sysdeps/htl/libc-lockP.h

   1 /* Private libc-internal interface for mutex locks.
   2    Copyright (C) 2015-2023 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 License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    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; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _BITS_LIBC_LOCKP_H
  20 #define _BITS_LIBC_LOCKP_H 1
  21
  22 #include <pthread.h>
  23 #include <pthread-functions.h>
  24
  25 /* If we check for a weakly referenced symbol and then perform a
  26    normal jump to it te code generated for some platforms in case of
  27    PIC is unnecessarily slow.  What would happen is that the function
  28    is first referenced as data and then it is called indirectly
  29    through the PLT.  We can make this a direct jump.  */
  30 #ifdef __PIC__
  31 # define __libc_maybe_call(FUNC, ARGS, ELSE) \
  32   (__extension__ ({ __typeof (FUNC) *_fn = (FUNC); \
  33                     _fn != NULL ? (*_fn) ARGS : ELSE; }))
  34 #else
  35 # define __libc_maybe_call(FUNC, ARGS, ELSE) \
  36   (FUNC != NULL ? FUNC ARGS : ELSE)
  37 #endif
  38
  39 /* Call thread functions through the function pointer table.  */
  40 #if defined SHARED && IS_IN (libc)
  41 # define PTFAVAIL(NAME) __libc_pthread_functions_init
  42 # define __libc_ptf_call(FUNC, ARGS, ELSE) \
  43   (__libc_pthread_functions_init ? PTHFCT_CALL (ptr_##FUNC, ARGS) : ELSE)
  44 # define __libc_ptf_call_always(FUNC, ARGS) \
  45   PTHFCT_CALL (ptr_##FUNC, ARGS)
  46 #elif IS_IN (libpthread)
  47 # define PTFAVAIL(NAME) 1
  48 # define __libc_ptf_call(FUNC, ARGS, ELSE) \
  49   FUNC ARGS
  50 # define __libc_ptf_call_always(FUNC, ARGS) \
  51   FUNC ARGS
  52 #else
  53 # define PTFAVAIL(NAME) (NAME != NULL)
  54 # define __libc_ptf_call(FUNC, ARGS, ELSE) \
  55   __libc_maybe_call (FUNC, ARGS, ELSE)
  56 # define __libc_ptf_call_always(FUNC, ARGS) \
  57   FUNC ARGS
  58 #endif
  59
  60 /* Create thread-specific key.  */
  61 #define __libc_key_create(KEY, DESTRUCTOR) \
  62   __libc_ptf_call (__pthread_key_create, (KEY, DESTRUCTOR), 1)
  63
  64 /* Get thread-specific data.  */
  65 #define __libc_getspecific(KEY) \
  66   __libc_ptf_call (__pthread_getspecific, (KEY), NULL)
  67
  68 /* Set thread-specific data.  */
  69 #define __libc_setspecific(KEY, VALUE) \
  70   __libc_ptf_call (__pthread_setspecific, (KEY, VALUE), 0)
  71
  72
  73 /* Functions that are used by this file and are internal to the GNU C
  74    library.  */
  75
  76 extern int __pthread_mutex_init (pthread_mutex_t *__mutex,
  77                                  const pthread_mutexattr_t *__mutex_attr);
  78
  79 extern int __pthread_mutex_destroy (pthread_mutex_t *__mutex);
  80
  81 extern int __pthread_mutex_trylock (pthread_mutex_t *__mutex);
  82
  83 extern int __pthread_mutex_lock (pthread_mutex_t *__mutex);
  84
  85 extern int __pthread_mutex_unlock (pthread_mutex_t *__mutex);
  86
  87 extern int __pthread_mutexattr_init (pthread_mutexattr_t *__attr);
  88
  89 extern int __pthread_mutexattr_destroy (pthread_mutexattr_t *__attr);
  90
  91 extern int __pthread_mutexattr_settype (pthread_mutexattr_t *__attr,
  92                                         int __kind);
  93
  94 extern int __pthread_rwlock_init (pthread_rwlock_t *__rwlock,
  95                                   const pthread_rwlockattr_t *__attr);
  96
  97 extern int __pthread_rwlock_destroy (pthread_rwlock_t *__rwlock);
  98
  99 extern int __pthread_rwlock_rdlock (pthread_rwlock_t *__rwlock);
 100
 101 extern int __pthread_rwlock_tryrdlock (pthread_rwlock_t *__rwlock);
 102
 103 extern int __pthread_rwlock_wrlock (pthread_rwlock_t *__rwlock);
 104
 105 extern int __pthread_rwlock_trywrlock (pthread_rwlock_t *__rwlock);
 106
 107 extern int __pthread_rwlock_unlock (pthread_rwlock_t *__rwlock);
 108
 109 extern int __pthread_once (pthread_once_t *__once_control,
 110                            void (*__init_routine) (void));
 111
 112 extern int __pthread_atfork (void (*__prepare) (void),
 113                              void (*__parent) (void),
 114                              void (*__child) (void));
 115
 116
 117
 118 /* Make the pthread functions weak so that we can elide them from
 119    single-threaded processes.  */
 120 #if !defined(__NO_WEAK_PTHREAD_ALIASES) && !IS_IN (libpthread)
 121 # ifdef weak_extern
 122 weak_extern (__pthread_mutex_init)
 123 weak_extern (__pthread_mutex_destroy)
 124 weak_extern (__pthread_mutex_lock)
 125 weak_extern (__pthread_mutex_trylock)
 126 weak_extern (__pthread_mutex_unlock)
 127 weak_extern (__pthread_mutexattr_init)
 128 weak_extern (__pthread_mutexattr_destroy)
 129 weak_extern (__pthread_mutexattr_settype)
 130 weak_extern (__pthread_rwlock_init)
 131 weak_extern (__pthread_rwlock_destroy)
 132 weak_extern (__pthread_rwlock_rdlock)
 133 weak_extern (__pthread_rwlock_tryrdlock)
 134 weak_extern (__pthread_rwlock_wrlock)
 135 weak_extern (__pthread_rwlock_trywrlock)
 136 weak_extern (__pthread_rwlock_unlock)
 137 weak_extern (__pthread_key_create)
 138 weak_extern (__pthread_setspecific)
 139 weak_extern (__pthread_getspecific)
 140 weak_extern (__pthread_once)
 141 weak_extern (__pthread_initialize)
 142 weak_extern (__pthread_atfork)
 143 weak_extern (__pthread_setcancelstate)
 144 # else
 145 #  pragma weak __pthread_mutex_init
 146 #  pragma weak __pthread_mutex_destroy
 147 #  pragma weak __pthread_mutex_lock
 148 #  pragma weak __pthread_mutex_trylock
 149 #  pragma weak __pthread_mutex_unlock
 150 #  pragma weak __pthread_mutexattr_init
 151 #  pragma weak __pthread_mutexattr_destroy
 152 #  pragma weak __pthread_mutexattr_settype
 153 #  pragma weak __pthread_rwlock_destroy
 154 #  pragma weak __pthread_rwlock_rdlock
 155 #  pragma weak __pthread_rwlock_tryrdlock
 156 #  pragma weak __pthread_rwlock_wrlock
 157 #  pragma weak __pthread_rwlock_trywrlock
 158 #  pragma weak __pthread_rwlock_unlock
 159 #  pragma weak __pthread_key_create
 160 #  pragma weak __pthread_setspecific
 161 #  pragma weak __pthread_getspecific
 162 #  pragma weak __pthread_once
 163 #  pragma weak __pthread_initialize
 164 #  pragma weak __pthread_atfork
 165 #  pragma weak __pthread_setcancelstate
 166 # endif
 167 #endif
 168
 169 #endif  /* bits/libc-lockP.h */