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/* libc-internal interface for mutex locks. Mach cthreads version.
Copyright (C) 1996-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _LIBC_LOCK_H
#define _LIBC_LOCK_H 1
#ifdef _LIBC
#include <tls.h>
#include <lowlevellock.h>
/* The locking here is very inexpensive, even for inlining. */
#define _IO_lock_inexpensive 1
typedef unsigned int __libc_lock_t;
typedef struct
{
__libc_lock_t lock;
int cnt;
void *owner;
} __libc_lock_recursive_t;
typedef __libc_lock_recursive_t __rtld_lock_recursive_t;
extern char __libc_lock_self0[0];
#define __libc_lock_owner_self() \
(__LIBC_NO_TLS () ? (void *)&__libc_lock_self0 : THREAD_SELF)
#else
typedef struct __libc_lock_opaque__ __libc_lock_t;
typedef struct __libc_lock_recursive_opaque__ __libc_lock_recursive_t;
#endif
/* Define a lock variable NAME with storage class CLASS. The lock must be
initialized with __libc_lock_init before it can be used (or define it
with __libc_lock_define_initialized, below). Use `extern' for CLASS to
declare a lock defined in another module. In public structure
definitions you must use a pointer to the lock structure (i.e., NAME
begins with a `*'), because its storage size will not be known outside
of libc. */
#define __libc_lock_define(CLASS,NAME) \
CLASS __libc_lock_t NAME;
/* Define an initialized lock variable NAME with storage class CLASS. */
#define _LIBC_LOCK_INITIALIZER LLL_LOCK_INITIALIZER
#define __libc_lock_define_initialized(CLASS,NAME) \
CLASS __libc_lock_t NAME = LLL_LOCK_INITIALIZER;
/* Initialize the named lock variable, leaving it in a consistent, unlocked
state. */
#define __libc_lock_init(NAME) (NAME) = LLL_LOCK_INITIALIZER
/* Finalize the named lock variable, which must be locked. It cannot be
used again until __libc_lock_init is called again on it. This must be
called on a lock variable before the containing storage is reused. */
#define __libc_lock_fini __libc_lock_unlock
#define __libc_lock_fini_recursive __libc_lock_unlock_recursive
#define __rtld_lock_fini_recursive __rtld_lock_unlock_recursive
/* Lock the named lock variable. */
#define __libc_lock_lock(NAME) \
({ lll_lock ((NAME), 0); 0; })
/* Lock the named lock variable. */
#define __libc_lock_trylock(NAME) lll_trylock (NAME)
/* Unlock the named lock variable. */
#define __libc_lock_unlock(NAME) \
({ lll_unlock ((NAME), 0); 0; })
#define __libc_lock_define_recursive(CLASS,NAME) \
CLASS __libc_lock_recursive_t NAME;
#define _LIBC_LOCK_RECURSIVE_INITIALIZER { LLL_LOCK_INITIALIZER, 0, 0 }
#define __libc_lock_define_initialized_recursive(CLASS,NAME) \
CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;
#define __rtld_lock_define_recursive(CLASS,NAME) \
__libc_lock_define_recursive (CLASS, NAME)
#define _RTLD_LOCK_RECURSIVE_INITIALIZER \
_LIBC_LOCK_RECURSIVE_INITIALIZER
#define __rtld_lock_define_initialized_recursive(CLASS,NAME) \
__libc_lock_define_initialized_recursive (CLASS, NAME)
#define __libc_lock_init_recursive(NAME) \
({ \
(NAME) = (__libc_lock_recursive_t)_LIBC_LOCK_RECURSIVE_INITIALIZER; \
0; \
})
#define __libc_lock_trylock_recursive(NAME) \
({ \
__libc_lock_recursive_t *const __lock = &(NAME); \
void *__self = __libc_lock_owner_self (); \
int __r = 0; \
if (__self == __lock->owner) \
++__lock->cnt; \
else if ((__r = lll_trylock (__lock->lock)) == 0) \
__lock->owner = __self, __lock->cnt = 1; \
__r; \
})
#define __libc_lock_lock_recursive(NAME) \
({ \
__libc_lock_recursive_t *const __lock = &(NAME); \
void *__self = __libc_lock_owner_self (); \
if (__self != __lock->owner) \
{ \
lll_lock (__lock->lock, 0); \
__lock->owner = __self; \
} \
++__lock->cnt; \
(void)0; \
})
#define __libc_lock_unlock_recursive(NAME) \
({ \
__libc_lock_recursive_t *const __lock = &(NAME); \
if (--__lock->cnt == 0) \
{ \
__lock->owner = 0; \
lll_unlock (__lock->lock, 0); \
} \
})
#define __rtld_lock_initialize(NAME) \
(void) ((NAME) = (__rtld_lock_recursive_t) _RTLD_LOCK_RECURSIVE_INITIALIZER)
#define __rtld_lock_trylock_recursive(NAME) \
__libc_lock_trylock_recursive (NAME)
#define __rtld_lock_lock_recursive(NAME) \
__libc_lock_lock_recursive(NAME)
#define __rtld_lock_unlock_recursive(NAME) \
__libc_lock_unlock_recursive (NAME)
/* XXX for now */
#define __libc_rwlock_define __libc_lock_define
#define __libc_rwlock_define_initialized __libc_lock_define_initialized
#define __libc_rwlock_init __libc_lock_init
#define __libc_rwlock_fini __libc_lock_fini
#define __libc_rwlock_rdlock __libc_lock_lock
#define __libc_rwlock_wrlock __libc_lock_lock
#define __libc_rwlock_tryrdlock __libc_lock_trylock
#define __libc_rwlock_trywrlock __libc_lock_trylock
#define __libc_rwlock_unlock __libc_lock_unlock
struct __libc_cleanup_frame
{
void (*__fct) (void *);
void *__argp;
int __doit;
};
__extern_inline void
__libc_cleanup_fct (struct __libc_cleanup_frame *framep)
{
if (framep->__doit)
framep->__fct (framep->__argp);
}
/* Start a critical region with a cleanup function */
#define __libc_cleanup_region_start(DOIT, FCT, ARG) \
do \
{ \
struct __libc_cleanup_frame __cleanup \
__attribute__ ((__cleanup__ (__libc_cleanup_fct))) = \
{ .__fct = (FCT), .__argp = (ARG), .__doit = (DOIT) };
/* This one closes the brace above. */
#define __libc_cleanup_region_end(DOIT) \
__cleanup.__doit = (DOIT); \
} \
while (0)
#define __libc_cleanup_end(DOIT) __cleanup.__doit = (DOIT);
#define __libc_cleanup_push(fct, arg) __libc_cleanup_region_start (1, fct, arg)
#define __libc_cleanup_pop(execute) __libc_cleanup_region_end (execute)
/* Use mutexes as once control variables. */
struct __libc_once
{
__libc_lock_t lock;
int done;
};
#define __libc_once_define(CLASS,NAME) \
CLASS struct __libc_once NAME = { _LIBC_LOCK_INITIALIZER, 0 }
/* Call handler iff the first call. */
#define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
do { \
__libc_lock_lock (ONCE_CONTROL.lock); \
if (!ONCE_CONTROL.done) \
(INIT_FUNCTION) (); \
ONCE_CONTROL.done = 1; \
__libc_lock_unlock (ONCE_CONTROL.lock); \
} while (0)
/* Get once control variable. */
#define __libc_once_get(ONCE_CONTROL) ((ONCE_CONTROL).done != 0)
#ifdef _LIBC
/* We need portable names for some functions. E.g., when they are
used as argument to __libc_cleanup_region_start. */
#define __libc_mutex_unlock __libc_lock_unlock
/* Hide the definitions which are only supposed to be used inside libc in
a separate file. This file is not present in the installation! */
# include <libc-lockP.h>
#endif
#endif /* libc-lock.h */
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