sysdeps/mach/bits/libc-lock.h

   1 /* libc-internal interface for mutex locks.  Mach cthreads version.
   2    Copyright (C) 1996,97,98,2000,01, 2002 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _BITS_LIBC_LOCK_H
  21 #define _BITS_LIBC_LOCK_H 1
  22
  23 #ifdef _LIBC
  24 #include <cthreads.h>
  25 #define __libc_lock_t struct mutex
  26 #else
  27 typedef struct __libc_lock_opaque__ __libc_lock_t;
  28 #endif
  29
  30 /* Type for key of thread specific data.  */
  31 typedef cthread_key_t __libc_key_t;
  32
  33 /* Define a lock variable NAME with storage class CLASS.  The lock must be
  34    initialized with __libc_lock_init before it can be used (or define it
  35    with __libc_lock_define_initialized, below).  Use `extern' for CLASS to
  36    declare a lock defined in another module.  In public structure
  37    definitions you must use a pointer to the lock structure (i.e., NAME
  38    begins with a `*'), because its storage size will not be known outside
  39    of libc.  */
  40 #define __libc_lock_define(CLASS,NAME) \
  41   CLASS __libc_lock_t NAME;
  42
  43 /* Define an initialized lock variable NAME with storage class CLASS.  */
  44 #define __libc_lock_define_initialized(CLASS,NAME) \
  45   CLASS __libc_lock_t NAME = MUTEX_INITIALIZER;
  46
  47 /* Initialize the named lock variable, leaving it in a consistent, unlocked
  48    state.  */
  49 #define __libc_lock_init(NAME) __mutex_init (&(NAME))
  50
  51 /* Finalize the named lock variable, which must be locked.  It cannot be
  52    used again until __libc_lock_init is called again on it.  This must be
  53    called on a lock variable before the containing storage is reused.  */
  54 #define __libc_lock_fini(NAME) __mutex_unlock (&(NAME))
  55
  56 /* Lock the named lock variable.  */
  57 #define __libc_lock_lock(NAME) __mutex_lock (&(NAME))
  58
  59 /* Lock the named lock variable.  */
  60 #define __libc_lock_trylock(NAME) (!__mutex_trylock (&(NAME)))
  61
  62 /* Unlock the named lock variable.  */
  63 #define __libc_lock_unlock(NAME) __mutex_unlock (&(NAME))
  64
  65
  66 /* XXX for now */
  67 #define __libc_rwlock_define            __libc_lock_define
  68 #define __libc_rwlock_define_initialized __libc_lock_define_initialized
  69 #define __libc_rwlock_init              __libc_lock_init
  70 #define __libc_rwlock_fini              __libc_lock_fini
  71 #define __libc_rwlock_rdlock            __libc_lock_lock
  72 #define __libc_rwlock_wrlock            __libc_lock_lock
  73 #define __libc_rwlock_tryrdlock         __libc_lock_trylock
  74 #define __libc_rwlock_trywrlock         __libc_lock_trylock
  75 #define __libc_rwlock_unlock            __libc_lock_unlock
  76
  77
  78 /* Start a critical region with a cleanup function */
  79 #define __libc_cleanup_region_start(DOIT, FCT, ARG)                         \
  80 {                                                                           \
  81   typeof (***(FCT)) *__save_FCT = (DOIT) ? (FCT) : 0;                       \
  82   typeof (ARG) __save_ARG = ARG;                                            \
  83   /* close brace is in __libc_cleanup_region_end below. */
  84
  85 /* End a critical region started with __libc_cleanup_region_start. */
  86 #define __libc_cleanup_region_end(DOIT)                                     \
  87   if ((DOIT) && __save_FCT != 0)                                            \
  88     (*__save_FCT)(__save_ARG);                                              \
  89 }
  90
  91 /* Sometimes we have to exit the block in the middle.  */
  92 #define __libc_cleanup_end(DOIT)                                            \
  93   if ((DOIT) && __save_FCT != 0)                                            \
  94     (*__save_FCT)(__save_ARG);                                              \
  95
  96
  97 /* Use mutexes as once control variables. */
  98
  99 struct __libc_once
 100   {
 101     __libc_lock_t lock;
 102     int done;
 103   };
 104
 105 #define __libc_once_define(CLASS,NAME) \
 106   CLASS struct __libc_once NAME = { MUTEX_INITIALIZER, 0 }
 107
 108
 109 /* Call handler iff the first call.  */
 110 #define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
 111   do {                                                                        \
 112     __libc_lock_lock (ONCE_CONTROL.lock);                                     \
 113     if (!ONCE_CONTROL.done)                                                   \
 114       (INIT_FUNCTION) ();                                                     \
 115     ONCE_CONTROL.done = 1;                                                    \
 116     __libc_lock_unlock (ONCE_CONTROL.lock);                                   \
 117   } while (0)
 118
 119 #ifdef _LIBC
 120 /* We need portable names for some functions.  E.g., when they are
 121    used as argument to __libc_cleanup_region_start.  */
 122 #define __libc_mutex_unlock __mutex_unlock
 123 #endif
 124
 125 #define __libc_key_create(KEY,DEST) cthread_keycreate (KEY)
 126 #define __libc_setspecific(KEY,VAL) cthread_setspecific (KEY, VAL)
 127 void *__libc_getspecific (__libc_key_t key);
 128
 129 /* XXX until cthreads supports recursive locks */
 130 #define __libc_lock_define_initialized_recursive __libc_lock_define_initialized
 131 #define __libc_lock_init_recursive __libc_lock_init
 132 #define __libc_lock_fini_recursive __libc_lock_fini
 133 #define __libc_lock_trylock_recursive __libc_lock_trylock
 134 #define __libc_lock_unlock_recursive __libc_lock_unlock
 135 #define __libc_lock_lock_recursive __libc_lock_lock
 136
 137 #define __rtld_lock_define_initialized_recursive __libc_lock_define_initialized
 138 #define __rtld_lock_init_recursive __libc_lock_init
 139 #define __rtld_lock_fini_recursive __libc_lock_fini
 140 #define __rtld_lock_trylock_recursive __libc_lock_trylock
 141 #define __rtld_lock_unlock_recursive __libc_lock_unlock
 142 #define __rtld_lock_lock_recursive __libc_lock_lock
 143
 144 #endif  /* bits/libc-lock.h */