1/******************************************************************************
2 *
3 *   Copyright © International Business Machines  Corp., 2005, 2008
4 *
5 *   This program is free software;  you can redistribute it and/or modify
6 *   it under the terms of the GNU General Public License as published by
7 *   the Free Software Foundation; either version 2 of the License, or
8 *   (at your option) any later version.
9 *
10 *   This program is distributed in the hope that it will be useful,
11 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13 *   the GNU General Public License for more details.
14 *
15 *   You should have received a copy of the GNU General Public License
16 *   along with this program;  if not, write to the Free Software
17 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * NAME
20 *      testpi-2.c
21 *
22 * DESCRIPTION
23 *      This testcase verifies if the low priority SCHED_RR thread can preempt
24 *      the high priority SCHED_RR thread multiple times via priority
25 *      inheritance.
26 *
27 * USAGE:
28 *      Use run_auto.sh script in current directory to build and run test.
29 *
30 * AUTHOR
31 *
32 *
33 * HISTORY
34 *      2010-04-22 Code cleanup and thread synchronization changes by using
35 *		 conditional variables,
36 *		 by Gowrishankar(gowrishankar.m@in.ibm.com).
37 *
38 *****************************************************************************/
39
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <sched.h>
44#include <pthread.h>
45#include <sys/types.h>
46#include <sys/syscall.h>
47#include <unistd.h>
48#include <librttest.h>
49
50pthread_barrier_t barrier;
51
52void usage(void)
53{
54	rt_help();
55	printf("testpi-2 specific options:\n");
56}
57
58int parse_args(int c, char *v)
59{
60
61	int handled = 1;
62	switch (c) {
63	case 'h':
64		usage();
65		exit(0);
66	default:
67		handled = 0;
68		break;
69	}
70	return handled;
71}
72
73int gettid(void)
74{
75	return syscall(__NR_gettid);
76}
77
78typedef void *(*entrypoint_t) (void *);
79pthread_mutex_t glob_mutex;
80static pthread_mutex_t cond_mutex = PTHREAD_MUTEX_INITIALIZER;
81static pthread_cond_t cond_var = PTHREAD_COND_INITIALIZER;
82
83void *func_lowrt(void *arg)
84{
85	struct thread *pthr = (struct thread *)arg;
86	int i, tid = gettid();
87
88	printf("Thread %d started running with priority %d\n", tid,
89	       pthr->priority);
90	pthread_mutex_lock(&glob_mutex);
91	printf("Thread %d at start pthread pol %d pri %d - Got global lock\n",
92	       tid, pthr->policy, pthr->priority);
93	/* Wait for other RT threads to start up */
94	pthread_barrier_wait(&barrier);
95
96	/* Wait for the high priority noise thread to start and signal us */
97	pthread_mutex_lock(&cond_mutex);
98	pthread_cond_wait(&cond_var, &cond_mutex);
99	pthread_mutex_unlock(&cond_mutex);
100
101	for (i = 0; i < 10000; i++) {
102		if (i % 100 == 0) {
103			printf("Thread %d loop %d pthread pol %d pri %d\n",
104			       tid, i, pthr->policy, pthr->priority);
105			fflush(NULL);
106		}
107		busy_work_ms(1);
108	}
109	pthread_mutex_unlock(&glob_mutex);
110	return NULL;
111}
112
113void *func_rt(void *arg)
114{
115	struct thread *pthr = (struct thread *)arg;
116	int i, tid = gettid();
117
118	printf("Thread %d started running with prio %d\n", tid, pthr->priority);
119	pthread_barrier_wait(&barrier);
120	pthread_mutex_lock(&glob_mutex);
121	printf("Thread %d at start pthread pol %d pri %d - Got global lock\n",
122	       tid, pthr->policy, pthr->priority);
123
124	/* We just use the mutex as something to slow things down,
125	 * say who we are and then do nothing for a while.  The aim
126	 * of this is to show that high priority threads make more
127	 * progress than lower priority threads..
128	 */
129	for (i = 0; i < 1000; i++) {
130		if (i % 100 == 0) {
131			printf("Thread %d loop %d pthread pol %d pri %d\n",
132			       tid, i, pthr->policy, pthr->priority);
133			fflush(NULL);
134		}
135		busy_work_ms(1);
136	}
137	pthread_mutex_unlock(&glob_mutex);
138	return NULL;
139}
140
141void *func_noise(void *arg)
142{
143	struct thread *pthr = (struct thread *)arg;
144	int i, tid = gettid();
145
146	printf("Noise Thread %d started running with prio %d\n", tid,
147	       pthr->priority);
148	pthread_barrier_wait(&barrier);
149
150	/* Let others wait at conditional variable */
151	usleep(1000);
152
153	/* Noise thread begins the test */
154	pthread_mutex_lock(&cond_mutex);
155	pthread_cond_broadcast(&cond_var);
156	pthread_mutex_unlock(&cond_mutex);
157
158	for (i = 0; i < 10000; i++) {
159		if (i % 100 == 0) {
160			printf("Noise Thread %d loop %d pthread pol %d "
161			       "pri %d\n", tid, i, pthr->policy,
162			       pthr->priority);
163			fflush(NULL);
164		}
165		busy_work_ms(1);
166	}
167	return NULL;
168}
169
170/*
171 * Test pthread creation at different thread priorities.
172 */
173int main(int argc, char *argv[])
174{
175	int i, retc, nopi = 0;
176	cpu_set_t mask;
177	CPU_ZERO(&mask);
178	CPU_SET(0, &mask);
179	setup();
180	rt_init("h", parse_args, argc, argv);
181
182	retc = pthread_barrier_init(&barrier, NULL, 5);
183	if (retc) {
184		printf("pthread_barrier_init failed: %s\n", strerror(retc));
185		exit(retc);
186	}
187
188	retc = sched_setaffinity(0, sizeof(mask), &mask);
189	if (retc < 0) {
190		printf("Main Thread: Can't set affinity: %d %s\n", retc,
191		       strerror(retc));
192		exit(-1);
193	}
194
195	for (i = 0; i < argc; i++) {
196		if (strcmp(argv[i], "nopi") == 0)
197			nopi = 1;
198	}
199
200	printf("Start %s\n", argv[0]);
201
202	if (!nopi)
203		init_pi_mutex(&glob_mutex);
204
205	create_rr_thread(func_lowrt, NULL, 10);
206	create_rr_thread(func_rt, NULL, 20);
207	create_fifo_thread(func_rt, NULL, 30);
208	create_fifo_thread(func_rt, NULL, 40);
209	create_rr_thread(func_noise, NULL, 40);
210
211	printf("Joining threads\n");
212	join_threads();
213	printf("Done\n");
214	printf("Criteria: Low Priority Thread and High Priority Thread "
215	       "should prempt each other multiple times\n");
216
217	pthread_mutex_destroy(&glob_mutex);
218	pthread_mutex_destroy(&cond_mutex);
219	pthread_cond_destroy(&cond_var);
220
221	return 0;
222}
223