glibc/sysdeps/nptl/stdio-lock.h

111 lines
3.5 KiB
C

/* Thread package specific definitions of stream lock type. NPTL version.
Copyright (C) 2000-2016 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 _STDIO_LOCK_H
#define _STDIO_LOCK_H 1
#include <libc-lock.h>
#include <lowlevellock.h>
/* The locking here is very inexpensive, even for inlining. */
#define _IO_lock_inexpensive 1
typedef struct { int lock; int cnt; void *owner; } _IO_lock_t;
#define _IO_lock_initializer { LLL_LOCK_INITIALIZER, 0, NULL }
#define _IO_lock_init(_name) \
((void) ((_name) = (_IO_lock_t) _IO_lock_initializer))
#define _IO_lock_fini(_name) \
((void) 0)
#define _IO_lock_lock(_name) \
do { \
void *__self = THREAD_SELF; \
if ((_name).owner != __self) \
{ \
lll_lock ((_name).lock, LLL_PRIVATE); \
(_name).owner = __self; \
} \
++(_name).cnt; \
} while (0)
#define _IO_lock_trylock(_name) \
({ \
int __result = 0; \
void *__self = THREAD_SELF; \
if ((_name).owner != __self) \
{ \
if (lll_trylock ((_name).lock) == 0) \
{ \
(_name).owner = __self; \
(_name).cnt = 1; \
} \
else \
__result = EBUSY; \
} \
else \
++(_name).cnt; \
__result; \
})
#define _IO_lock_unlock(_name) \
do { \
if (--(_name).cnt == 0) \
{ \
(_name).owner = NULL; \
lll_unlock ((_name).lock, LLL_PRIVATE); \
} \
} while (0)
#define _IO_cleanup_region_start(_fct, _fp) \
__libc_cleanup_region_start (((_fp)->_flags & _IO_USER_LOCK) == 0, _fct, _fp)
#define _IO_cleanup_region_start_noarg(_fct) \
__libc_cleanup_region_start (1, _fct, NULL)
#define _IO_cleanup_region_end(_doit) \
__libc_cleanup_region_end (_doit)
#if defined _LIBC && IS_IN (libc)
# ifdef __EXCEPTIONS
# define _IO_acquire_lock(_fp) \
do { \
_IO_FILE *_IO_acquire_lock_file \
__attribute__((cleanup (_IO_acquire_lock_fct))) \
= (_fp); \
_IO_flockfile (_IO_acquire_lock_file);
# define _IO_acquire_lock_clear_flags2(_fp) \
do { \
_IO_FILE *_IO_acquire_lock_file \
__attribute__((cleanup (_IO_acquire_lock_clear_flags2_fct))) \
= (_fp); \
_IO_flockfile (_IO_acquire_lock_file);
# else
# define _IO_acquire_lock(_fp) _IO_acquire_lock_needs_exceptions_enabled
# define _IO_acquire_lock_clear_flags2(_fp) _IO_acquire_lock (_fp)
# endif
# define _IO_release_lock(_fp) ; } while (0)
#endif
#endif /* stdio-lock.h */