xref: /onnv-gate/usr/src/uts/common/os/refstr.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate #include <sys/systm.h>
30*0Sstevel@tonic-gate #include <sys/param.h>
31*0Sstevel@tonic-gate #include <sys/atomic.h>
32*0Sstevel@tonic-gate #include <sys/kmem.h>
33*0Sstevel@tonic-gate #include <sys/refstr.h>
34*0Sstevel@tonic-gate #include <sys/refstr_impl.h>
35*0Sstevel@tonic-gate 
36*0Sstevel@tonic-gate refstr_t *
refstr_alloc(const char * str)37*0Sstevel@tonic-gate refstr_alloc(const char *str)
38*0Sstevel@tonic-gate {
39*0Sstevel@tonic-gate 	refstr_t *rsp;
40*0Sstevel@tonic-gate 	size_t size = sizeof (rsp->rs_size) + sizeof (rsp->rs_refcnt) +
41*0Sstevel@tonic-gate 		strlen(str) + 1;
42*0Sstevel@tonic-gate 
43*0Sstevel@tonic-gate 	ASSERT(size <= UINT32_MAX);
44*0Sstevel@tonic-gate 	rsp = kmem_alloc(size, KM_SLEEP);
45*0Sstevel@tonic-gate 	rsp->rs_size = (uint32_t)size;
46*0Sstevel@tonic-gate 	rsp->rs_refcnt = 1;
47*0Sstevel@tonic-gate 	(void) strcpy(rsp->rs_string, str);
48*0Sstevel@tonic-gate 	return (rsp);
49*0Sstevel@tonic-gate }
50*0Sstevel@tonic-gate 
51*0Sstevel@tonic-gate const char *
refstr_value(refstr_t * rsp)52*0Sstevel@tonic-gate refstr_value(refstr_t *rsp)
53*0Sstevel@tonic-gate {
54*0Sstevel@tonic-gate 	return (rsp != NULL ? (const char *)rsp->rs_string : NULL);
55*0Sstevel@tonic-gate }
56*0Sstevel@tonic-gate 
57*0Sstevel@tonic-gate void
refstr_hold(refstr_t * rsp)58*0Sstevel@tonic-gate refstr_hold(refstr_t *rsp)
59*0Sstevel@tonic-gate {
60*0Sstevel@tonic-gate 	atomic_add_32(&rsp->rs_refcnt, 1);
61*0Sstevel@tonic-gate }
62*0Sstevel@tonic-gate 
63*0Sstevel@tonic-gate void
refstr_rele(refstr_t * rsp)64*0Sstevel@tonic-gate refstr_rele(refstr_t *rsp)
65*0Sstevel@tonic-gate {
66*0Sstevel@tonic-gate 	if (atomic_add_32_nv(&rsp->rs_refcnt, -1) == 0)
67*0Sstevel@tonic-gate 		kmem_free(rsp, (size_t)rsp->rs_size);
68*0Sstevel@tonic-gate }
69