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217 lines
7.8 KiB
C
217 lines
7.8 KiB
C
/* libc-internal interface for mutex locks. Hurd version using Mach cthreads.
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Copyright (C) 1996-2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _LIBC_LOCK_H
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#define _LIBC_LOCK_H 1
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#if (_LIBC - 0) || (_CTHREADS_ - 0)
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#include <cthreads.h>
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#include <hurd/threadvar.h>
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/* The locking here is very inexpensive, even for inlining. */
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#define _IO_lock_inexpensive 1
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typedef struct mutex __libc_lock_t;
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typedef struct
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{
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struct mutex mutex;
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void *owner;
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int count;
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} __libc_lock_recursive_t;
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typedef __libc_lock_recursive_t __rtld_lock_recursive_t;
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#define __libc_lock_owner_self() ((void *) __hurd_threadvar_location (0))
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#else
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typedef struct __libc_lock_opaque__ __libc_lock_t;
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typedef struct __libc_lock_recursive_opaque__ __libc_lock_recursive_t;
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#endif
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/* Define a lock variable NAME with storage class CLASS. The lock must be
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initialized with __libc_lock_init before it can be used (or define it
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with __libc_lock_define_initialized, below). Use `extern' for CLASS to
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declare a lock defined in another module. In public structure
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definitions you must use a pointer to the lock structure (i.e., NAME
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begins with a `*'), because its storage size will not be known outside
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of libc. */
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#define __libc_lock_define(CLASS,NAME) \
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CLASS __libc_lock_t NAME;
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/* Define an initialized lock variable NAME with storage class CLASS. */
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#define _LIBC_LOCK_INITIALIZER MUTEX_INITIALIZER
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#define __libc_lock_define_initialized(CLASS,NAME) \
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CLASS __libc_lock_t NAME = _LIBC_LOCK_INITIALIZER;
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/* Initialize the named lock variable, leaving it in a consistent, unlocked
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state. */
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#define __libc_lock_init(NAME) __mutex_init (&(NAME))
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/* Finalize the named lock variable, which must be locked. It cannot be
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used again until __libc_lock_init is called again on it. This must be
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called on a lock variable before the containing storage is reused. */
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#define __libc_lock_fini(NAME) __mutex_unlock (&(NAME))
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#define __libc_lock_fini_recursive(NAME) __mutex_unlock (&(NAME).mutex)
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#define __rtld_lock_fini_recursive(NAME) __mutex_unlock (&(NAME).mutex)
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/* Lock the named lock variable. */
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#define __libc_lock_lock(NAME) __mutex_lock (&(NAME))
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/* Lock the named lock variable. */
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#define __libc_lock_trylock(NAME) (!__mutex_trylock (&(NAME)))
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/* Unlock the named lock variable. */
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#define __libc_lock_unlock(NAME) __mutex_unlock (&(NAME))
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#define __libc_lock_define_recursive(CLASS,NAME) \
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CLASS __libc_lock_recursive_t NAME;
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#define _LIBC_LOCK_RECURSIVE_INITIALIZER { MUTEX_INITIALIZER, 0, 0 }
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#define __libc_lock_define_initialized_recursive(CLASS,NAME) \
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CLASS __libc_lock_recursive_t NAME = _LIBC_LOCK_RECURSIVE_INITIALIZER;
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#define __rtld_lock_define_recursive(CLASS,NAME) \
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__libc_lock_define_recursive (CLASS, NAME)
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#define _RTLD_LOCK_RECURSIVE_INITIALIZER \
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_LIBC_LOCK_RECURSIVE_INITIALIZER
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#define __rtld_lock_define_initialized_recursive(CLASS,NAME) \
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__libc_lock_define_initialized_recursive (CLASS, NAME)
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#define __libc_lock_init_recursive(NAME) \
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({ __libc_lock_recursive_t *const __lock = &(NAME); \
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__lock->owner = 0; mutex_init (&__lock->mutex); })
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#define __libc_lock_trylock_recursive(NAME) \
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({ __libc_lock_recursive_t *const __lock = &(NAME); \
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void *__self = __libc_lock_owner_self (); \
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__mutex_trylock (&__lock->mutex) \
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? (__lock->owner = __self, __lock->count = 1, 0) \
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: __lock->owner == __self ? (++__lock->count, 0) : 1; })
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#define __libc_lock_lock_recursive(NAME) \
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({ __libc_lock_recursive_t *const __lock = &(NAME); \
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void *__self = __libc_lock_owner_self (); \
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if (__mutex_trylock (&__lock->mutex) \
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|| (__lock->owner != __self \
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&& (__mutex_lock (&__lock->mutex), 1))) \
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__lock->owner = __self, __lock->count = 1; \
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else \
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++__lock->count; \
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})
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#define __libc_lock_unlock_recursive(NAME) \
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({ __libc_lock_recursive_t *const __lock = &(NAME); \
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if (--__lock->count == 0) \
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{ \
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__lock->owner = 0; \
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__mutex_unlock (&__lock->mutex); \
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} \
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})
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#define __rtld_lock_initialize(NAME) \
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(void) ((NAME) = (__rtld_lock_recursive_t) _RTLD_LOCK_RECURSIVE_INITIALIZER)
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#define __rtld_lock_trylock_recursive(NAME) \
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__libc_lock_trylock_recursive (NAME)
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#define __rtld_lock_lock_recursive(NAME) \
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__libc_lock_lock_recursive(NAME)
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#define __rtld_lock_unlock_recursive(NAME) \
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__libc_lock_unlock_recursive (NAME)
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/* XXX for now */
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#define __libc_rwlock_define __libc_lock_define
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#define __libc_rwlock_define_initialized __libc_lock_define_initialized
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#define __libc_rwlock_init __libc_lock_init
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#define __libc_rwlock_fini __libc_lock_fini
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#define __libc_rwlock_rdlock __libc_lock_lock
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#define __libc_rwlock_wrlock __libc_lock_lock
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#define __libc_rwlock_tryrdlock __libc_lock_trylock
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#define __libc_rwlock_trywrlock __libc_lock_trylock
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#define __libc_rwlock_unlock __libc_lock_unlock
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/* Start a critical region with a cleanup function */
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#define __libc_cleanup_region_start(DOIT, FCT, ARG) \
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{ \
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typeof (***(FCT)) *__save_FCT = (DOIT) ? (FCT) : 0; \
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typeof (ARG) __save_ARG = ARG; \
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/* close brace is in __libc_cleanup_region_end below. */
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/* End a critical region started with __libc_cleanup_region_start. */
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#define __libc_cleanup_region_end(DOIT) \
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if ((DOIT) && __save_FCT != 0) \
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(*__save_FCT)(__save_ARG); \
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}
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/* Sometimes we have to exit the block in the middle. */
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#define __libc_cleanup_end(DOIT) \
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if ((DOIT) && __save_FCT != 0) \
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(*__save_FCT)(__save_ARG); \
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#define __libc_cleanup_push(fct, arg) __libc_cleanup_region_start (1, fct, arg)
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#define __libc_cleanup_pop(execute) __libc_cleanup_region_end (execute)
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#if (_CTHREADS_ - 0)
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/* Use mutexes as once control variables. */
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struct __libc_once
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{
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__libc_lock_t lock;
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int done;
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};
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#define __libc_once_define(CLASS,NAME) \
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CLASS struct __libc_once NAME = { MUTEX_INITIALIZER, 0 }
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/* Call handler iff the first call. */
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#define __libc_once(ONCE_CONTROL, INIT_FUNCTION) \
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do { \
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__libc_lock_lock (ONCE_CONTROL.lock); \
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if (!ONCE_CONTROL.done) \
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(INIT_FUNCTION) (); \
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ONCE_CONTROL.done = 1; \
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__libc_lock_unlock (ONCE_CONTROL.lock); \
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} while (0)
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/* Get once control variable. */
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#define __libc_once_get(ONCE_CONTROL) ((ONCE_CONTROL).done != 0)
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#ifdef _LIBC
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/* We need portable names for some functions. E.g., when they are
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used as argument to __libc_cleanup_region_start. */
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#define __libc_mutex_unlock __mutex_unlock
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#endif
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/* Type for key of thread specific data. */
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typedef cthread_key_t __libc_key_t;
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#define __libc_key_create(KEY,DEST) cthread_keycreate (KEY)
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#define __libc_setspecific(KEY,VAL) cthread_setspecific (KEY, VAL)
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void *__libc_getspecific (__libc_key_t key);
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#endif /* _CTHREADS_ */
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/* Hide the definitions which are only supposed to be used inside libc in
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a separate file. This file is not present in the installation! */
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#ifdef _LIBC
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# include <libc-lockP.h>
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#endif
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#endif /* libc-lock.h */
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