1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms
5 * of the Common Development and Distribution License
6 * (the "License").  You may not use this file except
7 * in compliance with the License.
8 *
9 * You can obtain a copy of the license at
10 * src/OPENSOLARIS.LICENSE
11 * or http://www.opensolaris.org/os/licensing.
12 * See the License for the specific language governing
13 * permissions and limitations under the License.
14 *
15 * When distributing Covered Code, include this CDDL
16 * HEADER in each file and include the License file at
17 * usr/src/OPENSOLARIS.LICENSE.  If applicable,
18 * add the following below this CDDL HEADER, with the
19 * fields enclosed by brackets "[]" replaced with your
20 * own identifying information: Portions Copyright [yyyy]
21 * [name of copyright owner]
22 *
23 * CDDL HEADER END
24 */
25
26/*
27 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
28 * Use is subject to license terms.
29 */
30
31/*
32 * The "cascade" test case is a multiprocess/multithread batten-passing model
33 * using lock primitives alone for synchronisation. Threads are arranged in a
34 * ring. Each thread has two locks of its own on which it blocks, and is able
35 * to manipulate the two locks belonging to the thread which follows it in the
36 * ring.
37 *
38 * The number of threads (nthreads) is specified by the generic libMicro -P/-T
39 * options. With nthreads == 1 (the default) the uncontended case can be timed.
40 *
41 * The main logic is generic and allows any simple blocking API to be tested.
42 * The API-specific component is clearly indicated.
43 */
44
45#include <unistd.h>
46#include <stdlib.h>
47#include <stdio.h>
48#include <fcntl.h>
49#include <sys/file.h>
50
51#include "libmicro.h"
52
53#ifndef LOCK_EX
54#include "/usr/ucbinclude/sys/file.h"
55extern int flock(int fd, int operation);
56#endif
57
58typedef struct {
59	int			ts_once;
60	int			ts_id;
61	int			ts_us0;		/* our lock indices */
62	int			ts_us1;
63	int			ts_them0;	/* their lock indices */
64	int			ts_them1;
65} tsd_t;
66
67static int			nthreads;
68
69/*
70 * API-specific code BEGINS here
71 */
72
73#define	DEFD			"/tmp"
74
75static char			*optd = DEFD;
76static int			nfiles;
77static int			*files;
78
79int
80benchmark_init()
81{
82	lm_tsdsize = sizeof (tsd_t);
83
84	(void) sprintf(lm_optstr, "d:");
85
86	lm_defN = "cscd_flock";
87
88	(void) sprintf(lm_usage,
89	    "       [-d directory for temp files (default %s)]\n"
90	    "notes: thread cascade using flock file locking\n",
91	    DEFD);
92
93	return (0);
94}
95
96int
97benchmark_optswitch(int opt, char *optarg)
98{
99	switch (opt) {
100	case 'd':
101		optd = optarg;
102		break;
103	default:
104		return (-1);
105	}
106	return (0);
107}
108
109int
110benchmark_initrun()
111{
112	int			i;
113	int			errors = 0;
114	char			fname[1024];
115
116	nthreads = lm_optP * lm_optT;
117	nfiles = nthreads * 2;
118	(void) setfdlimit(nfiles + 10);
119	files = (int *)malloc(nfiles * sizeof (int));
120	if (files == NULL) {
121		return (1);
122	}
123
124	(void) sprintf(fname, "%s/cascade.%ld", optd, getpid());
125
126	for (i = 0; i < nfiles; i++) {
127		files[i] = open(fname, O_CREAT | O_TRUNC | O_RDWR, 0600);
128		if (files[i] == -1) {
129			errors++;
130		}
131		if (unlink(fname)) {
132			errors++;
133		}
134	}
135
136	return (errors);
137}
138
139int
140block(int index)
141{
142	return (flock(files[index], LOCK_EX) == -1);
143}
144
145int
146unblock(int index)
147{
148	return (flock(files[index], LOCK_UN) == -1);
149}
150
151/*
152 * API-specific code ENDS here
153 */
154
155int
156benchmark_initbatch(void *tsd)
157{
158	tsd_t			*ts = (tsd_t *)tsd;
159	int			e = 0;
160
161	if (ts->ts_once == 0) {
162		int		us, them;
163
164		us = (getpindex() * lm_optT) + gettindex();
165		them = (us + 1) % (lm_optP * lm_optT);
166
167		ts->ts_id = us;
168
169		/* lock index asignment for us and them */
170		ts->ts_us0 = (us * 2);
171		ts->ts_us1 = (us * 2) + 1;
172		if (us < nthreads - 1) {
173			/* straight-thru connection to them */
174			ts->ts_them0 = (them * 2);
175			ts->ts_them1 = (them * 2) + 1;
176		} else {
177			/* cross-over connection to them */
178			ts->ts_them0 = (them * 2) + 1;
179			ts->ts_them1 = (them * 2);
180		}
181
182		ts->ts_once = 1;
183	}
184
185	/* block their first move */
186	e += block(ts->ts_them0);
187
188	return (e);
189}
190
191int
192benchmark(void *tsd, result_t *res)
193{
194	tsd_t			*ts = (tsd_t *)tsd;
195	int			i;
196	int			e = 0;
197
198	/* wait to be unblocked (id == 0 will not block) */
199	e += block(ts->ts_us0);
200
201	for (i = 0; i < lm_optB; i += 2) {
202		/* allow them to block us again */
203		e += unblock(ts->ts_us0);
204
205		/* block their next + 1 move */
206		e += block(ts->ts_them1);
207
208		/* unblock their next move */
209		e += unblock(ts->ts_them0);
210
211		/* wait for them to unblock us */
212		e += block(ts->ts_us1);
213
214		/* repeat with locks reversed */
215		e += unblock(ts->ts_us1);
216		e += block(ts->ts_them0);
217		e += unblock(ts->ts_them1);
218		e += block(ts->ts_us0);
219	}
220
221	/* finish batch with nothing blocked */
222	e += unblock(ts->ts_them0);
223	e += unblock(ts->ts_us0);
224
225	res->re_count = i;
226	res->re_errors = e;
227
228	return (0);
229}
230