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-1.c 21 * 22 * DESCRIPTION 23 * This testcase verifies if the low priority SCHED_OTHER thread can preempt 24 * the high priority SCHED_RR thread via priority inheritance. 25 * 26 * USAGE: 27 * Use run_auto.sh script in current directory to build and run test. 28 * 29 * AUTHOR 30 * 31 * 32 * HISTORY 33 * 2010-04-22 Code cleanup and thread synchronization changes by using 34 * conditional variables, 35 * by Gowrishankar(gowrishankar.m (at) in.ibm.com). 36 * 37 *****************************************************************************/ 38 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <sched.h> 43 #include <pthread.h> 44 #include <sys/types.h> 45 #include <sys/syscall.h> 46 #include <unistd.h> 47 #include <librttest.h> 48 49 pthread_barrier_t barrier; 50 51 void usage(void) 52 { 53 rt_help(); 54 printf("testpi-1 specific options:\n"); 55 } 56 57 int parse_args(int c, char *v) 58 { 59 int handled = 1; 60 switch (c) { 61 case 'h': 62 usage(); 63 exit(0); 64 default: 65 handled = 0; 66 break; 67 } 68 return handled; 69 } 70 71 int gettid(void) 72 { 73 return syscall(__NR_gettid); 74 } 75 76 typedef void *(*entrypoint_t) (void *); 77 pthread_mutex_t glob_mutex; 78 static pthread_mutex_t cond_mutex = PTHREAD_MUTEX_INITIALIZER; 79 static pthread_cond_t cond_var = PTHREAD_COND_INITIALIZER; 80 81 void *func_nonrt(void *arg) 82 { 83 struct thread *pthr = (struct thread *)arg; 84 int i, tid = gettid(); 85 86 printf("Thread %d started running with priority %d\n", tid, 87 pthr->priority); 88 pthread_mutex_lock(&glob_mutex); 89 printf("Thread %d at start pthread pol %d pri %d - Got global lock\n", 90 tid, pthr->policy, pthr->priority); 91 /* Wait for other RT threads to start up */ 92 pthread_barrier_wait(&barrier); 93 94 /* Wait for the high priority noise thread to start and signal us */ 95 pthread_mutex_lock(&cond_mutex); 96 pthread_cond_wait(&cond_var, &cond_mutex); 97 pthread_mutex_unlock(&cond_mutex); 98 99 for (i = 0; i < 10000; i++) { 100 if (i % 100 == 0) { 101 printf("Thread %d loop %d pthread pol %d pri %d\n", 102 tid, i, pthr->policy, pthr->priority); 103 fflush(NULL); 104 } 105 busy_work_ms(1); 106 } 107 pthread_mutex_unlock(&glob_mutex); 108 return NULL; 109 } 110 111 void *func_rt(void *arg) 112 { 113 struct thread *pthr = (struct thread *)arg; 114 int i, tid = gettid(); 115 116 printf("Thread %d started running with prio %d\n", tid, pthr->priority); 117 pthread_barrier_wait(&barrier); 118 pthread_mutex_lock(&glob_mutex); 119 printf("Thread %d at start pthread pol %d pri %d - Got global lock\n", 120 tid, pthr->policy, pthr->priority); 121 122 /* We just use the mutex as something to slow things down, 123 * say who we are and then do nothing for a while. The aim 124 * of this is to show that high priority threads make more 125 * progress than lower priority threads.. 126 */ 127 for (i = 0; i < 1000; i++) { 128 if (i % 100 == 0) { 129 printf("Thread %d loop %d pthread pol %d pri %d\n", 130 tid, i, pthr->policy, pthr->priority); 131 fflush(NULL); 132 } 133 busy_work_ms(1); 134 } 135 pthread_mutex_unlock(&glob_mutex); 136 return NULL; 137 } 138 139 void *func_noise(void *arg) 140 { 141 struct thread *pthr = (struct thread *)arg; 142 int i, tid = gettid(); 143 144 printf("Noise Thread %d started running with prio %d\n", tid, 145 pthr->priority); 146 pthread_barrier_wait(&barrier); 147 148 /* Let others wait at conditional variable */ 149 usleep(1000); 150 151 /* Noise thread begins the test */ 152 pthread_mutex_lock(&cond_mutex); 153 pthread_cond_broadcast(&cond_var); 154 pthread_mutex_unlock(&cond_mutex); 155 156 for (i = 0; i < 10000; i++) { 157 if (i % 100 == 0) { 158 printf("Noise Thread %d loop %d pthread pol %d " 159 "pri %d\n", tid, i, pthr->policy, 160 pthr->priority); 161 fflush(NULL); 162 } 163 busy_work_ms(1); 164 } 165 return NULL; 166 } 167 168 /* 169 * Test pthread creation at different thread priorities. 170 */ 171 int main(int argc, char *argv[]) 172 { 173 int i, retc, nopi = 0; 174 cpu_set_t mask; 175 CPU_ZERO(&mask); 176 CPU_SET(0, &mask); 177 setup(); 178 179 rt_init("h", parse_args, argc, argv); 180 181 retc = pthread_barrier_init(&barrier, NULL, 5); 182 if (retc) { 183 printf("pthread_barrier_init failed: %s\n", strerror(retc)); 184 exit(retc); 185 } 186 187 retc = sched_setaffinity(0, sizeof(mask), &mask); 188 if (retc < 0) { 189 printf("Main Thread: Can't set affinity: %d %s\n", retc, 190 strerror(retc)); 191 exit(-1); 192 } 193 194 for (i = 0; i < argc; i++) { 195 if (strcmp(argv[i], "nopi") == 0) 196 nopi = 1; 197 } 198 199 printf("Start %s\n", argv[0]); 200 201 if (!nopi) 202 init_pi_mutex(&glob_mutex); 203 204 create_other_thread(func_nonrt, NULL); 205 create_rr_thread(func_rt, NULL, 20); 206 create_rr_thread(func_rt, NULL, 30); 207 create_rr_thread(func_rt, NULL, 40); 208 create_rr_thread(func_noise, NULL, 40); 209 210 printf("Joining threads\n"); 211 join_threads(); 212 printf("Done\n"); 213 printf("Criteria:Low Priority Thread should Preempt Higher Priority " 214 "Noise Thread\n"); 215 216 pthread_mutex_destroy(&glob_mutex); 217 pthread_mutex_destroy(&cond_mutex); 218 pthread_cond_destroy(&cond_var); 219 220 return 0; 221 } 222
