91 lines
1.6 KiB
C++
91 lines
1.6 KiB
C++
/*
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* Copyright 2002-2008, Axel Dörfler, axeld@pinc-software.de.
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* Distributed under the terms of the MIT License.
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*
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* Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
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* Distributed under the terms of the NewOS License.
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*/
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#ifndef _LIBROOT_LOCK_H
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#define _LIBROOT_LOCK_H
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#include <OS.h>
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// TODO: Copied from the kernel private lock.h/lock.c. We should somehow make
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// that code reusable.
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namespace BPrivate {
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typedef struct benaphore {
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sem_id sem;
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int32 count;
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} benaphore;
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static inline status_t
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benaphore_init(benaphore *ben, const char *name)
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{
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if (ben == NULL || name == NULL)
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return B_BAD_VALUE;
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ben->count = 1;
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ben->sem = create_sem(0, name);
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if (ben->sem >= B_OK)
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return B_OK;
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return ben->sem;
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}
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static inline status_t
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benaphore_lock_etc(benaphore *ben, uint32 flags, bigtime_t timeout)
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{
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// TODO: This function really shouldn't be used, since timeouts screw the
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// benaphore behavior.
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if (atomic_add(&ben->count, -1) <= 0)
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return acquire_sem_etc(ben->sem, 1, flags, timeout);
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return B_OK;
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}
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static inline status_t
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benaphore_lock(benaphore *ben)
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{
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if (atomic_add(&ben->count, -1) <= 0) {
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status_t error;
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do {
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error = acquire_sem(ben->sem);
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} while (error == B_INTERRUPTED);
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return error;
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}
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return B_OK;
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}
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static inline status_t
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benaphore_unlock(benaphore *ben)
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{
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if (atomic_add(&ben->count, 1) < 0)
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return release_sem(ben->sem);
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return B_OK;
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}
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} // namespace BPrivate
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using BPrivate::benaphore;
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using BPrivate::benaphore_init;
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using BPrivate::benaphore_lock_etc;
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using BPrivate::benaphore_lock;
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using BPrivate::benaphore_unlock;
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#endif // _LIBROOT_LOCK_H
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