85 lines
1.1 KiB
C++
85 lines
1.1 KiB
C++
/*
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* Copyright 2006, Haiku, Inc. All Rights Reserved.
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* Distributed under the terms of the MIT License.
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*
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* Authors:
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* Axel Dörfler, axeld@pinc-software.de
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*/
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#ifndef LOCK_H
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#define LOCK_H
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#include <OS.h>
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typedef struct lock {
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sem_id sem;
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vint32 count;
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} lock;
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static inline status_t
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init_lock(struct lock *lock, const char *name)
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{
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lock->sem = create_sem(0, name);
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lock->count = 0;
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return lock->sem < B_OK ? lock->sem : B_OK;
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}
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static inline void
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uninit_lock(struct lock *lock)
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{
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delete_sem(lock->sem);
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}
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static inline status_t
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acquire_lock(struct lock *lock)
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{
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if (atomic_add(&lock->count, 1) > 0)
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return acquire_sem(lock->sem);
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return B_OK;
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}
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static inline status_t
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release_lock(struct lock *lock)
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{
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if (atomic_add(&lock->count, -1) > 1)
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return release_sem(lock->sem);
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return B_OK;
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}
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class Autolock {
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public:
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Autolock(struct lock &lock)
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:
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fLock(&lock)
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{
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fStatus = acquire_lock(fLock);
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}
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~Autolock()
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{
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if (fStatus == B_OK)
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release_lock(fLock);
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}
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bool
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IsLocked() const
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{
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return fStatus == B_OK;
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}
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private:
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status_t fStatus;
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struct lock *fLock;
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};
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#endif /* LOCK_H */ |