usr/src/cmd/svc/startd/dict.c

   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
  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
  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
  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
 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 }