zfs-builds-mm/zfs-0.8.1/include/sys/unique.h

58 lines
1.6 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_UNIQUE_H
#define _SYS_UNIQUE_H
#include <sys/zfs_context.h>
#ifdef __cplusplus
extern "C" {
#endif
/* The number of significant bits in each unique value. */
#define UNIQUE_BITS 56
void unique_init(void);
void unique_fini(void);
/*
* Return a new unique value (which will not be uniquified against until
* it is unique_insert()-ed).
*/
uint64_t unique_create(void);
/* Return a unique value, which equals the one passed in if possible. */
uint64_t unique_insert(uint64_t value);
/* Indicate that this value no longer needs to be uniquified against. */
void unique_remove(uint64_t value);
#ifdef __cplusplus
}
#endif
#endif /* _SYS_UNIQUE_H */