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 <pthread.h>
49#include <sys/mman.h>
50
51#include "libmicro.h"
52
53typedef struct {
54	int			ts_once;
55	int			ts_id;
56	int			ts_us0;		/* our lock indices */
57	int			ts_us1;
58	int			ts_them0;	/* their lock indices */
59	int			ts_them1;
60} tsd_t;
61
62static int			nthreads;
63
64/*
65 * API-specific code BEGINS here
66 */
67
68static int			opts = 0;
69static int			nlocks;
70static pthread_mutex_t	*locks;
71
72int
73benchmark_init()
74{
75	lm_tsdsize = sizeof (tsd_t);
76
77	(void) sprintf(lm_optstr, "s");
78
79	lm_defN = "cscd_mutex";
80
81	(void) sprintf(lm_usage,
82	    "       [-s] (force PTHREAD_PROCESS_SHARED)\n"
83	    "notes: thread cascade using pthread_mutexes\n");
84
85	return (0);
86}
87
88/*ARGSUSED*/
89int
90benchmark_optswitch(int opt, char *optarg)
91{
92	switch (opt) {
93	case 's':
94		opts = 1;
95		break;
96	default:
97		return (-1);
98	}
99	return (0);
100}
101
102int
103benchmark_initrun()
104{
105	int			i;
106	int			e = 0;
107	pthread_mutexattr_t	ma;
108
109	nthreads = lm_optP * lm_optT;
110	nlocks = nthreads * 2;
111	/*LINTED*/
112	locks = (pthread_mutex_t *)mmap(NULL,
113	    nlocks * sizeof (pthread_mutex_t),
114	    PROT_READ | PROT_WRITE,
115	    MAP_ANON | MAP_SHARED,
116	    -1, 0L);
117	if (locks == MAP_FAILED) {
118		return (1);
119	}
120
121	(void) pthread_mutexattr_init(&ma);
122	if (lm_optP > 1 || opts) {
123		(void) pthread_mutexattr_setpshared(&ma,
124		    PTHREAD_PROCESS_SHARED);
125	} else {
126		(void) pthread_mutexattr_setpshared(&ma,
127		    PTHREAD_PROCESS_PRIVATE);
128	}
129
130	for (i = 0; i < nlocks; i++) {
131		(void) pthread_mutex_init(&locks[i], &ma);
132	}
133
134	return (e);
135}
136
137int
138block(int index)
139{
140	return (pthread_mutex_lock(&locks[index]) == -1);
141}
142
143int
144unblock(int index)
145{
146	return (pthread_mutex_unlock(&locks[index]) == -1);
147}
148
149/*
150 * API-specific code ENDS here
151 */
152
153int
154benchmark_initbatch(void *tsd)
155{
156	tsd_t			*ts = (tsd_t *)tsd;
157	int			e = 0;
158
159	if (ts->ts_once == 0) {
160		int		us, them;
161
162#if !defined(__APPLE__)
163                us = (getpindex() * lm_optT) + gettindex();
164#else
165                us = gettsdindex(tsd);
166#endif /* __APPLE__ */
167
168		them = (us + 1) % (lm_optP * lm_optT);
169
170		ts->ts_id = us;
171
172		/* lock index asignment for us and them */
173		ts->ts_us0 = (us * 2);
174		ts->ts_us1 = (us * 2) + 1;
175		if (us < nthreads - 1) {
176			/* straight-thru connection to them */
177			ts->ts_them0 = (them * 2);
178			ts->ts_them1 = (them * 2) + 1;
179		} else {
180			/* cross-over connection to them */
181			ts->ts_them0 = (them * 2) + 1;
182			ts->ts_them1 = (them * 2);
183		}
184
185		ts->ts_once = 1;
186	}
187
188	/* block their first move */
189	e += block(ts->ts_them0);
190
191	return (e);
192}
193
194int
195benchmark(void *tsd, result_t *res)
196{
197	tsd_t			*ts = (tsd_t *)tsd;
198	int			i;
199	int			e = 0;
200
201	/* wait to be unblocked (id == 0 will not block) */
202	e += block(ts->ts_us0);
203
204	for (i = 0; i < lm_optB; i += 2) {
205		/* allow them to block us again */
206		e += unblock(ts->ts_us0);
207
208		/* block their next + 1 move */
209		e += block(ts->ts_them1);
210
211		/* unblock their next move */
212		e += unblock(ts->ts_them0);
213
214		/* wait for them to unblock us */
215		e += block(ts->ts_us1);
216
217		/* repeat with locks reversed */
218		e += unblock(ts->ts_us1);
219		e += block(ts->ts_them0);
220		e += unblock(ts->ts_them1);
221		e += block(ts->ts_us0);
222	}
223
224	/* finish batch with nothing blocked */
225	e += unblock(ts->ts_them0);
226	e += unblock(ts->ts_us0);
227
228	res->re_count = i;
229	res->re_errors = e;
230
231	return (0);
232}
233