ceph/src/spdk/lib/event/subsystem.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright (c) Intel Corporation.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include "spdk_internal/event.h"
  35
  36 #include <stddef.h>
  37 #include <stdbool.h>
  38 #include <string.h>
  39
  40 static TAILQ_HEAD(spdk_subsystem_list, spdk_subsystem) g_subsystems =
  41         TAILQ_HEAD_INITIALIZER(g_subsystems);
  42 static TAILQ_HEAD(subsystem_depend, spdk_subsystem_depend) g_depends =
  43         TAILQ_HEAD_INITIALIZER(g_depends);
  44
  45 void
  46 spdk_add_subsystem(struct spdk_subsystem *subsystem)
  47 {
  48         TAILQ_INSERT_TAIL(&g_subsystems, subsystem, tailq);
  49 }
  50
  51 void
  52 spdk_add_subsystem_depend(struct spdk_subsystem_depend *depend)
  53 {
  54         TAILQ_INSERT_TAIL(&g_depends, depend, tailq);
  55 }
  56
  57 static struct spdk_subsystem *
  58 spdk_subsystem_find(struct spdk_subsystem_list *list, const char *name)
  59 {
  60         struct spdk_subsystem *iter;
  61
  62         TAILQ_FOREACH(iter, list, tailq) {
  63                 if (strcmp(name, iter->name) == 0) {
  64                         return iter;
  65                 }
  66         }
  67
  68         return NULL;
  69 }
  70
  71 static void
  72 subsystem_sort(void)
  73 {
  74         bool depends_on, depends_on_sorted;
  75         struct spdk_subsystem *subsystem, *subsystem_tmp;
  76         struct spdk_subsystem_depend *subsystem_dep;
  77
  78         struct spdk_subsystem_list subsystems_list = TAILQ_HEAD_INITIALIZER(subsystems_list);
  79
  80         while (!TAILQ_EMPTY(&g_subsystems)) {
  81                 TAILQ_FOREACH_SAFE(subsystem, &g_subsystems, tailq, subsystem_tmp) {
  82                         depends_on = false;
  83                         TAILQ_FOREACH(subsystem_dep, &g_depends, tailq) {
  84                                 if (strcmp(subsystem->name, subsystem_dep->name) == 0) {
  85                                         depends_on = true;
  86                                         depends_on_sorted = !!spdk_subsystem_find(&subsystems_list, subsystem_dep->depends_on);
  87                                         if (depends_on_sorted)
  88                                                 continue;
  89                                         break;
  90                                 }
  91                         }
  92
  93                         if (depends_on == false) {
  94                                 TAILQ_REMOVE(&g_subsystems, subsystem, tailq);
  95                                 TAILQ_INSERT_TAIL(&subsystems_list, subsystem, tailq);
  96                         } else {
  97                                 if (depends_on_sorted == true) {
  98                                         TAILQ_REMOVE(&g_subsystems, subsystem, tailq);
  99                                         TAILQ_INSERT_TAIL(&subsystems_list, subsystem, tailq);
 100                                 }
 101                         }
 102                 }
 103         }
 104
 105         TAILQ_FOREACH_SAFE(subsystem, &subsystems_list, tailq, subsystem_tmp) {
 106                 TAILQ_REMOVE(&subsystems_list, subsystem, tailq);
 107                 TAILQ_INSERT_TAIL(&g_subsystems, subsystem, tailq);
 108         }
 109 }
 110
 111 int
 112 spdk_subsystem_init(void)
 113 {
 114         int rc = 0;
 115         struct spdk_subsystem *subsystem;
 116         struct spdk_subsystem_depend *dep;
 117
 118         /* Verify that all dependency name and depends_on subsystems are registered */
 119         TAILQ_FOREACH(dep, &g_depends, tailq) {
 120                 if (!spdk_subsystem_find(&g_subsystems, dep->name)) {
 121                         fprintf(stderr, "subsystem %s is missing\n", dep->name);
 122                         return -1;
 123                 }
 124                 if (!spdk_subsystem_find(&g_subsystems, dep->depends_on)) {
 125                         fprintf(stderr, "subsystem %s dependency %s is missing\n",
 126                                 dep->name, dep->depends_on);
 127                         return -1;
 128                 }
 129         }
 130
 131         subsystem_sort();
 132
 133         TAILQ_FOREACH(subsystem, &g_subsystems, tailq) {
 134                 if (subsystem->init) {
 135                         rc = subsystem->init();
 136                         if (rc)
 137                                 return rc;
 138                 }
 139         }
 140         return rc;
 141 }
 142
 143 int
 144 spdk_subsystem_fini(void)
 145 {
 146         int rc = 0;
 147         struct spdk_subsystem *cur;
 148
 149         cur = TAILQ_LAST(&g_subsystems, spdk_subsystem_list);
 150
 151         while (cur) {
 152                 if (cur->fini) {
 153                         rc = cur->fini();
 154                         if (rc)
 155                                 return rc;
 156                 }
 157                 cur = TAILQ_PREV(cur, spdk_subsystem_list, tailq);
 158         }
 159
 160         return rc;
 161 }
 162
 163 void
 164 spdk_subsystem_config(FILE *fp)
 165 {
 166         struct spdk_subsystem *subsystem;
 167
 168         TAILQ_FOREACH(subsystem, &g_subsystems, tailq) {
 169                 if (subsystem->config)
 170                         subsystem->config(fp);
 171         }
 172 }