tests/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 "../config.h"
  25 #include <stdio.h>
  26 #include <pthread.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <sys/types.h>
  30 #include <sys/wait.h>
  31 #include <unistd.h>
  32 #include <stdio.h>
  33 #include <assert.h>
  34 #include <sys/syscall.h>
  35 #include <sched.h>
  36 #include <errno.h>
  37
  38 #include <urcu/arch.h>
  39
  40 /* hardcoded number of CPUs */
  41 #define NR_CPUS 16384
  42
  43 #if defined(_syscall0)
  44 _syscall0(pid_t, gettid)
  45 #elif defined(__NR_gettid)
  46 static inline pid_t gettid(void)
  47 {
  48         return syscall(__NR_gettid);
  49 }
  50 #else
  51 #warning "use pid as tid"
  52 static inline pid_t gettid(void)
  53 {
  54         return getpid();
  55 }
  56 #endif
  57
  58 #ifndef DYNAMIC_LINK_TEST
  59 #define _LGPL_SOURCE
  60 #else
  61 #define debug_yield_read()
  62 #endif
  63 #include <urcu.h>
  64
  65 struct test_array {
  66         int a;
  67 };
  68
  69 static volatile int test_go, test_stop;
  70
  71 static unsigned long wdelay;
  72
  73 static struct test_array *test_rcu_pointer;
  74
  75 static unsigned long duration;
  76
  77 /* read-side C.S. duration, in loops */
  78 static unsigned long rduration;
  79
  80 static inline void loop_sleep(unsigned long l)
  81 {
  82         while(l-- != 0)
  83                 cpu_relax();
  84 }
  85
  86 static int verbose_mode;
  87
  88 #define printf_verbose(fmt, args...)            \
  89         do {                                    \
  90                 if (verbose_mode)               \
  91                         printf(fmt, args);      \
  92         } while (0)
  93
  94 static unsigned int cpu_affinities[NR_CPUS];
  95 static unsigned int next_aff = 0;
  96 static int use_affinity = 0;
  97
  98 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
  99
 100 #ifndef HAVE_CPU_SET_T
 101 typedef unsigned long cpu_set_t;
 102 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
 103 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
 104 #endif
 105
 106 static void set_affinity(void)
 107 {
 108         cpu_set_t mask;
 109         int cpu;
 110         int ret;
 111
 112         if (!use_affinity)
 113                 return;
 114
 115 #if HAVE_SCHED_SETAFFINITY
 116         ret = pthread_mutex_lock(&affinity_mutex);
 117         if (ret) {
 118                 perror("Error in pthread mutex lock");
 119                 exit(-1);
 120         }
 121         cpu = cpu_affinities[next_aff++];
 122         ret = pthread_mutex_unlock(&affinity_mutex);
 123         if (ret) {
 124                 perror("Error in pthread mutex unlock");
 125                 exit(-1);
 126         }
 127
 128         CPU_ZERO(&mask);
 129         CPU_SET(cpu, &mask);
 130 #if SCHED_SETAFFINITY_ARGS == 2
 131         sched_setaffinity(0, &mask);
 132 #else
 133         sched_setaffinity(0, sizeof(mask), &mask);
 134 #endif
 135 #endif /* HAVE_SCHED_SETAFFINITY */
 136 }
 137
 138 /*
 139  * returns 0 if test should end.
 140  */
 141 static int test_duration_write(void)
 142 {
 143         return !test_stop;
 144 }
 145
 146 static int test_duration_read(void)
 147 {
 148         return !test_stop;
 149 }
 150
 151 static unsigned long long __thread nr_writes;
 152 static unsigned long long __thread nr_reads;
 153
 154 static unsigned int nr_readers;
 155 static unsigned int nr_writers;
 156
 157 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 158
 159 void rcu_copy_mutex_lock(void)
 160 {
 161         int ret;
 162         ret = pthread_mutex_lock(&rcu_copy_mutex);
 163         if (ret) {
 164                 perror("Error in pthread mutex lock");
 165                 exit(-1);
 166         }
 167 }
 168
 169 void rcu_copy_mutex_unlock(void)
 170 {
 171         int ret;
 172
 173         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 174         if (ret) {
 175                 perror("Error in pthread mutex unlock");
 176                 exit(-1);
 177         }
 178 }
 179
 180 /*
 181  * malloc/free are reusing memory areas too quickly, which does not let us
 182  * test races appropriately. Use a large circular array for allocations.
 183  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 184  */
 185 #define ARRAY_SIZE (1048576 * nr_writers)
 186 #define ARRAY_POISON 0xDEADBEEF
 187 static int array_index;
 188 static struct test_array *test_array;
 189
 190 static struct test_array *test_array_alloc(void)
 191 {
 192         struct test_array *ret;
 193         int index;
 194
 195         rcu_copy_mutex_lock();
 196         index = array_index % ARRAY_SIZE;
 197         assert(test_array[index].a == ARRAY_POISON ||
 198                 test_array[index].a == 0);
 199         ret = &test_array[index];
 200         array_index++;
 201         if (array_index == ARRAY_SIZE)
 202                 array_index = 0;
 203         rcu_copy_mutex_unlock();
 204         return ret;
 205 }
 206
 207 static void test_array_free(struct test_array *ptr)
 208 {
 209         if (!ptr)
 210                 return;
 211         rcu_copy_mutex_lock();
 212         ptr->a = ARRAY_POISON;
 213         rcu_copy_mutex_unlock();
 214 }
 215
 216 void *thr_reader(void *_count)
 217 {
 218         unsigned long long *count = _count;
 219         struct test_array *local_ptr;
 220
 221         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 222                         "reader", pthread_self(), (unsigned long)gettid());
 223
 224         set_affinity();
 225
 226         rcu_register_thread();
 227
 228         while (!test_go)
 229         {
 230         }
 231         smp_mb();
 232
 233         for (;;) {
 234                 rcu_read_lock();
 235                 local_ptr = rcu_dereference(test_rcu_pointer);
 236                 debug_yield_read();
 237                 if (local_ptr)
 238                         assert(local_ptr->a == 8);
 239                 if (unlikely(rduration))
 240                         loop_sleep(rduration);
 241                 rcu_read_unlock();
 242                 nr_reads++;
 243                 if (unlikely(!test_duration_read()))
 244                         break;
 245         }
 246
 247         rcu_unregister_thread();
 248
 249         *count = nr_reads;
 250         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 251                         "reader", pthread_self(), (unsigned long)gettid());
 252         return ((void*)1);
 253
 254 }
 255
 256 void *thr_writer(void *_count)
 257 {
 258         unsigned long long *count = _count;
 259         struct test_array *new, *old;
 260
 261         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 262                         "writer", pthread_self(), (unsigned long)gettid());
 263
 264         set_affinity();
 265
 266         while (!test_go)
 267         {
 268         }
 269         smp_mb();
 270
 271         for (;;) {
 272                 new = test_array_alloc();
 273                 new->a = 8;
 274                 old = rcu_xchg_pointer(&test_rcu_pointer, new);
 275                 synchronize_rcu();
 276                 if (old)
 277                         old->a = 0;
 278                 test_array_free(old);
 279                 nr_writes++;
 280                 if (unlikely(!test_duration_write()))
 281                         break;
 282                 if (unlikely(wdelay))
 283                         loop_sleep(wdelay);
 284         }
 285
 286         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 287                         "writer", pthread_self(), (unsigned long)gettid());
 288         *count = nr_writes;
 289         return ((void*)2);
 290 }
 291
 292 void show_usage(int argc, char **argv)
 293 {
 294         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 295 #ifdef DEBUG_YIELD
 296         printf(" [-r] [-w] (yield reader and/or writer)");
 297 #endif
 298         printf(" [-d delay] (writer period (us))");
 299         printf(" [-c duration] (reader C.S. duration (in loops))");
 300         printf(" [-v] (verbose output)");
 301         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 302         printf("\n");
 303 }
 304
 305 int main(int argc, char **argv)
 306 {
 307         int err;
 308         pthread_t *tid_reader, *tid_writer;
 309         void *tret;
 310         unsigned long long *count_reader, *count_writer;
 311         unsigned long long tot_reads = 0, tot_writes = 0;
 312         int i, a;
 313
 314         if (argc < 4) {
 315                 show_usage(argc, argv);
 316                 return -1;
 317         }
 318
 319         err = sscanf(argv[1], "%u", &nr_readers);
 320         if (err != 1) {
 321                 show_usage(argc, argv);
 322                 return -1;
 323         }
 324
 325         err = sscanf(argv[2], "%u", &nr_writers);
 326         if (err != 1) {
 327                 show_usage(argc, argv);
 328                 return -1;
 329         }
 330
 331         err = sscanf(argv[3], "%lu", &duration);
 332         if (err != 1) {
 333                 show_usage(argc, argv);
 334                 return -1;
 335         }
 336
 337         for (i = 4; i < argc; i++) {
 338                 if (argv[i][0] != '-')
 339                         continue;
 340                 switch (argv[i][1]) {
 341 #ifdef DEBUG_YIELD
 342                 case 'r':
 343                         yield_active |= YIELD_READ;
 344                         break;
 345                 case 'w':
 346                         yield_active |= YIELD_WRITE;
 347                         break;
 348 #endif
 349                 case 'a':
 350                         if (argc < i + 2) {
 351                                 show_usage(argc, argv);
 352                                 return -1;
 353                         }
 354                         a = atoi(argv[++i]);
 355                         cpu_affinities[next_aff++] = a;
 356                         use_affinity = 1;
 357                         printf_verbose("Adding CPU %d affinity\n", a);
 358                         break;
 359                 case 'c':
 360                         if (argc < i + 2) {
 361                                 show_usage(argc, argv);
 362                                 return -1;
 363                         }
 364                         rduration = atol(argv[++i]);
 365                         break;
 366                 case 'd':
 367                         if (argc < i + 2) {
 368                                 show_usage(argc, argv);
 369                                 return -1;
 370                         }
 371                         wdelay = atol(argv[++i]);
 372                         break;
 373                 case 'v':
 374                         verbose_mode = 1;
 375                         break;
 376                 }
 377         }
 378
 379         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 380                 duration, nr_readers, nr_writers);
 381         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 382         printf_verbose("Reader duration : %lu loops.\n", rduration);
 383         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 384                         "main", pthread_self(), (unsigned long)gettid());
 385
 386         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 387         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 388         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 389         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 390         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 391
 392         next_aff = 0;
 393
 394         for (i = 0; i < nr_readers; i++) {
 395                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 396                                      &count_reader[i]);
 397                 if (err != 0)
 398                         exit(1);
 399         }
 400         for (i = 0; i < nr_writers; i++) {
 401                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 402                                      &count_writer[i]);
 403                 if (err != 0)
 404                         exit(1);
 405         }
 406
 407         smp_mb();
 408
 409         test_go = 1;
 410
 411         sleep(duration);
 412
 413         test_stop = 1;
 414
 415         for (i = 0; i < nr_readers; i++) {
 416                 err = pthread_join(tid_reader[i], &tret);
 417                 if (err != 0)
 418                         exit(1);
 419                 tot_reads += count_reader[i];
 420         }
 421         for (i = 0; i < nr_writers; i++) {
 422                 err = pthread_join(tid_writer[i], &tret);
 423                 if (err != 0)
 424                         exit(1);
 425                 tot_writes += count_writer[i];
 426         }
 427
 428         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 429                tot_writes);
 430         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 431                 "nr_writers %3u "
 432                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 433                 argv[0], duration, nr_readers, rduration,
 434                 nr_writers, wdelay, tot_reads, tot_writes,
 435                 tot_reads + tot_writes);
 436         test_array_free(test_rcu_pointer);
 437         free(test_array);
 438         free(tid_reader);
 439         free(tid_writer);
 440         free(count_reader);
 441         free(count_writer);
 442         return 0;
 443 }