test_rwlock.c

   1 /*
   2  * test_urcu.c
   3  *
   4  * Userspace RCU library - test program
   5  *
   6  * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #include <pthread.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30 #include <unistd.h>
  31 #include <stdio.h>
  32 #include <assert.h>
  33 #include <sys/syscall.h>
  34 #include <sched.h>
  35
  36 #include "arch.h"
  37
  38 #if defined(_syscall0)
  39 _syscall0(pid_t, gettid)
  40 #elif defined(__NR_gettid)
  41 static inline pid_t gettid(void)
  42 {
  43         return syscall(__NR_gettid);
  44 }
  45 #else
  46 #warning "use pid as tid"
  47 static inline pid_t gettid(void)
  48 {
  49         return getpid();
  50 }
  51 #endif
  52
  53 #ifndef DYNAMIC_LINK_TEST
  54 #define _LGPL_SOURCE
  55 #else
  56 #define debug_yield_read()
  57 #endif
  58 #include "urcu.h"
  59
  60 struct test_array {
  61         int a;
  62 };
  63
  64 pthread_rwlock_t lock = PTHREAD_RWLOCK_INITIALIZER;
  65
  66 static volatile int test_go, test_stop;
  67
  68 static int wdelay;
  69
  70 static volatile struct test_array test_array = { 8 };
  71
  72 static unsigned long duration;
  73
  74 /* read-side C.S. duration, in loops */
  75 static unsigned long rduration;
  76
  77 static inline void loop_sleep(unsigned long l)
  78 {
  79         while(l-- != 0)
  80                 cpu_relax();
  81 }
  82
  83 /*
  84  * returns 0 if test should end.
  85  */
  86 static int test_duration_write(void)
  87 {
  88         return !test_stop;
  89 }
  90
  91 static int test_duration_read(void)
  92 {
  93         return !test_stop;
  94 }
  95
  96 static unsigned long long __thread nr_writes;
  97 static unsigned long long __thread nr_reads;
  98
  99 static unsigned int nr_readers;
 100 static unsigned int nr_writers;
 101
 102 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 103
 104 void rcu_copy_mutex_lock(void)
 105 {
 106         int ret;
 107         ret = pthread_mutex_lock(&rcu_copy_mutex);
 108         if (ret) {
 109                 perror("Error in pthread mutex lock");
 110                 exit(-1);
 111         }
 112 }
 113
 114 void rcu_copy_mutex_unlock(void)
 115 {
 116         int ret;
 117
 118         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 119         if (ret) {
 120                 perror("Error in pthread mutex unlock");
 121                 exit(-1);
 122         }
 123 }
 124
 125 void *thr_reader(void *_count)
 126 {
 127         unsigned long long *count = _count;
 128
 129         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 130                         "reader", pthread_self(), (unsigned long)gettid());
 131
 132         while (!test_go)
 133         {
 134         }
 135
 136         for (;;) {
 137                 pthread_rwlock_rdlock(&lock);
 138                 assert(test_array.a == 8);
 139                 if (unlikely(rduration))
 140                         loop_sleep(rduration);
 141                 pthread_rwlock_unlock(&lock);
 142                 nr_reads++;
 143                 if (unlikely(!test_duration_read()))
 144                         break;
 145         }
 146
 147         *count = nr_reads;
 148         printf("thread_end %s, thread id : %lx, tid %lu\n",
 149                         "reader", pthread_self(), (unsigned long)gettid());
 150         return ((void*)1);
 151
 152 }
 153
 154 void *thr_writer(void *_count)
 155 {
 156         unsigned long long *count = _count;
 157
 158         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 159                         "writer", pthread_self(), (unsigned long)gettid());
 160
 161         while (!test_go)
 162         {
 163         }
 164         smp_mb();
 165
 166         for (;;) {
 167                 pthread_rwlock_wrlock(&lock);
 168                 test_array.a = 0;
 169                 test_array.a = 8;
 170                 pthread_rwlock_unlock(&lock);
 171                 nr_writes++;
 172                 if (unlikely(!test_duration_write()))
 173                         break;
 174                 if (unlikely(wdelay))
 175                         usleep(wdelay);
 176         }
 177
 178         printf("thread_end %s, thread id : %lx, tid %lu\n",
 179                         "writer", pthread_self(), (unsigned long)gettid());
 180         *count = nr_writes;
 181         return ((void*)2);
 182 }
 183
 184 void show_usage(int argc, char **argv)
 185 {
 186         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 187 #ifdef DEBUG_YIELD
 188         printf(" [-r] [-w] (yield reader and/or writer)");
 189 #endif
 190         printf(" [-d delay] (writer period (us))");
 191         printf(" [-c duration] (reader C.S. duration (in loops))");
 192         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 193         printf("\n");
 194 }
 195
 196 cpu_set_t affinity;
 197
 198 int main(int argc, char **argv)
 199 {
 200         int err;
 201         pthread_t *tid_reader, *tid_writer;
 202         void *tret;
 203         unsigned long long *count_reader, *count_writer;
 204         unsigned long long tot_reads = 0, tot_writes = 0;
 205         int i, a;
 206         int use_affinity = 0;
 207
 208         if (argc < 4) {
 209                 show_usage(argc, argv);
 210                 return -1;
 211         }
 212         smp_mb();
 213
 214         err = sscanf(argv[1], "%u", &nr_readers);
 215         if (err != 1) {
 216                 show_usage(argc, argv);
 217                 return -1;
 218         }
 219
 220         err = sscanf(argv[2], "%u", &nr_writers);
 221         if (err != 1) {
 222                 show_usage(argc, argv);
 223                 return -1;
 224         }
 225
 226         err = sscanf(argv[3], "%lu", &duration);
 227         if (err != 1) {
 228                 show_usage(argc, argv);
 229                 return -1;
 230         }
 231
 232         CPU_ZERO(&affinity);
 233
 234         for (i = 4; i < argc; i++) {
 235                 if (argv[i][0] != '-')
 236                         continue;
 237                 switch (argv[i][1]) {
 238 #ifdef DEBUG_YIELD
 239                 case 'r':
 240                         yield_active |= YIELD_READ;
 241                         break;
 242                 case 'w':
 243                         yield_active |= YIELD_WRITE;
 244                         break;
 245 #endif
 246                 case 'a':
 247                         if (argc < i + 2) {
 248                                 show_usage(argc, argv);
 249                                 return -1;
 250                         }
 251                         a = atoi(argv[++i]);
 252                         CPU_SET(a, &affinity);
 253                         use_affinity = 1;
 254                         printf("Adding CPU %d affinity\n", a);
 255                         break;
 256                 case 'c':
 257                         if (argc < i + 2) {
 258                                 show_usage(argc, argv);
 259                                 return -1;
 260                         }
 261                         rduration = atoi(argv[++i]);
 262                         break;
 263                 case 'd':
 264                         if (argc < i + 2) {
 265                                 show_usage(argc, argv);
 266                                 return -1;
 267                         }
 268                         wdelay = atoi(argv[++i]);
 269                         break;
 270                 }
 271         }
 272
 273         printf("running test for %lu seconds, %u readers, %u writers.\n",
 274                 duration, nr_readers, nr_writers);
 275         printf("Writer delay : %u us.\n", wdelay);
 276         printf("thread %-6s, thread id : %lx, tid %lu\n",
 277                         "main", pthread_self(), (unsigned long)gettid());
 278         if (use_affinity
 279             && sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
 280                 perror("sched_setaffinity");
 281                 exit(-1);
 282         }
 283
 284         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 285         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 286         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 287         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 288
 289         for (i = 0; i < nr_readers; i++) {
 290                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 291                                      &count_reader[i]);
 292                 if (err != 0)
 293                         exit(1);
 294         }
 295         for (i = 0; i < nr_writers; i++) {
 296                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 297                                      &count_writer[i]);
 298                 if (err != 0)
 299                         exit(1);
 300         }
 301
 302         smp_mb();
 303
 304         test_go = 1;
 305
 306         sleep(duration);
 307
 308         test_stop = 1;
 309
 310         for (i = 0; i < nr_readers; i++) {
 311                 err = pthread_join(tid_reader[i], &tret);
 312                 if (err != 0)
 313                         exit(1);
 314                 tot_reads += count_reader[i];
 315         }
 316         for (i = 0; i < nr_writers; i++) {
 317                 err = pthread_join(tid_writer[i], &tret);
 318                 if (err != 0)
 319                         exit(1);
 320                 tot_writes += count_writer[i];
 321         }
 322
 323         printf("total number of reads : %llu, writes %llu\n", tot_reads,
 324                tot_writes);
 325         free(tid_reader);
 326         free(tid_writer);
 327         free(count_reader);
 328         free(count_writer);
 329         return 0;
 330 }