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 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         *count = URCU_TLS(nr_reads);
 249         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 250                         "reader", (unsigned long) pthread_self(),
 251                         (unsigned long) gettid());
 252         return ((void*)1);
 253
 254 }
 255
 256 void *thr_writer(void *_count)
 257 {
 258         unsigned long long *count = _count;
 259         struct test_array *new, *old;
 260
 261         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 262                         "writer", (unsigned long) pthread_self(),
 263                         (unsigned long) gettid());
 264
 265         set_affinity();
 266
 267         while (!test_go)
 268         {
 269         }
 270         cmm_smp_mb();
 271
 272         for (;;) {
 273                 rcu_copy_mutex_lock();
 274                 new = test_array_alloc();
 275                 new->a = 8;
 276                 old = test_rcu_pointer;
 277                 rcu_assign_pointer(test_rcu_pointer, new);
 278                 if (caa_unlikely(wduration))
 279                         loop_sleep(wduration);
 280                 synchronize_rcu();
 281                 if (old)
 282                         old->a = 0;
 283                 test_array_free(old);
 284                 rcu_copy_mutex_unlock();
 285                 URCU_TLS(nr_writes)++;
 286                 if (caa_unlikely(!test_duration_write()))
 287                         break;
 288                 if (caa_unlikely(wdelay))
 289                         loop_sleep(wdelay);
 290         }
 291
 292         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 293                         "writer", (unsigned long) pthread_self(),
 294                         (unsigned long) gettid());
 295         *count = URCU_TLS(nr_writes);
 296         return ((void*)2);
 297 }
 298
 299 void show_usage(int argc, char **argv)
 300 {
 301         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 302 #ifdef DEBUG_YIELD
 303         printf(" [-r] [-w] (yield reader and/or writer)");
 304 #endif
 305         printf(" [-d delay] (writer period (us))");
 306         printf(" [-c duration] (reader C.S. duration (in loops))");
 307         printf(" [-e duration] (writer C.S. duration (in loops))");
 308         printf(" [-v] (verbose output)");
 309         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 310         printf("\n");
 311 }
 312
 313 int main(int argc, char **argv)
 314 {
 315         int err;
 316         pthread_t *tid_reader, *tid_writer;
 317         void *tret;
 318         unsigned long long *count_reader, *count_writer;
 319         unsigned long long tot_reads = 0, tot_writes = 0;
 320         int i, a;
 321
 322         if (argc < 4) {
 323                 show_usage(argc, argv);
 324                 return -1;
 325         }
 326
 327         err = sscanf(argv[1], "%u", &nr_readers);
 328         if (err != 1) {
 329                 show_usage(argc, argv);
 330                 return -1;
 331         }
 332
 333         err = sscanf(argv[2], "%u", &nr_writers);
 334         if (err != 1) {
 335                 show_usage(argc, argv);
 336                 return -1;
 337         }
 338
 339         err = sscanf(argv[3], "%lu", &duration);
 340         if (err != 1) {
 341                 show_usage(argc, argv);
 342                 return -1;
 343         }
 344
 345         for (i = 4; i < argc; i++) {
 346                 if (argv[i][0] != '-')
 347                         continue;
 348                 switch (argv[i][1]) {
 349 #ifdef DEBUG_YIELD
 350                 case 'r':
 351                         yield_active |= YIELD_READ;
 352                         break;
 353                 case 'w':
 354                         yield_active |= YIELD_WRITE;
 355                         break;
 356 #endif
 357                 case 'a':
 358                         if (argc < i + 2) {
 359                                 show_usage(argc, argv);
 360                                 return -1;
 361                         }
 362                         a = atoi(argv[++i]);
 363                         cpu_affinities[next_aff++] = a;
 364                         use_affinity = 1;
 365                         printf_verbose("Adding CPU %d affinity\n", a);
 366                         break;
 367                 case 'c':
 368                         if (argc < i + 2) {
 369                                 show_usage(argc, argv);
 370                                 return -1;
 371                         }
 372                         rduration = atol(argv[++i]);
 373                         break;
 374                 case 'd':
 375                         if (argc < i + 2) {
 376                                 show_usage(argc, argv);
 377                                 return -1;
 378                         }
 379                         wdelay = atol(argv[++i]);
 380                         break;
 381                 case 'e':
 382                         if (argc < i + 2) {
 383                                 show_usage(argc, argv);
 384                                 return -1;
 385                         }
 386                         wduration = atol(argv[++i]);
 387                         break;
 388                 case 'v':
 389                         verbose_mode = 1;
 390                         break;
 391                 }
 392         }
 393
 394         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 395                 duration, nr_readers, nr_writers);
 396         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 397         printf_verbose("Reader duration : %lu loops.\n", rduration);
 398         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 399                         "main", (unsigned long) pthread_self(),
 400                         (unsigned long) gettid());
 401
 402         test_array = calloc(1, sizeof(*test_array) * ARRAY_SIZE);
 403         tid_reader = calloc(nr_readers, sizeof(*tid_reader));
 404         tid_writer = calloc(nr_writers, sizeof(*tid_writer));
 405         count_reader = calloc(nr_readers, sizeof(*count_reader));
 406         count_writer = calloc(nr_writers, sizeof(*count_writer));
 407
 408         next_aff = 0;
 409
 410         for (i = 0; i < nr_readers; i++) {
 411                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 412                                      &count_reader[i]);
 413                 if (err != 0)
 414                         exit(1);
 415         }
 416         for (i = 0; i < nr_writers; i++) {
 417                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 418                                      &count_writer[i]);
 419                 if (err != 0)
 420                         exit(1);
 421         }
 422
 423         cmm_smp_mb();
 424
 425         test_go = 1;
 426
 427         sleep(duration);
 428
 429         test_stop = 1;
 430
 431         for (i = 0; i < nr_readers; i++) {
 432                 err = pthread_join(tid_reader[i], &tret);
 433                 if (err != 0)
 434                         exit(1);
 435                 tot_reads += count_reader[i];
 436         }
 437         for (i = 0; i < nr_writers; i++) {
 438                 err = pthread_join(tid_writer[i], &tret);
 439                 if (err != 0)
 440                         exit(1);
 441                 tot_writes += count_writer[i];
 442         }
 443
 444         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 445                tot_writes);
 446         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu wdur %6lu "
 447                 "nr_writers %3u "
 448                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 449                 argv[0], duration, nr_readers, rduration, wduration,
 450                 nr_writers, wdelay, tot_reads, tot_writes,
 451                 tot_reads + tot_writes);
 452         test_array_free(test_rcu_pointer);
 453         free(test_array);
 454         free(tid_reader);
 455         free(tid_writer);
 456         free(count_reader);
 457         free(count_writer);
 458         return 0;
 459 }