isns/isnsd/msgq.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <synch.h>

#include "isns_server.h"
#include "isns_msgq.h"
#include "isns_cache.h"
#include "isns_obj.h"
#include "isns_log.h"

msg_queue_t *
queue_calloc(
)
{
    msg_queue_t *q;

    q = (msg_queue_t *)calloc(1, sizeof (msg_queue_t));

    if (q) {
        if (sema_init(&q->q_sema, 0, USYNC_THREAD, NULL) ||
            pthread_mutex_init(&q->q_mutex, NULL)) {
            free(q);
            q = NULL;
        }
    }

    return (q);
}

int
queue_msg_set(
    msg_queue_t *q,
    msg_id_t id,
    void *data
)
{
    msg_text_t *msg;

    msg = (msg_text_t *)calloc(1, sizeof (msg_text_t));

    if (!msg) {
        return (1);
    }

    msg->id = id;
    msg->data = data;

    (void) pthread_mutex_lock(&q->q_mutex);

    if (q->q_head == NULL) {
        ASSERT(!q->q_tail);
        q->q_head = msg;
        q->q_tail = msg;
    } else {
        ASSERT(q->q_tail);
        q->q_tail->next = msg;
        msg->prev = q->q_tail;
        q->q_tail = msg;
    }

    (void) pthread_mutex_unlock(&q->q_mutex);

    (void) sema_post(&q->q_sema);

    return (0);
}

msg_text_t *
queue_msg_get(
    msg_queue_t *q
)
{
    msg_text_t *msg;

    while (sema_wait(&q->q_sema)) {
        (void) sleep(1);
    }

    (void) pthread_mutex_lock(&q->q_mutex);

    msg = q->q_head;
    ASSERT(msg);
    q->q_head = msg->next;
    if (q->q_head == NULL) {
        q->q_tail = NULL;
    }

    (void) pthread_mutex_unlock(&q->q_mutex);

    return (msg);
}

void
queue_msg_free(
    msg_text_t *msg
)
{
    free(msg);
}