xref: /illumos-gate/usr/src/cmd/svc/startd/dict.c (revision f37b3cbb6f67aaea5eec1c335bdc7bf432867d64)
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 /*
28  * dict.c - simple dictionary facility
29  *
30  * We maintain a dictionary, sorted by name to facilitate rapid id lookup by
31  * name. It is used by both the restarter and graph code.
32  *
33  * Right now, the dictionary is implemented as a sorted linked list which maps
34  * instance names to graph vertex ids.  It should eventually be converted to a
35  * better representation for quick lookups.
36  *
37  * For now, FMRIs are never deleted from the dictionary. A service deletion
38  * and insertion of the same instance FMRI will result in reuse of the same
39  * id. To implement dictionary entry delete, the locking strategy for graph
40  * vertex dependency linking must be checked for accuracy, as assumptions may
41  * exist that FMRI to id mapping is retained even after an instance is deleted.
42  */
43 
44 #include <sys/time.h>
45 
46 #include <assert.h>
47 #include <libuutil.h>
48 #include <string.h>
49 
50 #include "startd.h"
51 
52 static uu_list_pool_t *dict_pool;
53 dictionary_t *dictionary;
54 
55 static u_longlong_t dictionary_lookups;		/* number of lookups */
56 static u_longlong_t dictionary_ns_total;	/* nanoseconds spent */
57 
58 /*ARGSUSED*/
59 static int
60 dict_compare(const void *lc_arg, const void *rc_arg, void *private)
61 {
62 	const char *lc_name = ((const dict_entry_t *)lc_arg)->de_name;
63 	const char *rc_name = ((const dict_entry_t *)rc_arg)->de_name;
64 
65 	return (strcmp(lc_name, rc_name));
66 }
67 
68 int
69 dict_lookup_byname(const char *name)
70 {
71 	int id;
72 	dict_entry_t *entry, tmp;
73 	hrtime_t now = gethrtime();
74 
75 	tmp.de_name = name;
76 
77 	(void) pthread_mutex_lock(&dictionary->dict_lock);
78 	if ((entry = uu_list_find(dictionary->dict_list, &tmp, NULL,
79 	    NULL)) == NULL)
80 		id = -1;
81 	else
82 		id = entry->de_id;
83 
84 	(void) pthread_mutex_unlock(&dictionary->dict_lock);
85 
86 	dictionary_lookups++;
87 	dictionary_ns_total += gethrtime() - now;
88 
89 	return (id);
90 }
91 
92 /*
93  * int dict_insert(char *)
94  *   Returns the ID for name.
95  */
96 int
97 dict_insert(const char *name)
98 {
99 	dict_entry_t *entry, tmp;
100 	uu_list_index_t idx;
101 
102 	assert(name != NULL);
103 
104 	tmp.de_name = name;
105 
106 	(void) pthread_mutex_lock(&dictionary->dict_lock);
107 
108 	if ((entry = uu_list_find(dictionary->dict_list, &tmp, NULL,
109 	    &idx)) != NULL) {
110 		(void) pthread_mutex_unlock(&dictionary->dict_lock);
111 		return (entry->de_id);
112 	}
113 
114 	entry = startd_alloc(sizeof (dict_entry_t));
115 
116 	entry->de_id = dictionary->dict_new_id++;
117 	entry->de_name = startd_alloc(strlen(name) + 1);
118 	(void) strcpy((char *)entry->de_name, name);
119 
120 	uu_list_node_init(entry, &entry->de_link, dict_pool);
121 
122 	uu_list_insert(dictionary->dict_list, entry, idx);
123 	(void) pthread_mutex_unlock(&dictionary->dict_lock);
124 
125 	return (entry->de_id);
126 }
127 
128 void
129 dict_init()
130 {
131 	dictionary = startd_zalloc(sizeof (dictionary_t));
132 
133 	(void) pthread_mutex_init(&dictionary->dict_lock, NULL);
134 
135 	dict_pool = startd_list_pool_create("dict", sizeof (dict_entry_t),
136 	    offsetof(dict_entry_t, de_link), dict_compare, UU_LIST_POOL_DEBUG);
137 	assert(dict_pool != NULL);
138 
139 	dictionary->dict_new_id = 0;
140 	dictionary->dict_list = startd_list_create(dict_pool, dictionary,
141 	    UU_LIST_SORTED);
142 	assert(dictionary->dict_list != NULL);
143 }
144