test_urcu.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 /* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
  39 #define CACHE_LINE_SIZE 4096
  40
  41 #if defined(_syscall0)
  42 _syscall0(pid_t, gettid)
  43 #elif defined(__NR_gettid)
  44 static inline pid_t gettid(void)
  45 {
  46         return syscall(__NR_gettid);
  47 }
  48 #else
  49 #warning "use pid as tid"
  50 static inline pid_t gettid(void)
  51 {
  52         return getpid();
  53 }
  54 #endif
  55
  56 #ifndef DYNAMIC_LINK_TEST
  57 #define _LGPL_SOURCE
  58 #else
  59 #define debug_yield_read()
  60 #endif
  61 #include "urcu.h"
  62
  63 struct test_array {
  64         int a;
  65 };
  66
  67 static volatile int test_go, test_stop;
  68
  69 static unsigned long wdelay;
  70
  71 static struct test_array *test_rcu_pointer;
  72
  73 static unsigned long duration;
  74
  75 /* read-side C.S. duration, in loops */
  76 static unsigned long rduration;
  77
  78 static inline void loop_sleep(unsigned long l)
  79 {
  80         while(l-- != 0)
  81                 cpu_relax();
  82 }
  83
  84 static int verbose_mode;
  85
  86 #define printf_verbose(fmt, args...)            \
  87         do {                                    \
  88                 if (verbose_mode)               \
  89                         printf(fmt, args);      \
  90         } while (0)
  91
  92 /*
  93  * returns 0 if test should end.
  94  */
  95 static int test_duration_write(void)
  96 {
  97         return !test_stop;
  98 }
  99
 100 static int test_duration_read(void)
 101 {
 102         return !test_stop;
 103 }
 104
 105 static unsigned long long __thread nr_writes;
 106 static unsigned long long __thread nr_reads;
 107
 108 static unsigned int nr_readers;
 109 static unsigned int nr_writers;
 110
 111 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 112
 113 void rcu_copy_mutex_lock(void)
 114 {
 115         int ret;
 116         ret = pthread_mutex_lock(&rcu_copy_mutex);
 117         if (ret) {
 118                 perror("Error in pthread mutex lock");
 119                 exit(-1);
 120         }
 121 }
 122
 123 void rcu_copy_mutex_unlock(void)
 124 {
 125         int ret;
 126
 127         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 128         if (ret) {
 129                 perror("Error in pthread mutex unlock");
 130                 exit(-1);
 131         }
 132 }
 133
 134 /*
 135  * malloc/free are reusing memory areas too quickly, which does not let us
 136  * test races appropriately. Use a large circular array for allocations.
 137  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 138  */
 139 #define ARRAY_SIZE (1048576 * nr_writers)
 140 #define ARRAY_POISON 0xDEADBEEF
 141 static int array_index;
 142 static struct test_array *test_array;
 143
 144 static struct test_array *test_array_alloc(void)
 145 {
 146         struct test_array *ret;
 147         int index;
 148
 149         rcu_copy_mutex_lock();
 150         index = array_index % ARRAY_SIZE;
 151         assert(test_array[index].a == ARRAY_POISON ||
 152                 test_array[index].a == 0);
 153         ret = &test_array[index];
 154         array_index++;
 155         if (array_index == ARRAY_SIZE)
 156                 array_index = 0;
 157         rcu_copy_mutex_unlock();
 158         return ret;
 159 }
 160
 161 static void test_array_free(struct test_array *ptr)
 162 {
 163         if (!ptr)
 164                 return;
 165         rcu_copy_mutex_lock();
 166         ptr->a = ARRAY_POISON;
 167         rcu_copy_mutex_unlock();
 168 }
 169
 170 void *thr_reader(void *_count)
 171 {
 172         unsigned long long *count = _count;
 173         struct test_array *local_ptr;
 174
 175         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 176                         "reader", pthread_self(), (unsigned long)gettid());
 177
 178         rcu_register_thread();
 179
 180         while (!test_go)
 181         {
 182         }
 183         smp_mb();
 184
 185         for (;;) {
 186                 rcu_read_lock();
 187                 local_ptr = rcu_dereference(test_rcu_pointer);
 188                 debug_yield_read();
 189                 if (local_ptr)
 190                         assert(local_ptr->a == 8);
 191                 if (unlikely(rduration))
 192                         loop_sleep(rduration);
 193                 rcu_read_unlock();
 194                 nr_reads++;
 195                 if (unlikely(!test_duration_read()))
 196                         break;
 197         }
 198
 199         rcu_unregister_thread();
 200
 201         *count = nr_reads;
 202         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 203                         "reader", pthread_self(), (unsigned long)gettid());
 204         return ((void*)1);
 205
 206 }
 207
 208 void *thr_writer(void *_count)
 209 {
 210         unsigned long long *count = _count;
 211         struct test_array *new, *old;
 212
 213         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 214                         "writer", pthread_self(), (unsigned long)gettid());
 215
 216         while (!test_go)
 217         {
 218         }
 219         smp_mb();
 220
 221         for (;;) {
 222                 new = test_array_alloc();
 223                 rcu_copy_mutex_lock();
 224                 old = test_rcu_pointer;
 225                 if (old)
 226                         assert(old->a == 8);
 227                 new->a = 8;
 228                 old = rcu_publish_content(&test_rcu_pointer, new);
 229                 rcu_copy_mutex_unlock();
 230                 /* can be done after unlock */
 231                 if (old)
 232                         old->a = 0;
 233                 test_array_free(old);
 234                 nr_writes++;
 235                 if (unlikely(!test_duration_write()))
 236                         break;
 237                 if (unlikely(wdelay))
 238                         loop_sleep(wdelay);
 239         }
 240
 241         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 242                         "writer", pthread_self(), (unsigned long)gettid());
 243         *count = nr_writes;
 244         return ((void*)2);
 245 }
 246
 247 void show_usage(int argc, char **argv)
 248 {
 249         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 250 #ifdef DEBUG_YIELD
 251         printf(" [-r] [-w] (yield reader and/or writer)");
 252 #endif
 253         printf(" [-d delay] (writer period (us))");
 254         printf(" [-c duration] (reader C.S. duration (in loops))");
 255         printf(" [-v] (verbose output)");
 256         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 257         printf("\n");
 258 }
 259
 260 cpu_set_t affinity;
 261
 262 int main(int argc, char **argv)
 263 {
 264         int err;
 265         pthread_t *tid_reader, *tid_writer;
 266         void *tret;
 267         unsigned long long *count_reader, *count_writer;
 268         unsigned long long tot_reads = 0, tot_writes = 0;
 269         int i, a;
 270         int use_affinity = 0;
 271
 272         if (argc < 4) {
 273                 show_usage(argc, argv);
 274                 return -1;
 275         }
 276
 277         err = sscanf(argv[1], "%u", &nr_readers);
 278         if (err != 1) {
 279                 show_usage(argc, argv);
 280                 return -1;
 281         }
 282
 283         err = sscanf(argv[2], "%u", &nr_writers);
 284         if (err != 1) {
 285                 show_usage(argc, argv);
 286                 return -1;
 287         }
 288
 289         err = sscanf(argv[3], "%lu", &duration);
 290         if (err != 1) {
 291                 show_usage(argc, argv);
 292                 return -1;
 293         }
 294
 295         CPU_ZERO(&affinity);
 296
 297         for (i = 4; i < argc; i++) {
 298                 if (argv[i][0] != '-')
 299                         continue;
 300                 switch (argv[i][1]) {
 301 #ifdef DEBUG_YIELD
 302                 case 'r':
 303                         yield_active |= YIELD_READ;
 304                         break;
 305                 case 'w':
 306                         yield_active |= YIELD_WRITE;
 307                         break;
 308 #endif
 309                 case 'a':
 310                         if (argc < i + 2) {
 311                                 show_usage(argc, argv);
 312                                 return -1;
 313                         }
 314                         a = atoi(argv[++i]);
 315                         CPU_SET(a, &affinity);
 316                         use_affinity = 1;
 317                         printf_verbose("Adding CPU %d affinity\n", a);
 318                         break;
 319                 case 'c':
 320                         if (argc < i + 2) {
 321                                 show_usage(argc, argv);
 322                                 return -1;
 323                         }
 324                         rduration = atol(argv[++i]);
 325                         break;
 326                 case 'd':
 327                         if (argc < i + 2) {
 328                                 show_usage(argc, argv);
 329                                 return -1;
 330                         }
 331                         wdelay = atol(argv[++i]);
 332                         break;
 333                 case 'v':
 334                         verbose_mode = 1;
 335                         break;
 336                 }
 337         }
 338
 339         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 340                 duration, nr_readers, nr_writers);
 341         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 342         printf_verbose("Reader duration : %lu loops.\n", rduration);
 343         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 344                         "main", pthread_self(), (unsigned long)gettid());
 345
 346         if (use_affinity
 347             && sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
 348                 perror("sched_setaffinity");
 349                 exit(-1);
 350         }
 351
 352         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 353         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 354         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 355         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 356         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 357
 358         for (i = 0; i < nr_readers; i++) {
 359                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 360                                      &count_reader[i]);
 361                 if (err != 0)
 362                         exit(1);
 363         }
 364         for (i = 0; i < nr_writers; i++) {
 365                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 366                                      &count_writer[i]);
 367                 if (err != 0)
 368                         exit(1);
 369         }
 370
 371         smp_mb();
 372
 373         test_go = 1;
 374
 375         sleep(duration);
 376
 377         test_stop = 1;
 378
 379         for (i = 0; i < nr_readers; i++) {
 380                 err = pthread_join(tid_reader[i], &tret);
 381                 if (err != 0)
 382                         exit(1);
 383                 tot_reads += count_reader[i];
 384         }
 385         for (i = 0; i < nr_writers; i++) {
 386                 err = pthread_join(tid_writer[i], &tret);
 387                 if (err != 0)
 388                         exit(1);
 389                 tot_writes += count_writer[i];
 390         }
 391
 392         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 393                tot_writes);
 394         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 395                 "nr_writers %3u "
 396                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 397                 argv[0], duration, nr_readers, rduration,
 398                 nr_writers, wdelay, tot_reads, tot_writes,
 399                 tot_reads + tot_writes);
 400         test_array_free(test_rcu_pointer);
 401         free(test_array);
 402         free(tid_reader);
 403         free(tid_writer);
 404         free(count_reader);
 405         free(count_writer);
 406         return 0;
 407 }