97 lines
2.7 KiB
C
97 lines
2.7 KiB
C
/* Copyright (C) 1994-2016 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 _LOCK_INTERN_H
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#define _LOCK_INTERN_H
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#include <sys/cdefs.h>
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#include <machine-lock.h>
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#ifndef _EXTERN_INLINE
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#define _EXTERN_INLINE __extern_inline
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#endif
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/* Initialize LOCK. */
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_EXTERN_INLINE void
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__spin_lock_init (__spin_lock_t *__lock)
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{
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*__lock = __SPIN_LOCK_INITIALIZER;
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}
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/* Lock LOCK, blocking if we can't get it. */
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extern void __spin_lock_solid (__spin_lock_t *__lock);
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/* Lock the spin lock LOCK. */
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_EXTERN_INLINE void
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__spin_lock (__spin_lock_t *__lock)
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{
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if (! __spin_try_lock (__lock))
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__spin_lock_solid (__lock);
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}
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/* Name space-clean internal interface to mutex locks.
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Code internal to the C library uses these functions to lock and unlock
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mutex locks. These locks are of type `struct mutex', defined in
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<cthreads.h>. The functions here are name space-clean. If the program
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is linked with the cthreads library, `__mutex_lock_solid' and
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`__mutex_unlock_solid' will invoke the corresponding cthreads functions
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to implement real mutex locks. If not, simple stub versions just use
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spin locks. */
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/* Initialize the newly allocated mutex lock LOCK for further use. */
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extern void __mutex_init (void *__lock);
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/* Lock LOCK, blocking if we can't get it. */
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extern void __mutex_lock_solid (void *__lock);
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/* Finish unlocking LOCK, after the spin lock LOCK->held has already been
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unlocked. This function will wake up any thread waiting on LOCK. */
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extern void __mutex_unlock_solid (void *__lock);
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/* Lock the mutex lock LOCK. */
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_EXTERN_INLINE void
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__mutex_lock (void *__lock)
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{
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if (! __spin_try_lock ((__spin_lock_t *) __lock))
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__mutex_lock_solid (__lock);
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}
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/* Unlock the mutex lock LOCK. */
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_EXTERN_INLINE void
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__mutex_unlock (void *__lock)
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{
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__spin_unlock ((__spin_lock_t *) __lock);
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__mutex_unlock_solid (__lock);
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}
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_EXTERN_INLINE int
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__mutex_trylock (void *__lock)
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{
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return __spin_try_lock ((__spin_lock_t *) __lock);
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}
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#endif /* lock-intern.h */
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