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 static int verbose_mode;
  78
  79 #define printf_verbose(fmt, args...)            \
  80         do {                                    \
  81                 if (verbose_mode)               \
  82                         printf(fmt, args);      \
  83         } while (0)
  84
  85 /*
  86  * returns 0 if test should end.
  87  */
  88 static int test_duration_write(void)
  89 {
  90         return !test_stop;
  91 }
  92
  93 static int test_duration_read(void)
  94 {
  95         return !test_stop;
  96 }
  97
  98 static unsigned long long __thread nr_writes;
  99 static unsigned long long __thread nr_reads;
 100
 101 static unsigned int nr_readers;
 102 static unsigned int nr_writers;
 103
 104 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 105
 106 void rcu_copy_mutex_lock(void)
 107 {
 108         int ret;
 109         ret = pthread_mutex_lock(&rcu_copy_mutex);
 110         if (ret) {
 111                 perror("Error in pthread mutex lock");
 112                 exit(-1);
 113         }
 114 }
 115
 116 void rcu_copy_mutex_unlock(void)
 117 {
 118         int ret;
 119
 120         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 121         if (ret) {
 122                 perror("Error in pthread mutex unlock");
 123                 exit(-1);
 124         }
 125 }
 126
 127 /*
 128  * malloc/free are reusing memory areas too quickly, which does not let us
 129  * test races appropriately. Use a large circular array for allocations.
 130  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 131  */
 132 #define ARRAY_SIZE (1048576 * nr_writers)
 133 #define ARRAY_POISON 0xDEADBEEF
 134 static int array_index;
 135 static struct test_array *test_array;
 136
 137 static struct test_array *test_array_alloc(void)
 138 {
 139         struct test_array *ret;
 140         int index;
 141
 142         rcu_copy_mutex_lock();
 143         index = array_index % ARRAY_SIZE;
 144         assert(test_array[index].a == ARRAY_POISON ||
 145                 test_array[index].a == 0);
 146         ret = &test_array[index];
 147         array_index++;
 148         if (array_index == ARRAY_SIZE)
 149                 array_index = 0;
 150         rcu_copy_mutex_unlock();
 151         return ret;
 152 }
 153
 154 static void test_array_free(struct test_array *ptr)
 155 {
 156         if (!ptr)
 157                 return;
 158         rcu_copy_mutex_lock();
 159         ptr->a = ARRAY_POISON;
 160         rcu_copy_mutex_unlock();
 161 }
 162
 163 void *thr_reader(void *_count)
 164 {
 165         unsigned long long *count = _count;
 166         struct test_array *local_ptr;
 167
 168         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 169                         "reader", pthread_self(), (unsigned long)gettid());
 170
 171         rcu_register_thread();
 172
 173         while (!test_go)
 174         {
 175         }
 176         smp_mb();
 177
 178         for (;;) {
 179                 _rcu_read_lock();
 180                 local_ptr = _rcu_dereference(test_rcu_pointer);
 181                 debug_yield_read();
 182                 if (local_ptr)
 183                         assert(local_ptr->a == 8);
 184                 if (unlikely(rduration))
 185                         loop_sleep(rduration);
 186                 _rcu_read_unlock();
 187                 nr_reads++;
 188                 /* QS each 1024 reads */
 189                 if (unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 190                         _rcu_quiescent_state();
 191                 if (unlikely(!test_duration_read()))
 192                         break;
 193         }
 194
 195         rcu_unregister_thread();
 196
 197         *count = nr_reads;
 198         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 199                         "reader", pthread_self(), (unsigned long)gettid());
 200         return ((void*)1);
 201
 202 }
 203
 204 void *thr_writer(void *_count)
 205 {
 206         unsigned long long *count = _count;
 207         struct test_array *new, *old;
 208
 209         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 210                         "writer", pthread_self(), (unsigned long)gettid());
 211
 212         while (!test_go)
 213         {
 214         }
 215         smp_mb();
 216
 217         for (;;) {
 218                 new = test_array_alloc();
 219                 rcu_copy_mutex_lock();
 220                 old = test_rcu_pointer;
 221                 if (old)
 222                         assert(old->a == 8);
 223                 new->a = 8;
 224                 old = _rcu_publish_content(&test_rcu_pointer, new);
 225                 rcu_copy_mutex_unlock();
 226                 /* can be done after unlock */
 227                 if (old)
 228                         old->a = 0;
 229                 test_array_free(old);
 230                 nr_writes++;
 231                 if (unlikely(!test_duration_write()))
 232                         break;
 233                 if (unlikely(wdelay))
 234                         usleep(wdelay);
 235         }
 236
 237         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 238                         "writer", pthread_self(), (unsigned long)gettid());
 239         *count = nr_writes;
 240         return ((void*)2);
 241 }
 242
 243 void show_usage(int argc, char **argv)
 244 {
 245         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 246 #ifdef DEBUG_YIELD
 247         printf(" [-r] [-w] (yield reader and/or writer)");
 248 #endif
 249         printf(" [-d delay] (writer period (us))");
 250         printf(" [-c duration] (reader C.S. duration (in loops))");
 251         printf(" [-v] (verbose output)");
 252         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 253         printf("\n");
 254 }
 255
 256 cpu_set_t affinity;
 257
 258 int main(int argc, char **argv)
 259 {
 260         int err;
 261         pthread_t *tid_reader, *tid_writer;
 262         void *tret;
 263         unsigned long long *count_reader, *count_writer;
 264         unsigned long long tot_reads = 0, tot_writes = 0;
 265         int i, a;
 266         int use_affinity = 0;
 267
 268         if (argc < 4) {
 269                 show_usage(argc, argv);
 270                 return -1;
 271         }
 272
 273         err = sscanf(argv[1], "%u", &nr_readers);
 274         if (err != 1) {
 275                 show_usage(argc, argv);
 276                 return -1;
 277         }
 278
 279         err = sscanf(argv[2], "%u", &nr_writers);
 280         if (err != 1) {
 281                 show_usage(argc, argv);
 282                 return -1;
 283         }
 284
 285         err = sscanf(argv[3], "%lu", &duration);
 286         if (err != 1) {
 287                 show_usage(argc, argv);
 288                 return -1;
 289         }
 290
 291         CPU_ZERO(&affinity);
 292
 293         for (i = 4; i < argc; i++) {
 294                 if (argv[i][0] != '-')
 295                         continue;
 296                 switch (argv[i][1]) {
 297 #ifdef DEBUG_YIELD
 298                 case 'r':
 299                         yield_active |= YIELD_READ;
 300                         break;
 301                 case 'w':
 302                         yield_active |= YIELD_WRITE;
 303                         break;
 304 #endif
 305                 case 'a':
 306                         if (argc < i + 2) {
 307                                 show_usage(argc, argv);
 308                                 return -1;
 309                         }
 310                         a = atoi(argv[++i]);
 311                         CPU_SET(a, &affinity);
 312                         use_affinity = 1;
 313                         printf_verbose("Adding CPU %d affinity\n", a);
 314                         break;
 315                 case 'c':
 316                         if (argc < i + 2) {
 317                                 show_usage(argc, argv);
 318                                 return -1;
 319                         }
 320                         rduration = atoi(argv[++i]);
 321                         break;
 322                 case 'd':
 323                         if (argc < i + 2) {
 324                                 show_usage(argc, argv);
 325                                 return -1;
 326                         }
 327                         wdelay = atoi(argv[++i]);
 328                         break;
 329                 case 'v':
 330                         verbose_mode = 1;
 331                         break;
 332                 }
 333         }
 334
 335         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 336                 duration, nr_readers, nr_writers);
 337         printf_verbose("Writer delay : %u us.\n", wdelay);
 338         printf_verbose("Reader duration : %lu loops.\n", rduration);
 339         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 340                         "main", pthread_self(), (unsigned long)gettid());
 341
 342         if (use_affinity
 343             && sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
 344                 perror("sched_setaffinity");
 345                 exit(-1);
 346         }
 347
 348         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 349         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 350         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 351         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 352         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 353
 354         for (i = 0; i < nr_readers; i++) {
 355                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 356                                      &count_reader[i]);
 357                 if (err != 0)
 358                         exit(1);
 359         }
 360         for (i = 0; i < nr_writers; i++) {
 361                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 362                                      &count_writer[i]);
 363                 if (err != 0)
 364                         exit(1);
 365         }
 366
 367         smp_mb();
 368
 369         test_go = 1;
 370
 371         sleep(duration);
 372
 373         test_stop = 1;
 374
 375         for (i = 0; i < nr_readers; i++) {
 376                 err = pthread_join(tid_reader[i], &tret);
 377                 if (err != 0)
 378                         exit(1);
 379                 tot_reads += count_reader[i];
 380         }
 381         for (i = 0; i < nr_writers; i++) {
 382                 err = pthread_join(tid_writer[i], &tret);
 383                 if (err != 0)
 384                         exit(1);
 385                 tot_writes += count_writer[i];
 386         }
 387
 388         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 389                tot_writes);
 390         printf("SUMMARY %s testdur %lu nr_readers %u rdur %lu nr_writers %u "
 391                 "wdelay %u nr_reads %llu nr_writes %llu nr_ops %llu\n",
 392                 argv[0], duration, nr_readers, rduration,
 393                 nr_writers, wdelay, tot_reads, tot_writes,
 394                 tot_reads + tot_writes);
 395         test_array_free(test_rcu_pointer);
 396         free(test_array);
 397         free(tid_reader);
 398         free(tid_writer);
 399         free(count_reader);
 400         free(count_writer);
 401         return 0;
 402 }