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 <sched.h>
  35 #include <errno.h>
  36
  37 #include <urcu/arch.h>
  38 #include <urcu/tls-compat.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 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 #ifndef HAVE_CPU_SET_T
 108 typedef unsigned long cpu_set_t;
 109 # define CPU_ZERO(cpuset) do { *(cpuset) = 0; } while(0)
 110 # define CPU_SET(cpu, cpuset) do { *(cpuset) |= (1UL << (cpu)); } while(0)
 111 #endif
 112
 113 static void set_affinity(void)
 114 {
 115 #if HAVE_SCHED_SETAFFINITY
 116         cpu_set_t mask;
 117         int cpu, ret;
 118 #endif /* HAVE_SCHED_SETAFFINITY */
 119
 120         if (!use_affinity)
 121                 return;
 122
 123 #if HAVE_SCHED_SETAFFINITY
 124         ret = pthread_mutex_lock(&affinity_mutex);
 125         if (ret) {
 126                 perror("Error in pthread mutex lock");
 127                 exit(-1);
 128         }
 129         cpu = cpu_affinities[next_aff++];
 130         ret = pthread_mutex_unlock(&affinity_mutex);
 131         if (ret) {
 132                 perror("Error in pthread mutex unlock");
 133                 exit(-1);
 134         }
 135
 136         CPU_ZERO(&mask);
 137         CPU_SET(cpu, &mask);
 138 #if SCHED_SETAFFINITY_ARGS == 2
 139         sched_setaffinity(0, &mask);
 140 #else
 141         sched_setaffinity(0, sizeof(mask), &mask);
 142 #endif
 143 #endif /* HAVE_SCHED_SETAFFINITY */
 144 }
 145
 146 /*
 147  * returns 0 if test should end.
 148  */
 149 static int test_duration_write(void)
 150 {
 151         return !test_stop;
 152 }
 153
 154 static int test_duration_read(void)
 155 {
 156         return !test_stop;
 157 }
 158
 159 static DEFINE_URCU_TLS(unsigned long long, nr_writes);
 160 static DEFINE_URCU_TLS(unsigned long long, nr_reads);
 161
 162 static unsigned int nr_readers;
 163 static unsigned int nr_writers;
 164
 165 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 166
 167 void rcu_copy_mutex_lock(void)
 168 {
 169         int ret;
 170         ret = pthread_mutex_lock(&rcu_copy_mutex);
 171         if (ret) {
 172                 perror("Error in pthread mutex lock");
 173                 exit(-1);
 174         }
 175 }
 176
 177 void rcu_copy_mutex_unlock(void)
 178 {
 179         int ret;
 180
 181         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 182         if (ret) {
 183                 perror("Error in pthread mutex unlock");
 184                 exit(-1);
 185         }
 186 }
 187
 188 /*
 189  * malloc/free are reusing memory areas too quickly, which does not let us
 190  * test races appropriately. Use a large circular array for allocations.
 191  * ARRAY_SIZE is larger than nr_writers, and we keep the mutex across
 192  * both alloc and free, which insures we never run over our tail.
 193  */
 194 #define ARRAY_SIZE (1048576 * nr_writers)
 195 #define ARRAY_POISON 0xDEADBEEF
 196 static int array_index;
 197 static struct test_array *test_array;
 198
 199 static struct test_array *test_array_alloc(void)
 200 {
 201         struct test_array *ret;
 202         int index;
 203
 204         index = array_index % ARRAY_SIZE;
 205         assert(test_array[index].a == ARRAY_POISON ||
 206                 test_array[index].a == 0);
 207         ret = &test_array[index];
 208         array_index++;
 209         if (array_index == ARRAY_SIZE)
 210                 array_index = 0;
 211         return ret;
 212 }
 213
 214 static void test_array_free(struct test_array *ptr)
 215 {
 216         if (!ptr)
 217                 return;
 218         ptr->a = ARRAY_POISON;
 219 }
 220
 221 void *thr_reader(void *_count)
 222 {
 223         unsigned long long *count = _count;
 224         struct test_array *local_ptr;
 225
 226         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 227                         "reader", pthread_self(), (unsigned long)gettid());
 228
 229         set_affinity();
 230
 231         rcu_register_thread();
 232
 233         while (!test_go)
 234         {
 235         }
 236         cmm_smp_mb();
 237
 238         for (;;) {
 239                 rcu_read_lock();
 240                 local_ptr = rcu_dereference(test_rcu_pointer);
 241                 debug_yield_read();
 242                 if (local_ptr)
 243                         assert(local_ptr->a == 8);
 244                 if (caa_unlikely(rduration))
 245                         loop_sleep(rduration);
 246                 rcu_read_unlock();
 247                 URCU_TLS(nr_reads)++;
 248                 if (caa_unlikely(!test_duration_read()))
 249                         break;
 250         }
 251
 252         rcu_unregister_thread();
 253
 254         /* test extra thread registration */
 255         rcu_register_thread();
 256         rcu_unregister_thread();
 257
 258         *count = URCU_TLS(nr_reads);
 259         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 260                         "reader", pthread_self(), (unsigned long)gettid());
 261         return ((void*)1);
 262
 263 }
 264
 265 void *thr_writer(void *_count)
 266 {
 267         unsigned long long *count = _count;
 268         struct test_array *new, *old;
 269
 270         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 271                         "writer", pthread_self(), (unsigned long)gettid());
 272
 273         set_affinity();
 274
 275         while (!test_go)
 276         {
 277         }
 278         cmm_smp_mb();
 279
 280         for (;;) {
 281                 rcu_copy_mutex_lock();
 282                 new = test_array_alloc();
 283                 new->a = 8;
 284                 old = rcu_xchg_pointer(&test_rcu_pointer, new);
 285                 if (caa_unlikely(wduration))
 286                         loop_sleep(wduration);
 287                 synchronize_rcu();
 288                 if (old)
 289                         old->a = 0;
 290                 test_array_free(old);
 291                 rcu_copy_mutex_unlock();
 292                 URCU_TLS(nr_writes)++;
 293                 if (caa_unlikely(!test_duration_write()))
 294                         break;
 295                 if (caa_unlikely(wdelay))
 296                         loop_sleep(wdelay);
 297         }
 298
 299         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 300                         "writer", pthread_self(), (unsigned long)gettid());
 301         *count = URCU_TLS(nr_writes);
 302         return ((void*)2);
 303 }
 304
 305 void show_usage(int argc, char **argv)
 306 {
 307         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 308 #ifdef DEBUG_YIELD
 309         printf(" [-r] [-w] (yield reader and/or writer)");
 310 #endif
 311         printf(" [-d delay] (writer period (us))");
 312         printf(" [-c duration] (reader C.S. duration (in loops))");
 313         printf(" [-e duration] (writer C.S. duration (in loops))");
 314         printf(" [-v] (verbose output)");
 315         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 316         printf("\n");
 317 }
 318
 319 int main(int argc, char **argv)
 320 {
 321         int err;
 322         pthread_t *tid_reader, *tid_writer;
 323         void *tret;
 324         unsigned long long *count_reader, *count_writer;
 325         unsigned long long tot_reads = 0, tot_writes = 0;
 326         int i, a;
 327
 328         if (argc < 4) {
 329                 show_usage(argc, argv);
 330                 return -1;
 331         }
 332
 333         err = sscanf(argv[1], "%u", &nr_readers);
 334         if (err != 1) {
 335                 show_usage(argc, argv);
 336                 return -1;
 337         }
 338
 339         err = sscanf(argv[2], "%u", &nr_writers);
 340         if (err != 1) {
 341                 show_usage(argc, argv);
 342                 return -1;
 343         }
 344
 345         err = sscanf(argv[3], "%lu", &duration);
 346         if (err != 1) {
 347                 show_usage(argc, argv);
 348                 return -1;
 349         }
 350
 351         for (i = 4; i < argc; i++) {
 352                 if (argv[i][0] != '-')
 353                         continue;
 354                 switch (argv[i][1]) {
 355 #ifdef DEBUG_YIELD
 356                 case 'r':
 357                         yield_active |= YIELD_READ;
 358                         break;
 359                 case 'w':
 360                         yield_active |= YIELD_WRITE;
 361                         break;
 362 #endif
 363                 case 'a':
 364                         if (argc < i + 2) {
 365                                 show_usage(argc, argv);
 366                                 return -1;
 367                         }
 368                         a = atoi(argv[++i]);
 369                         cpu_affinities[next_aff++] = a;
 370                         use_affinity = 1;
 371                         printf_verbose("Adding CPU %d affinity\n", a);
 372                         break;
 373                 case 'c':
 374                         if (argc < i + 2) {
 375                                 show_usage(argc, argv);
 376                                 return -1;
 377                         }
 378                         rduration = atol(argv[++i]);
 379                         break;
 380                 case 'd':
 381                         if (argc < i + 2) {
 382                                 show_usage(argc, argv);
 383                                 return -1;
 384                         }
 385                         wdelay = atol(argv[++i]);
 386                         break;
 387                 case 'e':
 388                         if (argc < i + 2) {
 389                                 show_usage(argc, argv);
 390                                 return -1;
 391                         }
 392                         wduration = atol(argv[++i]);
 393                         break;
 394                 case 'v':
 395                         verbose_mode = 1;
 396                         break;
 397                 }
 398         }
 399
 400         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 401                 duration, nr_readers, nr_writers);
 402         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 403         printf_verbose("Reader duration : %lu loops.\n", rduration);
 404         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 405                         "main", pthread_self(), (unsigned long)gettid());
 406
 407         test_array = calloc(1, sizeof(*test_array) * ARRAY_SIZE);
 408         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 409         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 410         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 411         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 412
 413         next_aff = 0;
 414
 415         for (i = 0; i < nr_readers; i++) {
 416                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 417                                      &count_reader[i]);
 418                 if (err != 0)
 419                         exit(1);
 420         }
 421         for (i = 0; i < nr_writers; i++) {
 422                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 423                                      &count_writer[i]);
 424                 if (err != 0)
 425                         exit(1);
 426         }
 427
 428         cmm_smp_mb();
 429
 430         test_go = 1;
 431
 432         sleep(duration);
 433
 434         test_stop = 1;
 435
 436         for (i = 0; i < nr_readers; i++) {
 437                 err = pthread_join(tid_reader[i], &tret);
 438                 if (err != 0)
 439                         exit(1);
 440                 tot_reads += count_reader[i];
 441         }
 442         for (i = 0; i < nr_writers; i++) {
 443                 err = pthread_join(tid_writer[i], &tret);
 444                 if (err != 0)
 445                         exit(1);
 446                 tot_writes += count_writer[i];
 447         }
 448
 449         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 450                tot_writes);
 451         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu wdur %6lu "
 452                 "nr_writers %3u "
 453                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 454                 argv[0], duration, nr_readers, rduration, wduration,
 455                 nr_writers, wdelay, tot_reads, tot_writes,
 456                 tot_reads + tot_writes);
 457         test_array_free(test_rcu_pointer);
 458         free(test_array);
 459         free(tid_reader);
 460         free(tid_writer);
 461         free(count_reader);
 462         free(count_writer);
 463         return 0;
 464 }