haiku/headers/private/libroot/libroot_lock.h

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