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/* libc-internal interface for mutex locks. Hurd version using Mach cthreads.
Copyright (C) 1996-2014 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
<http://www.gnu.org/licenses/>. */
#ifndef _BITS_LIBC_LOCK_H
#define _BITS_LIBC_LOCK_H 1
#if (_LIBC - 0) || (_CTHREADS_ - 0)
# if (_LIBC - 0)
# include <tls.h>
# endif
#include <cthreads.h>
typedef struct mutex __libc_lock_t;
typedef struct
{
struct mutex mutex;
void *owner;
int count;
} __libc_lock_recursive_t;
typedef __libc_lock_recursive_t __rtld_lock_recursive_t;
extern char __libc_lock_self0[0];
/* We have to hide the __libc_lock_self access behind a function call,
otherwise gcc >= 4.9 would try to prefetch the TLS dereference even before
the __LIBC_NO_TLS test is finished... */
extern void *__libc_get_lock_self(void);
#define __libc_lock_owner_self() (__LIBC_NO_TLS() ? &__libc_lock_self0 : __libc_get_lock_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_define_initialized(CLASS,NAME) \
CLASS __libc_lock_t NAME = MUTEX_INITIALIZER;
/* Initialize the named lock variable, leaving it in a consistent, unlocked
state. */
#define __libc_lock_init(NAME) __mutex_init (&(NAME))
/* 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(NAME) __mutex_unlock (&(NAME))
#define __libc_lock_fini_recursive(NAME) __mutex_unlock (&(NAME).mutex)
#define __rtld_lock_fini_recursive(NAME) __mutex_unlock (&(NAME).mutex)
/* Lock the named lock variable. */
#define __libc_lock_lock(NAME) __mutex_lock (&(NAME))
/* Lock the named lock variable. */
#define __libc_lock_trylock(NAME) (!__mutex_trylock (&(NAME)))
/* Unlock the named lock variable. */
#define __libc_lock_unlock(NAME) __mutex_unlock (&(NAME))
#define __libc_lock_define_recursive(CLASS,NAME) \
CLASS __libc_lock_recursive_t NAME;
#define _LIBC_LOCK_RECURSIVE_INITIALIZER { MUTEX_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) \
({ __libc_lock_recursive_t *const __lock = &(NAME); \
__lock->owner = 0; mutex_init (&__lock->mutex); })
#define __libc_lock_trylock_recursive(NAME) \
({ __libc_lock_recursive_t *const __lock = &(NAME); \
void *__self = __libc_lock_owner_self (); \
__mutex_trylock (&__lock->mutex) \
? (__lock->owner = __self, __lock->count = 1, 0) \
: __lock->owner == __self ? (++__lock->count, 0) : 1; })
#define __libc_lock_lock_recursive(NAME) \
({ __libc_lock_recursive_t *const __lock = &(NAME); \
void *__self = __libc_lock_owner_self (); \
if (__mutex_trylock (&__lock->mutex) \
|| (__lock->owner != __self \
&& (__mutex_lock (&__lock->mutex), 1))) \
__lock->owner = __self, __lock->count = 1; \
else \
++__lock->count; \
})
#define __libc_lock_unlock_recursive(NAME) \
({ __libc_lock_recursive_t *const __lock = &(NAME); \
if (--__lock->count == 0) \
{ \
__lock->owner = 0; \
__mutex_unlock (&__lock->mutex); \
} \
})
#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
/* Start a critical region with a cleanup function */
#define __libc_cleanup_region_start(DOIT, FCT, ARG) \
{ \
typeof (***(FCT)) *__save_FCT = (DOIT) ? (FCT) : 0; \
typeof (ARG) __save_ARG = ARG; \
/* close brace is in __libc_cleanup_region_end below. */
/* End a critical region started with __libc_cleanup_region_start. */
#define __libc_cleanup_region_end(DOIT) \
if ((DOIT) && __save_FCT != 0) \
(*__save_FCT)(__save_ARG); \
}
/* Sometimes we have to exit the block in the middle. */
#define __libc_cleanup_end(DOIT) \
if ((DOIT) && __save_FCT != 0) \
(*__save_FCT)(__save_ARG); \
#define __libc_cleanup_push(fct, arg) __libc_cleanup_region_start (1, fct, arg)
#define __libc_cleanup_pop(execute) __libc_cleanup_region_end (execute)
#if (_CTHREADS_ - 0)
/* 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 = { MUTEX_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 __mutex_unlock
#endif
/* Type for key of thread specific data. */
typedef cthread_key_t __libc_key_t;
#define __libc_key_create(KEY,DEST) cthread_keycreate (KEY)
#define __libc_setspecific(KEY,VAL) cthread_setspecific (KEY, VAL)
void *__libc_getspecific (__libc_key_t key);
#endif /* _CTHREADS_ */
/* Hide the definitions which are only supposed to be used inside libc in
a separate file. This file is not present in the installation! */
#ifdef _LIBC
# include <bits/libc-lockP.h>
#endif
#endif /* bits/libc-lock.h */
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