tests/test_urcu_assign.c

   1 /*
   2  * test_urcu_assign.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 <urcu/arch.h>
  37
  38 /* hardcoded number of CPUs */
  39 #define NR_CPUS 16384
  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 static unsigned int cpu_affinities[NR_CPUS];
  93 static unsigned int next_aff = 0;
  94 static int use_affinity = 0;
  95
  96 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
  97
  98 static void set_affinity(void)
  99 {
 100         cpu_set_t mask;
 101         int cpu;
 102         int ret;
 103
 104         if (!use_affinity)
 105                 return;
 106
 107         ret = pthread_mutex_lock(&affinity_mutex);
 108         if (ret) {
 109                 perror("Error in pthread mutex lock");
 110                 exit(-1);
 111         }
 112         cpu = cpu_affinities[next_aff++];
 113         ret = pthread_mutex_unlock(&affinity_mutex);
 114         if (ret) {
 115                 perror("Error in pthread mutex unlock");
 116                 exit(-1);
 117         }
 118         CPU_ZERO(&mask);
 119         CPU_SET(cpu, &mask);
 120         sched_setaffinity(0, sizeof(mask), &mask);
 121 }
 122
 123 /*
 124  * returns 0 if test should end.
 125  */
 126 static int test_duration_write(void)
 127 {
 128         return !test_stop;
 129 }
 130
 131 static int test_duration_read(void)
 132 {
 133         return !test_stop;
 134 }
 135
 136 static unsigned long long __thread nr_writes;
 137 static unsigned long long __thread nr_reads;
 138
 139 static unsigned int nr_readers;
 140 static unsigned int nr_writers;
 141
 142 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 143
 144 void rcu_copy_mutex_lock(void)
 145 {
 146         int ret;
 147         ret = pthread_mutex_lock(&rcu_copy_mutex);
 148         if (ret) {
 149                 perror("Error in pthread mutex lock");
 150                 exit(-1);
 151         }
 152 }
 153
 154 void rcu_copy_mutex_unlock(void)
 155 {
 156         int ret;
 157
 158         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 159         if (ret) {
 160                 perror("Error in pthread mutex unlock");
 161                 exit(-1);
 162         }
 163 }
 164
 165 /*
 166  * malloc/free are reusing memory areas too quickly, which does not let us
 167  * test races appropriately. Use a large circular array for allocations.
 168  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 169  */
 170 #define ARRAY_SIZE (1048576 * nr_writers)
 171 #define ARRAY_POISON 0xDEADBEEF
 172 static int array_index;
 173 static struct test_array *test_array;
 174
 175 static struct test_array *test_array_alloc(void)
 176 {
 177         struct test_array *ret;
 178         int index;
 179
 180         rcu_copy_mutex_lock();
 181         index = array_index % ARRAY_SIZE;
 182         assert(test_array[index].a == ARRAY_POISON ||
 183                 test_array[index].a == 0);
 184         ret = &test_array[index];
 185         array_index++;
 186         if (array_index == ARRAY_SIZE)
 187                 array_index = 0;
 188         rcu_copy_mutex_unlock();
 189         return ret;
 190 }
 191
 192 static void test_array_free(struct test_array *ptr)
 193 {
 194         if (!ptr)
 195                 return;
 196         rcu_copy_mutex_lock();
 197         ptr->a = ARRAY_POISON;
 198         rcu_copy_mutex_unlock();
 199 }
 200
 201 void *thr_reader(void *_count)
 202 {
 203         unsigned long long *count = _count;
 204         struct test_array *local_ptr;
 205
 206         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 207                         "reader", pthread_self(), (unsigned long)gettid());
 208
 209         set_affinity();
 210
 211         rcu_register_thread();
 212
 213         while (!test_go)
 214         {
 215         }
 216         smp_mb();
 217
 218         for (;;) {
 219                 rcu_read_lock();
 220                 local_ptr = rcu_dereference(test_rcu_pointer);
 221                 debug_yield_read();
 222                 if (local_ptr)
 223                         assert(local_ptr->a == 8);
 224                 if (unlikely(rduration))
 225                         loop_sleep(rduration);
 226                 rcu_read_unlock();
 227                 nr_reads++;
 228                 if (unlikely(!test_duration_read()))
 229                         break;
 230         }
 231
 232         rcu_unregister_thread();
 233
 234         *count = nr_reads;
 235         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 236                         "reader", pthread_self(), (unsigned long)gettid());
 237         return ((void*)1);
 238
 239 }
 240
 241 void *thr_writer(void *_count)
 242 {
 243         unsigned long long *count = _count;
 244         struct test_array *new, *old;
 245
 246         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 247                         "writer", pthread_self(), (unsigned long)gettid());
 248
 249         set_affinity();
 250
 251         while (!test_go)
 252         {
 253         }
 254         smp_mb();
 255
 256         for (;;) {
 257                 new = test_array_alloc();
 258                 new->a = 8;
 259                 rcu_copy_mutex_lock();
 260                 old = test_rcu_pointer;
 261                 rcu_assign_pointer(test_rcu_pointer, new);
 262                 rcu_copy_mutex_unlock();
 263                 synchronize_rcu();
 264                 if (old)
 265                         old->a = 0;
 266                 test_array_free(old);
 267                 nr_writes++;
 268                 if (unlikely(!test_duration_write()))
 269                         break;
 270                 if (unlikely(wdelay))
 271                         loop_sleep(wdelay);
 272         }
 273
 274         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 275                         "writer", pthread_self(), (unsigned long)gettid());
 276         *count = nr_writes;
 277         return ((void*)2);
 278 }
 279
 280 void show_usage(int argc, char **argv)
 281 {
 282         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 283 #ifdef DEBUG_YIELD
 284         printf(" [-r] [-w] (yield reader and/or writer)");
 285 #endif
 286         printf(" [-d delay] (writer period (us))");
 287         printf(" [-c duration] (reader C.S. duration (in loops))");
 288         printf(" [-v] (verbose output)");
 289         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 290         printf("\n");
 291 }
 292
 293 int main(int argc, char **argv)
 294 {
 295         int err;
 296         pthread_t *tid_reader, *tid_writer;
 297         void *tret;
 298         unsigned long long *count_reader, *count_writer;
 299         unsigned long long tot_reads = 0, tot_writes = 0;
 300         int i, a;
 301
 302         if (argc < 4) {
 303                 show_usage(argc, argv);
 304                 return -1;
 305         }
 306
 307         err = sscanf(argv[1], "%u", &nr_readers);
 308         if (err != 1) {
 309                 show_usage(argc, argv);
 310                 return -1;
 311         }
 312
 313         err = sscanf(argv[2], "%u", &nr_writers);
 314         if (err != 1) {
 315                 show_usage(argc, argv);
 316                 return -1;
 317         }
 318
 319         err = sscanf(argv[3], "%lu", &duration);
 320         if (err != 1) {
 321                 show_usage(argc, argv);
 322                 return -1;
 323         }
 324
 325         for (i = 4; i < argc; i++) {
 326                 if (argv[i][0] != '-')
 327                         continue;
 328                 switch (argv[i][1]) {
 329 #ifdef DEBUG_YIELD
 330                 case 'r':
 331                         yield_active |= YIELD_READ;
 332                         break;
 333                 case 'w':
 334                         yield_active |= YIELD_WRITE;
 335                         break;
 336 #endif
 337                 case 'a':
 338                         if (argc < i + 2) {
 339                                 show_usage(argc, argv);
 340                                 return -1;
 341                         }
 342                         a = atoi(argv[++i]);
 343                         cpu_affinities[next_aff++] = a;
 344                         use_affinity = 1;
 345                         printf_verbose("Adding CPU %d affinity\n", a);
 346                         break;
 347                 case 'c':
 348                         if (argc < i + 2) {
 349                                 show_usage(argc, argv);
 350                                 return -1;
 351                         }
 352                         rduration = atol(argv[++i]);
 353                         break;
 354                 case 'd':
 355                         if (argc < i + 2) {
 356                                 show_usage(argc, argv);
 357                                 return -1;
 358                         }
 359                         wdelay = atol(argv[++i]);
 360                         break;
 361                 case 'v':
 362                         verbose_mode = 1;
 363                         break;
 364                 }
 365         }
 366
 367         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 368                 duration, nr_readers, nr_writers);
 369         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 370         printf_verbose("Reader duration : %lu loops.\n", rduration);
 371         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 372                         "main", pthread_self(), (unsigned long)gettid());
 373
 374         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 375         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 376         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 377         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 378         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 379
 380         next_aff = 0;
 381
 382         for (i = 0; i < nr_readers; i++) {
 383                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 384                                      &count_reader[i]);
 385                 if (err != 0)
 386                         exit(1);
 387         }
 388         for (i = 0; i < nr_writers; i++) {
 389                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 390                                      &count_writer[i]);
 391                 if (err != 0)
 392                         exit(1);
 393         }
 394
 395         smp_mb();
 396
 397         test_go = 1;
 398
 399         sleep(duration);
 400
 401         test_stop = 1;
 402
 403         for (i = 0; i < nr_readers; i++) {
 404                 err = pthread_join(tid_reader[i], &tret);
 405                 if (err != 0)
 406                         exit(1);
 407                 tot_reads += count_reader[i];
 408         }
 409         for (i = 0; i < nr_writers; i++) {
 410                 err = pthread_join(tid_writer[i], &tret);
 411                 if (err != 0)
 412                         exit(1);
 413                 tot_writes += count_writer[i];
 414         }
 415
 416         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 417                tot_writes);
 418         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 419                 "nr_writers %3u "
 420                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 421                 argv[0], duration, nr_readers, rduration,
 422                 nr_writers, wdelay, tot_reads, tot_writes,
 423                 tot_reads + tot_writes);
 424         test_array_free(test_rcu_pointer);
 425         free(test_array);
 426         free(tid_reader);
 427         free(tid_writer);
 428         free(count_reader);
 429         free(count_writer);
 430         return 0;
 431 }