serializer_shutdown_group.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2012-2013, Digium, Inc.
 *
 * Mark Michelson <mmmichelson@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */
 
 
#include "asterisk.h"
 
#include "asterisk/serializer_shutdown_group.h"
#include "asterisk/astobj2.h"
#include "asterisk/time.h"
#include "asterisk/utils.h"
 
/*! Serializer group shutdown control object. */
struct ast_serializer_shutdown_group {
    /*! Shutdown thread waits on this conditional. */
    ast_cond_t cond;
    /*! Count of serializers needing to shutdown. */
    int count;
};
 
static void serializer_shutdown_group_dtor(void *vdoomed)
{
    struct ast_serializer_shutdown_group *doomed = vdoomed;
 
    ast_cond_destroy(&doomed->cond);
}
 
struct ast_serializer_shutdown_group *ast_serializer_shutdown_group_alloc(void)
{
    struct ast_serializer_shutdown_group *shutdown_group;
 
    shutdown_group = ao2_alloc(sizeof(*shutdown_group), serializer_shutdown_group_dtor);
    if (!shutdown_group) {
        return NULL;
    }
    ast_cond_init(&shutdown_group->cond, NULL);
    return shutdown_group;
}
 
int ast_serializer_shutdown_group_join(struct ast_serializer_shutdown_group *shutdown_group, int timeout)
{
    int remaining;
    ast_mutex_t *lock;
 
    if (!shutdown_group) {
        return 0;
    }
 
    lock = ao2_object_get_lockaddr(shutdown_group);
    ast_assert(lock != NULL);
 
    ao2_lock(shutdown_group);
    if (timeout) {
        struct timeval start;
        struct timespec end;
 
        start = ast_tvnow();
        end.tv_sec = start.tv_sec + timeout;
        end.tv_nsec = start.tv_usec * 1000;
        while (shutdown_group->count) {
            if (ast_cond_timedwait(&shutdown_group->cond, lock, &end)) {
                /* Error or timed out waiting for the count to reach zero. */
                break;
            }
        }
    } else {
        while (shutdown_group->count) {
            if (ast_cond_wait(&shutdown_group->cond, lock)) {
                /* Error */
                break;
            }
        }
    }
    remaining = shutdown_group->count;
    ao2_unlock(shutdown_group);
    return remaining;
}
 
void ast_serializer_shutdown_group_inc(struct ast_serializer_shutdown_group *shutdown_group)
{
    ao2_lock(shutdown_group);
    ++shutdown_group->count;
    ao2_unlock(shutdown_group);
}
 
void ast_serializer_shutdown_group_dec(struct ast_serializer_shutdown_group *shutdown_group)
{
    ao2_lock(shutdown_group);
    --shutdown_group->count;
    if (!shutdown_group->count) {
        ast_cond_signal(&shutdown_group->cond);
    }
    ao2_unlock(shutdown_group);
}