numam-spdk/lib/notify/notify.c
Piotr Pelplinski de5f53220c notify: add notification library
This patch adds library that will provide ability to notify about
events. On one side each spdk library can specify what kind of
notification it can produce and on the other side libraries can fetch
those notifications.

Example is bdev module, which lib notify about added or removed bdev.

Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Signed-off-by: Piotr Pelplinski <piotr.pelplinski@intel.com>
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Change-Id: Ia95e564a8a43400b2745d9de8217b9cc84cd1b16
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/431920
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2019-03-29 21:15:14 +00:00

151 lines
4.3 KiB
C

/*-
* BSD LICENSE
*
* Copyright (c) Intel Corporation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/queue.h>
#include "spdk/stdinc.h"
#include "spdk/util.h"
#include "spdk/queue.h"
#include "spdk/string.h"
#include "spdk/log.h"
#include "spdk/notify.h"
#define SPDK_NOTIFY_MAX_EVENTS 1024
struct spdk_notify_type {
char name[SPDK_NOTIFY_MAX_NAME_SIZE];
TAILQ_ENTRY(spdk_notify_type) tailq;
};
pthread_mutex_t g_events_lock = PTHREAD_MUTEX_INITIALIZER;
static struct spdk_notify_event g_events[SPDK_NOTIFY_MAX_EVENTS];
static uint64_t g_events_head;
static TAILQ_HEAD(, spdk_notify_type) g_notify_types = TAILQ_HEAD_INITIALIZER(g_notify_types);
struct spdk_notify_type *
spdk_notify_type_register(const char *type)
{
struct spdk_notify_type *it = NULL;
if (!type) {
SPDK_ERRLOG("Invalid notification type %p\n", type);
return NULL;
} else if (!type || strlen(type) >= SPDK_NOTIFY_MAX_NAME_SIZE) {
SPDK_ERRLOG("Invalid notification type (add: %p, name: %s)\n", type,
type ? type : "(null)");
return NULL;
}
pthread_mutex_lock(&g_events_lock);
TAILQ_FOREACH(it, &g_notify_types, tailq) {
if (strcmp(type, it->name) == 0) {
SPDK_ERRLOG("Notification type '%s' already registered.\n", type);
goto out;
}
}
it = calloc(1, sizeof(*it));
if (it == NULL) {
goto out;
}
snprintf(it->name, sizeof(it->name), "%s", type);
TAILQ_INSERT_TAIL(&g_notify_types, it, tailq);
out:
pthread_mutex_unlock(&g_events_lock);
return it;
}
const char *
spdk_notify_type_get_name(const struct spdk_notify_type *type)
{
return type->name;
}
void
spdk_notify_get_types(spdk_notify_get_type_cb cb, void *ctx)
{
struct spdk_notify_type *it;
pthread_mutex_lock(&g_events_lock);
TAILQ_FOREACH(it, &g_notify_types, tailq) {
if (cb(it, ctx)) {
break;
}
}
pthread_mutex_unlock(&g_events_lock);
}
uint64_t
spdk_notify_send(const char *type, const char *ctx)
{
uint64_t head;
struct spdk_notify_event *ev;
pthread_mutex_lock(&g_events_lock);
head = g_events_head;
g_events_head++;
ev = &g_events[head % SPDK_NOTIFY_MAX_EVENTS];
spdk_strcpy_pad(ev->type, type, sizeof(ev->type), '\0');
spdk_strcpy_pad(ev->ctx, ctx, sizeof(ev->ctx), '\0');
pthread_mutex_unlock(&g_events_lock);
return head;
}
uint64_t
spdk_notify_get_events(uint64_t start_idx, uint64_t max, spdk_notify_get_event_cb cb_fn, void *ctx)
{
uint64_t i;
pthread_mutex_lock(&g_events_lock);
if (g_events_head > SPDK_NOTIFY_MAX_EVENTS && start_idx < g_events_head - SPDK_NOTIFY_MAX_EVENTS) {
start_idx = g_events_head - SPDK_NOTIFY_MAX_EVENTS;
}
for (i = 0; start_idx < g_events_head && i < max; start_idx++, i++) {
if (cb_fn(start_idx, &g_events[start_idx % SPDK_NOTIFY_MAX_EVENTS], ctx)) {
break;
}
}
pthread_mutex_unlock(&g_events_lock);
return i;
}