthread_getspecific, (KEY), NULL))
 281
 282 /* Set thread-specific data.  */
 283 #define __libc_setspecific(KEY, VALUE) \
 284   (__libc_maybe_call (__pthread_setspecific, (KEY, VALUE), 0))
 285
 286
 287 /* Register handlers to execute before and after `fork'.  */
 288 #define __libc_atfork(PREPARE, PARENT, CHILD) \
 289   (__libc_maybe_call (__pthread_atfork, (PREPARE, PARENT, CHILD), 0))
 290
 291 /* Functions that are used by this file and are internal to the GNU C
 292    library.  */
 293
 294 extern int __pthread_mutex_init (pthread_mutex_t *__mutex,
 295                                  const pthread_mutexattr_t *__mutex_attr);
 296
 297 extern int __pthread_mutex_destroy (pthread_mutex_t *__mutex);
 298
 299 extern int __pthread_mutex_trylock (pthread_mutex_t *__mutex);
 300
 301 extern int __pthread_mutex_lock (pthread_mutex_t *__mutex);
 302
 303 extern int __pthread_mutex_unlock (pthread_mutex_t *__mutex);
 304
 305 extern int __pthread_mutexattr_init (pthread_mutexattr_t *__attr);
 306
 307 extern int __pthread_mutexattr_destroy (pthread_mutexattr_t *__attr);
 308
 309 extern int __pthread_mutexattr_settype (pthread_mutexattr_t *__attr,
 310                                         int __kind);
 311
 312 #ifdef __USE_UNIX98
 313 extern int __pthread_rwlock_init (pthread_rwlock_t *__rwlock,
 314                                   const pthread_rwlockattr_t *__attr);
 315
 316 extern int __pthread_rwlock_destroy (pthread_rwlock_t *__rwlock);
 317
 318 extern int __pthread_rwlock_rdlock (pthread_rwlock_t *__rwlock);
 319
 320 extern int __pthread_rwlock_tryrdlock (pthread_rwlock_t *__rwlock);
 321
 322 extern int __pthread_rwlock_wrlock (pthread_rwlock_t *__rwlock);
 323
 324 extern int __pthread_rwlock_trywrlock (pthread_rwlock_t *__rwlock);
 325
 326 extern int __pthread_rwlock_unlock (pthread_rwlock_t *__rwlock);
 327 #endif
 328
 329 extern int __pthread_key_create (pthread_key_t *__key,
 330                                  void (*__destr_function) (void *));
 331
 332 extern int __pthread_setspecific (pthread_key_t __key,
 333                                   const void *__pointer);
 334
 335 extern void *__pthread_getspecific (pthread_key_t __key);
 336
 337 extern int __pthread_once (pthread_once_t *__once_control,
 338                            void (*__init_routine) (void));
 339
 340 extern int __pthread_atfork (void (*__prepare) (void),
 341                              void (*__parent) (void),
 342                              void (*__child) (void));
 343
 344
 345
 346 /* Make the pthread functions weak so that we can elide them from
 347    single-threaded processes.  */
 348 #ifndef __NO_WEAK_PTHREAD_ALIASES
 349 # ifdef weak_extern
 350 #   define BP_SYM(sym) sym
 351 weak_extern (BP_SYM (__pthread_mutex_init))
 352 weak_extern (BP_SYM (__pthread_mutex_destroy))
 353 weak_extern (BP_SYM (__pthread_mutex_lock))
 354 weak_extern (BP_SYM (__pthread_mutex_trylock))
 355 weak_extern (BP_SYM (__pthread_mutex_unlock))
 356 weak_extern (BP_SYM (__pthread_mutexattr_init))
 357 weak_extern (BP_SYM (__pthread_mutexattr_destroy))
 358 weak_extern (BP_SYM (__pthread_mutexattr_settype))
 359 weak_extern (BP_SYM (__pthread_rwlock_init))
 360 weak_extern (BP_SYM (__pthread_rwlock_destroy))
 361 weak_extern (BP_SYM (__pthread_rwlock_rdlock))
 362 weak_extern (BP_SYM (__pthread_rwlock_tryrdlock))
 363 weak_extern (BP_SYM (__pthread_rwlock_wrlock))
 364 weak_extern (BP_SYM (__pthread_rwlock_trywrlock))
 365 weak_extern (BP_SYM (__pthread_rwlock_unlock))
 366 weak_extern (BP_SYM (__pthread_key_create))
 367 weak_extern (BP_SYM (__pthread_setspecific))
 368 weak_extern (BP_SYM (__pthread_getspecific))
 369 weak_extern (BP_SYM (__pthread_once))
 370 weak_extern (__pthread_initialize)
 371 weak_extern (__pthread_atfork)
 372 weak_extern (BP_SYM (_pthread_cleanup_push))
 373 weak_extern (BP_SYM (_pthread_cleanup_pop))
 374 weak_extern (BP_SYM (_pthread_cleanup_push_defer))
 375 weak_extern (BP_SYM (_pthread_cleanup_pop_restore))
 376 # else
 377 #  pragma weak __pthread_mutex_init
 378 #  pragma weak __pthread_mutex_destroy
 379 #  pragma weak __pthread_mutex_lock
 380 #  pragma weak __pthread_mutex_trylock
 381 #  pragma weak __pthread_mutex_unlock
 382 #  pragma weak __pthread_mutexattr_init
 383 #  pragma weak __pthread_mutexattr_destroy
 384 #  pragma weak __pthread_mutexattr_settype
 385 #  pragma weak __pthread_rwlock_destroy
 386 #  pragma weak __pthread_rwlock_rdlock
 387 #  pragma weak __pthread_rwlock_tryrdlock
 388 #  pragma weak __pthread_rwlock_wrlock
 389 #  pragma weak __pthread_rwlock_trywrlock
 390 #  pragma weak __pthread_rwlock_unlock
 391 #  pragma weak __pthread_key_create
 392 #  pragma weak __pthread_setspecific
 393 #  pragma weak __pthread_getspecific
 394 #  pragma weak __pthread_once
 395 #  pragma weak __pthread_initialize
 396 #  pragma weak __pthread_atfork
 397 #  pragma weak _pthread_cleanup_push_defer
 398 #  pragma weak _pthread_cleanup_pop_restore
 399 #  pragma weak _pthread_cleanup_push
 400 #  pragma weak _pthread_cleanup_pop
 401 # endif
 402 #endif
 403
 404 /* We need portable names for some functions.  E.g., when they are
 405    used as argument to __libc_cleanup_region_start.  */
 406 #define __libc_mutex_unlock __pthread_mutex_unlock
 407
 408 #endif  /* bits/libc-lock.h */