xref: /titanic_41/usr/src/cmd/nscd/nscd_wait.c (revision fcf3ce441efd61da9bb2884968af01cb7c1452cc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * routines to wait and wake up a client waiting on a list for a
30  * name service request
31  */
32 #include "cache.h"
33 
34 int
35 nscd_wait(nsc_ctx_t *ctx, nsc_db_t *nscdb, nsc_entry_t *entry)
36 {
37 	waiter_t	mywait;
38 	waiter_t	*wchan = &nscdb->db_wait;
39 
40 	(void) cond_init(&(mywait.w_waitcv), USYNC_THREAD, 0);
41 	mywait.w_key = entry;
42 	mywait.w_signaled = 0;
43 	mywait.w_next = wchan->w_next;
44 	mywait.w_prev = wchan;
45 	if (mywait.w_next)
46 		mywait.w_next->w_prev = &mywait;
47 	wchan->w_next = &mywait;
48 
49 	(void) mutex_lock(&ctx->stats_mutex);
50 	ctx->stats.wait_count++;
51 	(void) mutex_unlock(&ctx->stats_mutex);
52 
53 	while (!mywait.w_signaled)
54 		(void) cond_wait(&(mywait.w_waitcv), &nscdb->db_mutex);
55 	if (mywait.w_prev)
56 		mywait.w_prev->w_next = mywait.w_next;
57 	if (mywait.w_next)
58 		mywait.w_next->w_prev = mywait.w_prev;
59 	return (0);
60 }
61 
62 int
63 nscd_signal(nsc_ctx_t *ctx, nsc_db_t *nscdb, nsc_entry_t *entry)
64 {
65 	int		c = 0;
66 	waiter_t	*wchan = &nscdb->db_wait;
67 	waiter_t	*tmp = wchan->w_next;
68 
69 	while (tmp) {
70 		if (tmp->w_key == entry) {
71 			(void) cond_signal(&(tmp->w_waitcv));
72 			tmp->w_signaled = 1;
73 
74 			(void) mutex_lock(&ctx->stats_mutex);
75 			ctx->stats.wait_count--;
76 			(void) mutex_unlock(&ctx->stats_mutex);
77 			c++;
78 		}
79 		tmp = tmp->w_next;
80 	}
81 
82 	return (c);
83 }
84