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/* Copyright (C) 1994-2018 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 _LOCK_INTERN_H
#define _LOCK_INTERN_H
#include <sys/cdefs.h>
#include <machine-lock.h>
#ifndef _EXTERN_INLINE
#define _EXTERN_INLINE __extern_inline
#endif
/* Initialize LOCK. */
_EXTERN_INLINE void
__spin_lock_init (__spin_lock_t *__lock)
{
*__lock = __SPIN_LOCK_INITIALIZER;
}
/* Lock LOCK, blocking if we can't get it. */
extern void __spin_lock_solid (__spin_lock_t *__lock);
/* Lock the spin lock LOCK. */
_EXTERN_INLINE void
__spin_lock (__spin_lock_t *__lock)
{
if (! __spin_try_lock (__lock))
__spin_lock_solid (__lock);
}
/* Name space-clean internal interface to mutex locks.
Code internal to the C library uses these functions to lock and unlock
mutex locks. These locks are of type `struct mutex', defined in
<cthreads.h>. The functions here are name space-clean. If the program
is linked with the cthreads library, `__mutex_lock_solid' and
`__mutex_unlock_solid' will invoke the corresponding cthreads functions
to implement real mutex locks. If not, simple stub versions just use
spin locks. */
/* Initialize the newly allocated mutex lock LOCK for further use. */
extern void __mutex_init (void *__lock);
/* Lock LOCK, blocking if we can't get it. */
extern void __mutex_lock_solid (void *__lock);
/* Finish unlocking LOCK, after the spin lock LOCK->held has already been
unlocked. This function will wake up any thread waiting on LOCK. */
extern void __mutex_unlock_solid (void *__lock);
/* Lock the mutex lock LOCK. */
_EXTERN_INLINE void
__mutex_lock (void *__lock)
{
if (! __spin_try_lock ((__spin_lock_t *) __lock))
__mutex_lock_solid (__lock);
}
/* Unlock the mutex lock LOCK. */
_EXTERN_INLINE void
__mutex_unlock (void *__lock)
{
__spin_unlock ((__spin_lock_t *) __lock);
__mutex_unlock_solid (__lock);
}
_EXTERN_INLINE int
__mutex_trylock (void *__lock)
{
return __spin_try_lock ((__spin_lock_t *) __lock);
}
#endif /* lock-intern.h */
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