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