xref: /titanic_41/usr/src/cmd/svc/startd/dict.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * dict.c - simple dictionary facility
31  *
32  * We maintain a dictionary, sorted by name to facilitate rapid id lookup by
33  * name. It is used by both the restarter and graph code.
34  *
35  * Right now, the dictionary is implemented as a sorted linked list which maps
36  * instance names to graph vertex ids.  It should eventually be converted to a
37  * better representation for quick lookups.
38  *
39  * For now, FMRIs are never deleted from the dictionary. A service deletion
40  * and insertion of the same instance FMRI will result in reuse of the same
41  * id. To implement dictionary entry delete, the locking strategy for graph
42  * vertex dependency linking must be checked for accuracy, as assumptions may
43  * exist that FMRI to id mapping is retained even after an instance is deleted.
44  */
45 
46 #include <sys/time.h>
47 
48 #include <assert.h>
49 #include <libuutil.h>
50 #include <string.h>
51 
52 #include "startd.h"
53 
54 static uu_list_pool_t *dict_pool;
55 dictionary_t *dictionary;
56 
57 static u_longlong_t dictionary_lookups;		/* number of lookups */
58 static u_longlong_t dictionary_ns_total;	/* nanoseconds spent */
59 
60 /*ARGSUSED*/
61 static int
dict_compare(const void * lc_arg,const void * rc_arg,void * private)62 dict_compare(const void *lc_arg, const void *rc_arg, void *private)
63 {
64 	const char *lc_name = ((const dict_entry_t *)lc_arg)->de_name;
65 	const char *rc_name = ((const dict_entry_t *)rc_arg)->de_name;
66 
67 	return (strcmp(lc_name, rc_name));
68 }
69 
70 int
dict_lookup_byname(const char * name)71 dict_lookup_byname(const char *name)
72 {
73 	int id;
74 	dict_entry_t *entry, tmp;
75 	hrtime_t now = gethrtime();
76 
77 	tmp.de_name = name;
78 
79 	(void) pthread_mutex_lock(&dictionary->dict_lock);
80 	if ((entry = uu_list_find(dictionary->dict_list, &tmp, NULL,
81 	    NULL)) == NULL)
82 		id = -1;
83 	else
84 		id = entry->de_id;
85 
86 	(void) pthread_mutex_unlock(&dictionary->dict_lock);
87 
88 	dictionary_lookups++;
89 	dictionary_ns_total += gethrtime() - now;
90 
91 	return (id);
92 }
93 
94 /*
95  * int dict_insert(char *)
96  *   Returns the ID for name.
97  */
98 int
dict_insert(const char * name)99 dict_insert(const char *name)
100 {
101 	dict_entry_t *entry, tmp;
102 	uu_list_index_t idx;
103 
104 	assert(name != NULL);
105 
106 	tmp.de_name = name;
107 
108 	(void) pthread_mutex_lock(&dictionary->dict_lock);
109 
110 	if ((entry = uu_list_find(dictionary->dict_list, &tmp, NULL,
111 	    &idx)) != NULL) {
112 		(void) pthread_mutex_unlock(&dictionary->dict_lock);
113 		return (entry->de_id);
114 	}
115 
116 	entry = startd_alloc(sizeof (dict_entry_t));
117 
118 	entry->de_id = dictionary->dict_new_id++;
119 	entry->de_name = startd_alloc(strlen(name) + 1);
120 	(void) strcpy((char *)entry->de_name, name);
121 
122 	uu_list_node_init(entry, &entry->de_link, dict_pool);
123 
124 	uu_list_insert(dictionary->dict_list, entry, idx);
125 	(void) pthread_mutex_unlock(&dictionary->dict_lock);
126 
127 	return (entry->de_id);
128 }
129 
130 void
dict_init()131 dict_init()
132 {
133 	dictionary = startd_zalloc(sizeof (dictionary_t));
134 
135 	(void) pthread_mutex_init(&dictionary->dict_lock, NULL);
136 
137 	dict_pool = startd_list_pool_create("dict", sizeof (dict_entry_t),
138 	    offsetof(dict_entry_t, de_link), dict_compare, UU_LIST_POOL_DEBUG);
139 	assert(dict_pool != NULL);
140 
141 	dictionary->dict_new_id = 0;
142 	dictionary->dict_list = startd_list_create(dict_pool, dictionary,
143 	    UU_LIST_SORTED);
144 	assert(dictionary->dict_list != NULL);
145 }
146