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@efficios.com>
   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 <errno.h>
  35
  36 #include <urcu/arch.h>
  37 #include <urcu/tls-compat.h>
  38 #include "cpuset.h"
  39
  40 #ifdef __linux__
  41 #include <syscall.h>
  42 #endif
  43
  44 /* hardcoded number of CPUs */
  45 #define NR_CPUS 16384
  46
  47 #if defined(_syscall0)
  48 _syscall0(pid_t, gettid)
  49 #elif defined(__NR_gettid)
  50 static inline pid_t gettid(void)
  51 {
  52         return syscall(__NR_gettid);
  53 }
  54 #else
  55 #warning "use pid as tid"
  56 static inline pid_t gettid(void)
  57 {
  58         return getpid();
  59 }
  60 #endif
  61
  62 #ifndef DYNAMIC_LINK_TEST
  63 #define _LGPL_SOURCE
  64 #else
  65 #define debug_yield_read()
  66 #endif
  67 #include <urcu.h>
  68
  69 struct test_array {
  70         int a;
  71 };
  72
  73 static volatile int test_go, test_stop;
  74
  75 static unsigned long wdelay;
  76
  77 static struct test_array *test_rcu_pointer;
  78
  79 static unsigned long duration;
  80
  81 /* read-side C.S. duration, in loops */
  82 static unsigned long rduration;
  83
  84 /* write-side C.S. duration, in loops */
  85 static unsigned long wduration;
  86
  87 static inline void loop_sleep(unsigned long l)
  88 {
  89         while(l-- != 0)
  90                 caa_cpu_relax();
  91 }
  92
  93 static int verbose_mode;
  94
  95 #define printf_verbose(fmt, args...)            \
  96         do {                                    \
  97                 if (verbose_mode)               \
  98                         printf(fmt, args);      \
  99         } while (0)
 100
 101 static unsigned int cpu_affinities[NR_CPUS];
 102 static unsigned int next_aff = 0;
 103 static int use_affinity = 0;
 104
 105 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 106
 107 static void set_affinity(void)
 108 {
 109         cpu_set_t mask;
 110         int cpu;
 111         int ret;
 112
 113         if (!use_affinity)
 114                 return;
 115
 116 #if HAVE_SCHED_SETAFFINITY
 117         ret = pthread_mutex_lock(&affinity_mutex);
 118         if (ret) {
 119                 perror("Error in pthread mutex lock");
 120                 exit(-1);
 121         }
 122         cpu = cpu_affinities[next_aff++];
 123         ret = pthread_mutex_unlock(&affinity_mutex);
 124         if (ret) {
 125                 perror("Error in pthread mutex unlock");
 126                 exit(-1);
 127         }
 128
 129         CPU_ZERO(&mask);
 130         CPU_SET(cpu, &mask);
 131 #if SCHED_SETAFFINITY_ARGS == 2
 132         sched_setaffinity(0, &mask);
 133 #else
 134         sched_setaffinity(0, sizeof(mask), &mask);
 135 #endif
 136 #endif /* HAVE_SCHED_SETAFFINITY */
 137 }
 138
 139 /*
 140  * returns 0 if test should end.
 141  */
 142 static int test_duration_write(void)
 143 {
 144         return !test_stop;
 145 }
 146
 147 static int test_duration_read(void)
 148 {
 149         return !test_stop;
 150 }
 151
 152 static DEFINE_URCU_TLS(unsigned long long, nr_writes);
 153 static DEFINE_URCU_TLS(unsigned long long, nr_reads);
 154
 155 static unsigned int nr_readers;
 156 static unsigned int nr_writers;
 157
 158 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 159
 160 void rcu_copy_mutex_lock(void)
 161 {
 162         int ret;
 163         ret = pthread_mutex_lock(&rcu_copy_mutex);
 164         if (ret) {
 165                 perror("Error in pthread mutex lock");
 166                 exit(-1);
 167         }
 168 }
 169
 170 void rcu_copy_mutex_unlock(void)
 171 {
 172         int ret;
 173
 174         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 175         if (ret) {
 176                 perror("Error in pthread mutex unlock");
 177                 exit(-1);
 178         }
 179 }
 180
 181 /*
 182  * malloc/free are reusing memory areas too quickly, which does not let us
 183  * test races appropriately. Use a large circular array for allocations.
 184  * ARRAY_SIZE is larger than nr_writers, and we keep the mutex across
 185  * both alloc and free, which insures we never run over our tail.
 186  */
 187 #define ARRAY_SIZE (1048576 * nr_writers)
 188 #define ARRAY_POISON 0xDEADBEEF
 189 static int array_index;
 190 static struct test_array *test_array;
 191
 192 static struct test_array *test_array_alloc(void)
 193 {
 194         struct test_array *ret;
 195         int index;
 196
 197         index = array_index % ARRAY_SIZE;
 198         assert(test_array[index].a == ARRAY_POISON ||
 199                 test_array[index].a == 0);
 200         ret = &test_array[index];
 201         array_index++;
 202         if (array_index == ARRAY_SIZE)
 203                 array_index = 0;
 204         return ret;
 205 }
 206
 207 static void test_array_free(struct test_array *ptr)
 208 {
 209         if (!ptr)
 210                 return;
 211         ptr->a = ARRAY_POISON;
 212 }
 213
 214 void *thr_reader(void *_count)
 215 {
 216         unsigned long long *count = _count;
 217         struct test_array *local_ptr;
 218
 219         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 220                         "reader", (unsigned long) pthread_self(),
 221                         (unsigned long) gettid());
 222
 223         set_affinity();
 224
 225         rcu_register_thread();
 226
 227         while (!test_go)
 228         {
 229         }
 230         cmm_smp_mb();
 231
 232         for (;;) {
 233                 rcu_read_lock();
 234                 local_ptr = rcu_dereference(test_rcu_pointer);
 235                 debug_yield_read();
 236                 if (local_ptr)
 237                         assert(local_ptr->a == 8);
 238                 if (caa_unlikely(rduration))
 239                         loop_sleep(rduration);
 240                 rcu_read_unlock();
 241                 URCU_TLS(nr_reads)++;
 242                 if (caa_unlikely(!test_duration_read()))
 243                         break;
 244         }
 245
 246         rcu_unregister_thread();
 247
 248         /* test extra thread registration */
 249         rcu_register_thread();
 250         rcu_unregister_thread();
 251
 252         *count = URCU_TLS(nr_reads);
 253         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 254                         "reader", (unsigned long) pthread_self(),
 255                         (unsigned long) gettid());
 256         return ((void*)1);
 257
 258 }
 259
 260 void *thr_writer(void *_count)
 261 {
 262         unsigned long long *count = _count;
 263         struct test_array *new, *old;
 264
 265         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 266                         "writer", (unsigned long) pthread_self(),
 267                         (unsigned long) gettid());
 268
 269         set_affinity();
 270
 271         while (!test_go)
 272         {
 273         }
 274         cmm_smp_mb();
 275
 276         for (;;) {
 277                 rcu_copy_mutex_lock();
 278                 new = test_array_alloc();
 279                 new->a = 8;
 280                 old = rcu_xchg_pointer(&test_rcu_pointer, new);
 281                 if (caa_unlikely(wduration))
 282                         loop_sleep(wduration);
 283                 synchronize_rcu();
 284                 if (old)
 285                         old->a = 0;
 286                 test_array_free(old);
 287                 rcu_copy_mutex_unlock();
 288                 URCU_TLS(nr_writes)++;
 289                 if (caa_unlikely(!test_duration_write()))
 290                         break;
 291                 if (caa_unlikely(wdelay))
 292                         loop_sleep(wdelay);
 293         }
 294
 295         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 296                         "writer", (unsigned long) pthread_self(),
 297                         (unsigned long) gettid());
 298         *count = URCU_TLS(nr_writes);
 299         return ((void*)2);
 300 }
 301
 302 void show_usage(int argc, char **argv)
 303 {
 304         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 305 #ifdef DEBUG_YIELD
 306         printf(" [-r] [-w] (yield reader and/or writer)");
 307 #endif
 308         printf(" [-d delay] (writer period (us))");
 309         printf(" [-c duration] (reader C.S. duration (in loops))");
 310         printf(" [-e duration] (writer C.S. duration (in loops))");
 311         printf(" [-v] (verbose output)");
 312         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 313         printf("\n");
 314 }
 315
 316 int main(int argc, char **argv)
 317 {
 318         int err;
 319         pthread_t *tid_reader, *tid_writer;
 320         void *tret;
 321         unsigned long long *count_reader, *count_writer;
 322         unsigned long long tot_reads = 0, tot_writes = 0;
 323         int i, a;
 324
 325         if (argc < 4) {
 326                 show_usage(argc, argv);
 327                 return -1;
 328         }
 329
 330         err = sscanf(argv[1], "%u", &nr_readers);
 331         if (err != 1) {
 332                 show_usage(argc, argv);
 333                 return -1;
 334         }
 335
 336         err = sscanf(argv[2], "%u", &nr_writers);
 337         if (err != 1) {
 338                 show_usage(argc, argv);
 339                 return -1;
 340         }
 341
 342         err = sscanf(argv[3], "%lu", &duration);
 343         if (err != 1) {
 344                 show_usage(argc, argv);
 345                 return -1;
 346         }
 347
 348         for (i = 4; i < argc; i++) {
 349                 if (argv[i][0] != '-')
 350                         continue;
 351                 switch (argv[i][1]) {
 352 #ifdef DEBUG_YIELD
 353                 case 'r':
 354                         yield_active |= YIELD_READ;
 355                         break;
 356                 case 'w':
 357                         yield_active |= YIELD_WRITE;
 358                         break;
 359 #endif
 360                 case 'a':
 361                         if (argc < i + 2) {
 362                                 show_usage(argc, argv);
 363                                 return -1;
 364                         }
 365                         a = atoi(argv[++i]);
 366                         cpu_affinities[next_aff++] = a;
 367                         use_affinity = 1;
 368                         printf_verbose("Adding CPU %d affinity\n", a);
 369                         break;
 370                 case 'c':
 371                         if (argc < i + 2) {
 372                                 show_usage(argc, argv);
 373                                 return -1;
 374                         }
 375                         rduration = atol(argv[++i]);
 376                         break;
 377                 case 'd':
 378                         if (argc < i + 2) {
 379                                 show_usage(argc, argv);
 380                                 return -1;
 381                         }
 382                         wdelay = atol(argv[++i]);
 383                         break;
 384                 case 'e':
 385                         if (argc < i + 2) {
 386                                 show_usage(argc, argv);
 387                                 return -1;
 388                         }
 389                         wduration = atol(argv[++i]);
 390                         break;
 391                 case 'v':
 392                         verbose_mode = 1;
 393                         break;
 394                 }
 395         }
 396
 397         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 398                 duration, nr_readers, nr_writers);
 399         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 400         printf_verbose("Reader duration : %lu loops.\n", rduration);
 401         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 402                         "main", (unsigned long) pthread_self(),
 403                         (unsigned long)gettid());
 404
 405         test_array = calloc(1, sizeof(*test_array) * ARRAY_SIZE);
 406         tid_reader = calloc(nr_readers, sizeof(*tid_reader));
 407         tid_writer = calloc(nr_writers, sizeof(*tid_writer));
 408         count_reader = calloc(nr_readers, sizeof(*count_reader));
 409         count_writer = calloc(nr_writers, sizeof(*count_writer));
 410
 411         next_aff = 0;
 412
 413         for (i = 0; i < nr_readers; i++) {
 414                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 415                                      &count_reader[i]);
 416                 if (err != 0)
 417                         exit(1);
 418         }
 419         for (i = 0; i < nr_writers; i++) {
 420                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 421                                      &count_writer[i]);
 422                 if (err != 0)
 423                         exit(1);
 424         }
 425
 426         cmm_smp_mb();
 427
 428         test_go = 1;
 429
 430         sleep(duration);
 431
 432         test_stop = 1;
 433
 434         for (i = 0; i < nr_readers; i++) {
 435                 err = pthread_join(tid_reader[i], &tret);
 436                 if (err != 0)
 437                         exit(1);
 438                 tot_reads += count_reader[i];
 439         }
 440         for (i = 0; i < nr_writers; i++) {
 441                 err = pthread_join(tid_writer[i], &tret);
 442                 if (err != 0)
 443                         exit(1);
 444                 tot_writes += count_writer[i];
 445         }
 446
 447         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 448                tot_writes);
 449         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu wdur %6lu "
 450                 "nr_writers %3u "
 451                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 452                 argv[0], duration, nr_readers, rduration, wduration,
 453                 nr_writers, wdelay, tot_reads, tot_writes,
 454                 tot_reads + tot_writes);
 455         test_array_free(test_rcu_pointer);
 456         free(test_array);
 457         free(tid_reader);
 458         free(tid_writer);
 459         free(count_reader);
 460         free(count_writer);
 461         return 0;
 462 }