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