sysdeps/generic/libc-lock.h

   1 /* libc-internal interface for mutex locks.  Stub version.
   2    Copyright (C) 1996-2016 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
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _LIBC_LOCK_H
  20 #define _LIBC_LOCK_H 1
  21
  22
  23 /* Define a lock variable NAME with storage class CLASS.  The lock must be
  24    initialized with __libc_lock_init before it can be used (or define it
  25    with __libc_lock_define_initialized, below).  Use `extern' for CLASS to
  26    declare a lock defined in another module.  In public structure
  27    definitions you must use a pointer to the lock structure (i.e., NAME
  28    begins with a `*'), because its storage size will not be known outside
  29    of libc.  */
  30 #define __libc_lock_define(CLASS,NAME)
  31 #define __libc_lock_define_recursive(CLASS,NAME)
  32 #define __rtld_lock_define_recursive(CLASS,NAME)
  33 #define __libc_rwlock_define(CLASS,NAME)
  34
  35 /* Define an initialized lock variable NAME with storage class CLASS.  */
  36 #define __libc_lock_define_initialized(CLASS,NAME)
  37 #define __libc_rwlock_define_initialized(CLASS,NAME)
  38
  39 /* Define an initialized recursive lock variable NAME with storage
  40    class CLASS.  */
  41 #define __libc_lock_define_initialized_recursive(CLASS,NAME)
  42 #define __rtld_lock_define_initialized_recursive(CLASS,NAME)
  43
  44 /* Initialize the named lock variable, leaving it in a consistent, unlocked
  45    state.  */
  46 #define __libc_lock_init(NAME)
  47 #define __rtld_lock_initialize(NAME)
  48 #define __libc_rwlock_init(NAME)
  49
  50 /* Same as last but this time we initialize a recursive mutex.  */
  51 #define __libc_lock_init_recursive(NAME)
  52
  53 /* Finalize the named lock variable, which must be locked.  It cannot be
  54    used again until __libc_lock_init is called again on it.  This must be
  55    called on a lock variable before the containing storage is reused.  */
  56 #define __libc_lock_fini(NAME)
  57 #define __libc_rwlock_fini(NAME)
  58
  59 /* Finalize recursive named lock.  */
  60 #define __libc_lock_fini_recursive(NAME)
  61
  62 /* Lock the named lock variable.  */
  63 #define __libc_lock_lock(NAME)
  64 #define __libc_rwlock_rdlock(NAME)
  65 #define __libc_rwlock_wrlock(NAME)
  66
  67 /* Lock the recursive named lock variable.  */
  68 #define __libc_lock_lock_recursive(NAME)
  69 #define __rtld_lock_lock_recursive(NAME)
  70
  71 /* Try to lock the named lock variable.  */
  72 #define __libc_lock_trylock(NAME) 0
  73 #define __libc_rwlock_tryrdlock(NAME) 0
  74 #define __libc_rwlock_trywrlock(NAME) 0
  75
  76 /* Try to lock the recursive named lock variable.  */
  77 #define __libc_lock_trylock_recursive(NAME) 0
  78
  79 /* Unlock the named lock variable.  */
  80 #define __libc_lock_unlock(NAME)
  81 #define __libc_rwlock_unlock(NAME)
  82
  83 /* Unlock the recursive named lock variable.  */
  84 #define __libc_lock_unlock_recursive(NAME)
  85 #define __rtld_lock_unlock_recursive(NAME)
  86
  87
  88 /* Define once control variable.  */
  89 #define __libc_once_define(CLASS, NAME) CLASS int NAME = 0
  90
  91 /* Call handler iff the first call.  */
  92 #define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
  93   do {                                                                        \
  94     if ((ONCE_CONTROL) == 0) {                                                \
  95       INIT_FUNCTION ();                                                       \
  96       (ONCE_CONTROL) = 1;                                                     \
  97     }                                                                         \
  98   } while (0)
  99
 100 /* Get once control variable.  */
 101 #define __libc_once_get(ONCE_CONTROL) \
 102   ((ONCE_CONTROL) == 1)
 103
 104 /* Start a critical region with a cleanup function */
 105 #define __libc_cleanup_region_start(DOIT, FCT, ARG)                         \
 106 {                                                                           \
 107   typeof (***(FCT)) *__save_FCT = (DOIT) ? (FCT) : 0;                       \
 108   typeof (ARG) __save_ARG = ARG;                                            \
 109   /* close brace is in __libc_cleanup_region_end below. */
 110
 111 /* End a critical region started with __libc_cleanup_region_start. */
 112 #define __libc_cleanup_region_end(DOIT)                                     \
 113   if ((DOIT) && __save_FCT != 0)                                            \
 114     (*__save_FCT)(__save_ARG);                                              \
 115 }
 116
 117 /* Sometimes we have to exit the block in the middle.  */
 118 #define __libc_cleanup_end(DOIT)                                            \
 119   if ((DOIT) && __save_FCT != 0)                                            \
 120     (*__save_FCT)(__save_ARG);                                              \
 121
 122 #define __libc_cleanup_push(fct, arg) __libc_cleanup_region_start (1, fct, arg)
 123 #define __libc_cleanup_pop(execute) __libc_cleanup_region_end (execute)
 124
 125 /* We need portable names for some of the functions.  */
 126 #define __libc_mutex_unlock
 127
 128 /* Type for key of thread specific data.  */
 129 typedef int __libc_key_t;
 130
 131 /* Create key for thread specific data.  */
 132 #define __libc_key_create(KEY,DEST)     ((void) (KEY), (void) (DEST), -1)
 133
 134 /* Set thread-specific data associated with KEY to VAL.  */
 135 #define __libc_setspecific(KEY,VAL)     ((void) (KEY), (void) (VAL))
 136
 137 /* Get thread-specific data associated with KEY.  */
 138 #define __libc_getspecific(KEY)         ((void) (KEY), (void *) 0)
 139
 140 #endif  /* libc-lock.h */