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