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 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /*
27  * Copyright (c) 2012 by Delphix. All rights reserved.
28  */
29 
30 /*
31  * ASSERTION:
32  *   Positive test for ring buffer policy.
33  *
34  * SECTION: Buffers and Buffering/ring Policy;
35  *	Buffers and Buffering/Buffer Sizes;
36  *	Options and Tunables/bufsize;
37  *	Options and Tunables/bufpolicy
38  */
39 
40 /*
41  * We make some regrettable assumptions about the implementation in this
42  * test.  First, we assume that each entry for the printf() of an int
43  * takes _exactly_ 16 bytes (4 bytes for the EPID, 8 bytes for the
44  * timestamp, 4 bytes for the payload).  Second, we assume that by
45  * allocating storage for n + 1 records, we will get exactly n.  Here is
46  * why:  the final predicate that evaluates to false will reserve space
47  * that it won't use.  This act of reservation will advance the wrapped
48  * offset.  That record won't be subsequently used, but the wrapped
49  * offset has advanced.  (And in this case, that old record is clobbered
50  * by the exit() anyway.)  Thirdly:  we rely on t_cpu/cpu_id.  Finally:
51  * we rely on being able to run on the CPU that we first ran on.
52  */
53 #pragma D option bufpolicy=ring
54 #pragma D option bufsize=80
55 #pragma D option quiet
56 
57 int n;
58 
59 BEGIN
60 {
61 	cpuid = -1;
62 }
63 
64 tick-10msec
65 /cpuid == -1/
66 {
67 	cpuid = curthread->t_cpu->cpu_id;
68 }
69 
70 tick-10msec
71 /curthread->t_cpu->cpu_id == cpuid && n < 100/
72 {
73 	printf("%d\n", n++);
74 }
75 
76 tick-10msec
77 /n == 100/
78 {
79 	exit(0);
80 }
81