ceph/src/spdk/lib/notify/notify.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 <sys/queue.h>
  35
  36 #include "spdk/stdinc.h"
  37 #include "spdk/util.h"
  38 #include "spdk/queue.h"
  39 #include "spdk/string.h"
  40 #include "spdk/log.h"
  41
  42 #include "spdk/notify.h"
  43
  44 #define SPDK_NOTIFY_MAX_EVENTS  1024
  45
  46 struct spdk_notify_type {
  47         char name[SPDK_NOTIFY_MAX_NAME_SIZE];
  48         TAILQ_ENTRY(spdk_notify_type) tailq;
  49 };
  50
  51 pthread_mutex_t g_events_lock = PTHREAD_MUTEX_INITIALIZER;
  52 static struct spdk_notify_event g_events[SPDK_NOTIFY_MAX_EVENTS];
  53 static uint64_t g_events_head;
  54
  55 static TAILQ_HEAD(, spdk_notify_type) g_notify_types = TAILQ_HEAD_INITIALIZER(g_notify_types);
  56
  57 struct spdk_notify_type *
  58 spdk_notify_type_register(const char *type)
  59 {
  60         struct spdk_notify_type *it = NULL;
  61
  62         if (!type) {
  63                 SPDK_ERRLOG("Invalid notification type %p\n", type);
  64                 return NULL;
  65         } else if (!type[0] || strlen(type) >= SPDK_NOTIFY_MAX_NAME_SIZE) {
  66                 SPDK_ERRLOG("Notification type '%s' too short or too long\n", type);
  67                 return NULL;
  68         }
  69
  70         pthread_mutex_lock(&g_events_lock);
  71         TAILQ_FOREACH(it, &g_notify_types, tailq) {
  72                 if (strcmp(type, it->name) == 0) {
  73                         SPDK_NOTICELOG("Notification type '%s' already registered.\n", type);
  74                         goto out;
  75                 }
  76         }
  77
  78         it = calloc(1, sizeof(*it));
  79         if (it == NULL) {
  80                 goto out;
  81         }
  82
  83         snprintf(it->name, sizeof(it->name), "%s", type);
  84         TAILQ_INSERT_TAIL(&g_notify_types, it, tailq);
  85
  86 out:
  87         pthread_mutex_unlock(&g_events_lock);
  88         return it;
  89 }
  90
  91 const char *
  92 spdk_notify_type_get_name(const struct spdk_notify_type *type)
  93 {
  94         return type->name;
  95 }
  96
  97
  98 void
  99 spdk_notify_foreach_type(spdk_notify_foreach_type_cb cb, void *ctx)
 100 {
 101         struct spdk_notify_type *it;
 102
 103         pthread_mutex_lock(&g_events_lock);
 104         TAILQ_FOREACH(it, &g_notify_types, tailq) {
 105                 if (cb(it, ctx)) {
 106                         break;
 107                 }
 108         }
 109         pthread_mutex_unlock(&g_events_lock);
 110 }
 111
 112 uint64_t
 113 spdk_notify_send(const char *type, const char *ctx)
 114 {
 115         uint64_t head;
 116         struct spdk_notify_event *ev;
 117
 118         pthread_mutex_lock(&g_events_lock);
 119         head = g_events_head;
 120         g_events_head++;
 121
 122         ev = &g_events[head % SPDK_NOTIFY_MAX_EVENTS];
 123         spdk_strcpy_pad(ev->type, type, sizeof(ev->type), '\0');
 124         spdk_strcpy_pad(ev->ctx, ctx, sizeof(ev->ctx), '\0');
 125         pthread_mutex_unlock(&g_events_lock);
 126
 127         return head;
 128 }
 129
 130 uint64_t
 131 spdk_notify_foreach_event(uint64_t start_idx, uint64_t max,
 132                           spdk_notify_foreach_event_cb cb_fn, void *ctx)
 133 {
 134         uint64_t i;
 135
 136         pthread_mutex_lock(&g_events_lock);
 137
 138         if (g_events_head > SPDK_NOTIFY_MAX_EVENTS && start_idx < g_events_head - SPDK_NOTIFY_MAX_EVENTS) {
 139                 start_idx = g_events_head - SPDK_NOTIFY_MAX_EVENTS;
 140         }
 141
 142         for (i = 0; start_idx < g_events_head && i < max; start_idx++, i++) {
 143                 if (cb_fn(start_idx, &g_events[start_idx % SPDK_NOTIFY_MAX_EVENTS], ctx)) {
 144                         break;
 145                 }
 146         }
 147         pthread_mutex_unlock(&g_events_lock);
 148
 149         return i;
 150 }