test_qsbr.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 #define _LGPL_SOURCE
  54 #include "urcu-qsbr.h"
  55
  56 struct test_array {
  57         int a;
  58 };
  59
  60 static volatile int test_go, test_stop;
  61
  62 static int wdelay;
  63
  64 static struct test_array *test_rcu_pointer;
  65
  66 static unsigned long duration;
  67
  68 /* read-side C.S. duration, in loops */
  69 static unsigned long rduration;
  70
  71 static inline void loop_sleep(unsigned long l)
  72 {
  73         while(l-- != 0)
  74                 cpu_relax();
  75 }
  76
  77 /*
  78  * returns 0 if test should end.
  79  */
  80 static int test_duration_write(void)
  81 {
  82         return !test_stop;
  83 }
  84
  85 static int test_duration_read(void)
  86 {
  87         return !test_stop;
  88 }
  89
  90 static unsigned long long __thread nr_writes;
  91 static unsigned long long __thread nr_reads;
  92
  93 static unsigned int nr_readers;
  94 static unsigned int nr_writers;
  95
  96 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
  97
  98 void rcu_copy_mutex_lock(void)
  99 {
 100         int ret;
 101         ret = pthread_mutex_lock(&rcu_copy_mutex);
 102         if (ret) {
 103                 perror("Error in pthread mutex lock");
 104                 exit(-1);
 105         }
 106 }
 107
 108 void rcu_copy_mutex_unlock(void)
 109 {
 110         int ret;
 111
 112         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 113         if (ret) {
 114                 perror("Error in pthread mutex unlock");
 115                 exit(-1);
 116         }
 117 }
 118
 119 /*
 120  * malloc/free are reusing memory areas too quickly, which does not let us
 121  * test races appropriately. Use a large circular array for allocations.
 122  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 123  */
 124 #define ARRAY_SIZE (1048576 * nr_writers)
 125 #define ARRAY_POISON 0xDEADBEEF
 126 static int array_index;
 127 static struct test_array *test_array;
 128
 129 static struct test_array *test_array_alloc(void)
 130 {
 131         struct test_array *ret;
 132         int index;
 133
 134         rcu_copy_mutex_lock();
 135         index = array_index % ARRAY_SIZE;
 136         assert(test_array[index].a == ARRAY_POISON ||
 137                 test_array[index].a == 0);
 138         ret = &test_array[index];
 139         array_index++;
 140         if (array_index == ARRAY_SIZE)
 141                 array_index = 0;
 142         rcu_copy_mutex_unlock();
 143         return ret;
 144 }
 145
 146 static void test_array_free(struct test_array *ptr)
 147 {
 148         if (!ptr)
 149                 return;
 150         rcu_copy_mutex_lock();
 151         ptr->a = ARRAY_POISON;
 152         rcu_copy_mutex_unlock();
 153 }
 154
 155 void *thr_reader(void *_count)
 156 {
 157         unsigned long long *count = _count;
 158         struct test_array *local_ptr;
 159
 160         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 161                         "reader", pthread_self(), (unsigned long)gettid());
 162
 163         rcu_register_thread();
 164
 165         while (!test_go)
 166         {
 167         }
 168         smp_mb();
 169
 170         for (;;) {
 171                 _rcu_read_lock();
 172                 local_ptr = _rcu_dereference(test_rcu_pointer);
 173                 debug_yield_read();
 174                 if (local_ptr)
 175                         assert(local_ptr->a == 8);
 176                 if (unlikely(rduration))
 177                         loop_sleep(rduration);
 178                 _rcu_read_unlock();
 179                 nr_reads++;
 180                 /* QS each 1024 reads */
 181                 if (unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 182                         _rcu_quiescent_state();
 183                 if (unlikely(!test_duration_read()))
 184                         break;
 185         }
 186
 187         rcu_unregister_thread();
 188
 189         *count = nr_reads;
 190         printf("thread_end %s, thread id : %lx, tid %lu\n",
 191                         "reader", pthread_self(), (unsigned long)gettid());
 192         return ((void*)1);
 193
 194 }
 195
 196 void *thr_writer(void *_count)
 197 {
 198         unsigned long long *count = _count;
 199         struct test_array *new, *old;
 200
 201         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 202                         "writer", pthread_self(), (unsigned long)gettid());
 203
 204         while (!test_go)
 205         {
 206         }
 207         smp_mb();
 208
 209         for (;;) {
 210                 new = test_array_alloc();
 211                 rcu_copy_mutex_lock();
 212                 old = test_rcu_pointer;
 213                 if (old)
 214                         assert(old->a == 8);
 215                 new->a = 8;
 216                 old = _rcu_publish_content(&test_rcu_pointer, new);
 217                 rcu_copy_mutex_unlock();
 218                 /* can be done after unlock */
 219                 if (old)
 220                         old->a = 0;
 221                 test_array_free(old);
 222                 nr_writes++;
 223                 if (unlikely(!test_duration_write()))
 224                         break;
 225                 if (unlikely(wdelay))
 226                         usleep(wdelay);
 227         }
 228
 229         printf("thread_end %s, thread id : %lx, tid %lu\n",
 230                         "writer", pthread_self(), (unsigned long)gettid());
 231         *count = nr_writes;
 232         return ((void*)2);
 233 }
 234
 235 void show_usage(int argc, char **argv)
 236 {
 237         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 238 #ifdef DEBUG_YIELD
 239         printf(" [-r] [-w] (yield reader and/or writer)");
 240 #endif
 241         printf(" [-d delay] (writer period (us))");
 242         printf(" [-c duration] (reader C.S. duration (in loops))");
 243         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 244         printf("\n");
 245 }
 246
 247 cpu_set_t affinity;
 248
 249 int main(int argc, char **argv)
 250 {
 251         int err;
 252         pthread_t *tid_reader, *tid_writer;
 253         void *tret;
 254         unsigned long long *count_reader, *count_writer;
 255         unsigned long long tot_reads = 0, tot_writes = 0;
 256         int i, a;
 257         int use_affinity = 0;
 258
 259         if (argc < 4) {
 260                 show_usage(argc, argv);
 261                 return -1;
 262         }
 263
 264         err = sscanf(argv[1], "%u", &nr_readers);
 265         if (err != 1) {
 266                 show_usage(argc, argv);
 267                 return -1;
 268         }
 269
 270         err = sscanf(argv[2], "%u", &nr_writers);
 271         if (err != 1) {
 272                 show_usage(argc, argv);
 273                 return -1;
 274         }
 275
 276         err = sscanf(argv[3], "%lu", &duration);
 277         if (err != 1) {
 278                 show_usage(argc, argv);
 279                 return -1;
 280         }
 281
 282         CPU_ZERO(&affinity);
 283
 284         for (i = 4; i < argc; i++) {
 285                 if (argv[i][0] != '-')
 286                         continue;
 287                 switch (argv[i][1]) {
 288 #ifdef DEBUG_YIELD
 289                 case 'r':
 290                         yield_active |= YIELD_READ;
 291                         break;
 292                 case 'w':
 293                         yield_active |= YIELD_WRITE;
 294                         break;
 295 #endif
 296                 case 'a':
 297                         if (argc < i + 2) {
 298                                 show_usage(argc, argv);
 299                                 return -1;
 300                         }
 301                         a = atoi(argv[++i]);
 302                         CPU_SET(a, &affinity);
 303                         use_affinity = 1;
 304                         printf("Adding CPU %d affinity\n", a);
 305                         break;
 306                 case 'c':
 307                         if (argc < i + 2) {
 308                                 show_usage(argc, argv);
 309                                 return -1;
 310                         }
 311                         rduration = atoi(argv[++i]);
 312                         break;
 313                 case 'd':
 314                         if (argc < i + 2) {
 315                                 show_usage(argc, argv);
 316                                 return -1;
 317                         }
 318                         wdelay = atoi(argv[++i]);
 319                         break;
 320                 }
 321         }
 322
 323         printf("running test for %lu seconds, %u readers, %u writers.\n",
 324                 duration, nr_readers, nr_writers);
 325         printf("Writer delay : %u us.\n", wdelay);
 326         printf("thread %-6s, thread id : %lx, tid %lu\n",
 327                         "main", pthread_self(), (unsigned long)gettid());
 328
 329         if (use_affinity
 330             && sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
 331                 perror("sched_setaffinity");
 332                 exit(-1);
 333         }
 334
 335         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 336         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 337         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 338         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 339         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 340
 341         for (i = 0; i < nr_readers; i++) {
 342                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 343                                      &count_reader[i]);
 344                 if (err != 0)
 345                         exit(1);
 346         }
 347         for (i = 0; i < nr_writers; i++) {
 348                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 349                                      &count_writer[i]);
 350                 if (err != 0)
 351                         exit(1);
 352         }
 353
 354         smp_mb();
 355
 356         test_go = 1;
 357
 358         sleep(duration);
 359
 360         test_stop = 1;
 361
 362         for (i = 0; i < nr_readers; i++) {
 363                 err = pthread_join(tid_reader[i], &tret);
 364                 if (err != 0)
 365                         exit(1);
 366                 tot_reads += count_reader[i];
 367         }
 368         for (i = 0; i < nr_writers; i++) {
 369                 err = pthread_join(tid_writer[i], &tret);
 370                 if (err != 0)
 371                         exit(1);
 372                 tot_writes += count_writer[i];
 373         }
 374
 375         printf("total number of reads : %llu, writes %llu\n", tot_reads,
 376                tot_writes);
 377         test_array_free(test_rcu_pointer);
 378         free(test_array);
 379         free(tid_reader);
 380         free(tid_writer);
 381         free(count_reader);
 382         free(count_writer);
 383         return 0;
 384 }