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