/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * routines to wait and wake up a client waiting on a list for a
 * name service request
 */
#include "cache.h"

int
nscd_wait(nsc_ctx_t *ctx, nsc_db_t *nscdb, nsc_entry_t *entry)
{
        waiter_t        mywait;
        waiter_t        *wchan = &nscdb->db_wait;

        (void) cond_init(&(mywait.w_waitcv), USYNC_THREAD, 0);
        mywait.w_key = entry;
        mywait.w_signaled = 0;
        mywait.w_next = wchan->w_next;
        mywait.w_prev = wchan;
        if (mywait.w_next)
                mywait.w_next->w_prev = &mywait;
        wchan->w_next = &mywait;

        (void) mutex_lock(&ctx->stats_mutex);
        ctx->stats.wait_count++;
        (void) mutex_unlock(&ctx->stats_mutex);

        while (!mywait.w_signaled)
                (void) cond_wait(&(mywait.w_waitcv), &nscdb->db_mutex);
        if (mywait.w_prev)
                mywait.w_prev->w_next = mywait.w_next;
        if (mywait.w_next)
                mywait.w_next->w_prev = mywait.w_prev;
        return (0);
}

int
nscd_signal(nsc_ctx_t *ctx, nsc_db_t *nscdb, nsc_entry_t *entry)
{
        int             c = 0;
        waiter_t        *wchan = &nscdb->db_wait;
        waiter_t        *tmp = wchan->w_next;

        while (tmp) {
                if (tmp->w_key == entry) {
                        (void) cond_signal(&(tmp->w_waitcv));
                        tmp->w_signaled = 1;

                        (void) mutex_lock(&ctx->stats_mutex);
                        ctx->stats.wait_count--;
                        (void) mutex_unlock(&ctx->stats_mutex);
                        c++;
                }
                tmp = tmp->w_next;
        }

        return (c);
}