1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #ifndef _SYS_UNIQUE_H 27 #define _SYS_UNIQUE_H 28 29 #include <sys/zfs_context.h> 30 31 #ifdef __cplusplus 32 extern "C" { 33 #endif 34 35 /* The number of significant bits in each unique value. */ 36 #define UNIQUE_BITS 56 37 38 void unique_init(void); 39 void unique_fini(void); 40 41 /* 42 * Return a new unique value (which will not be uniquified against until 43 * it is unique_insert()-ed). 44 */ 45 uint64_t unique_create(void); 46 47 /* Return a unique value, which equals the one passed in if possible. */ 48 uint64_t unique_insert(uint64_t value); 49 50 /* Indicate that this value no longer needs to be uniquified against. */ 51 void unique_remove(uint64_t value); 52 53 #ifdef __cplusplus 54 } 55 #endif 56 57 #endif /* _SYS_UNIQUE_H */ 58