tests/test_urcu_qsbr.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-qsbr.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         CPU_ZERO(&mask);
 134         CPU_SET(cpu, &mask);
 135 #if SCHED_SETAFFINITY_ARGS == 2
 136         sched_setaffinity(0, &mask);
 137 #else
 138         sched_setaffinity(0, sizeof(mask), &mask);
 139 #endif
 140 #endif /* HAVE_SCHED_SETAFFINITY */
 141 }
 142
 143 /*
 144  * returns 0 if test should end.
 145  */
 146 static int test_duration_write(void)
 147 {
 148         return !test_stop;
 149 }
 150
 151 static int test_duration_read(void)
 152 {
 153         return !test_stop;
 154 }
 155
 156 static unsigned long long __thread nr_writes;
 157 static unsigned long long __thread nr_reads;
 158
 159 static unsigned int nr_readers;
 160 static unsigned int nr_writers;
 161
 162 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 163
 164 void rcu_copy_mutex_lock(void)
 165 {
 166         int ret;
 167         ret = pthread_mutex_lock(&rcu_copy_mutex);
 168         if (ret) {
 169                 perror("Error in pthread mutex lock");
 170                 exit(-1);
 171         }
 172 }
 173
 174 void rcu_copy_mutex_unlock(void)
 175 {
 176         int ret;
 177
 178         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 179         if (ret) {
 180                 perror("Error in pthread mutex unlock");
 181                 exit(-1);
 182         }
 183 }
 184
 185 /*
 186  * malloc/free are reusing memory areas too quickly, which does not let us
 187  * test races appropriately. Use a large circular array for allocations.
 188  * ARRAY_SIZE is larger than nr_writers, and we keep the mutex across
 189  * both alloc and free, which insures we never run over our tail.
 190  */
 191 #define ARRAY_SIZE (1048576 * nr_writers)
 192 #define ARRAY_POISON 0xDEADBEEF
 193 static int array_index;
 194 static struct test_array *test_array;
 195
 196 static struct test_array *test_array_alloc(void)
 197 {
 198         struct test_array *ret;
 199         int index;
 200
 201         index = array_index % ARRAY_SIZE;
 202         assert(test_array[index].a == ARRAY_POISON ||
 203                 test_array[index].a == 0);
 204         ret = &test_array[index];
 205         array_index++;
 206         if (array_index == ARRAY_SIZE)
 207                 array_index = 0;
 208         return ret;
 209 }
 210
 211 static void test_array_free(struct test_array *ptr)
 212 {
 213         if (!ptr)
 214                 return;
 215         ptr->a = ARRAY_POISON;
 216 }
 217
 218 void *thr_reader(void *_count)
 219 {
 220         unsigned long long *count = _count;
 221         struct test_array *local_ptr;
 222
 223         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 224                         "reader", pthread_self(), (unsigned long)gettid());
 225
 226         set_affinity();
 227
 228         rcu_register_thread();
 229
 230         while (!test_go)
 231         {
 232         }
 233         cmm_smp_mb();
 234
 235         for (;;) {
 236                 rcu_read_lock();
 237                 local_ptr = rcu_dereference(test_rcu_pointer);
 238                 debug_yield_read();
 239                 if (local_ptr)
 240                         assert(local_ptr->a == 8);
 241                 if (caa_unlikely(rduration))
 242                         loop_sleep(rduration);
 243                 rcu_read_unlock();
 244                 nr_reads++;
 245                 /* QS each 1024 reads */
 246                 if (caa_unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 247                         rcu_quiescent_state();
 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 = 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                 /* can be done after unlock */
 289                 if (old)
 290                         old->a = 0;
 291                 test_array_free(old);
 292                 rcu_copy_mutex_unlock();
 293                 nr_writes++;
 294                 if (caa_unlikely(!test_duration_write()))
 295                         break;
 296                 if (caa_unlikely(wdelay))
 297                         loop_sleep(wdelay);
 298         }
 299
 300         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 301                         "writer", pthread_self(), (unsigned long)gettid());
 302         *count = nr_writes;
 303         return ((void*)2);
 304 }
 305
 306 void show_usage(int argc, char **argv)
 307 {
 308         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 309 #ifdef DEBUG_YIELD
 310         printf(" [-r] [-w] (yield reader and/or writer)");
 311 #endif
 312         printf(" [-d delay] (writer period (us))");
 313         printf(" [-c duration] (reader C.S. duration (in loops))");
 314         printf(" [-e duration] (writer C.S. duration (in loops))");
 315         printf(" [-v] (verbose output)");
 316         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 317         printf("\n");
 318 }
 319
 320 int main(int argc, char **argv)
 321 {
 322         int err;
 323         pthread_t *tid_reader, *tid_writer;
 324         void *tret;
 325         unsigned long long *count_reader, *count_writer;
 326         unsigned long long tot_reads = 0, tot_writes = 0;
 327         int i, a;
 328
 329         if (argc < 4) {
 330                 show_usage(argc, argv);
 331                 return -1;
 332         }
 333
 334         err = sscanf(argv[1], "%u", &nr_readers);
 335         if (err != 1) {
 336                 show_usage(argc, argv);
 337                 return -1;
 338         }
 339
 340         err = sscanf(argv[2], "%u", &nr_writers);
 341         if (err != 1) {
 342                 show_usage(argc, argv);
 343                 return -1;
 344         }
 345
 346         err = sscanf(argv[3], "%lu", &duration);
 347         if (err != 1) {
 348                 show_usage(argc, argv);
 349                 return -1;
 350         }
 351
 352         for (i = 4; i < argc; i++) {
 353                 if (argv[i][0] != '-')
 354                         continue;
 355                 switch (argv[i][1]) {
 356 #ifdef DEBUG_YIELD
 357                 case 'r':
 358                         yield_active |= YIELD_READ;
 359                         break;
 360                 case 'w':
 361                         yield_active |= YIELD_WRITE;
 362                         break;
 363 #endif
 364                 case 'a':
 365                         if (argc < i + 2) {
 366                                 show_usage(argc, argv);
 367                                 return -1;
 368                         }
 369                         a = atoi(argv[++i]);
 370                         cpu_affinities[next_aff++] = a;
 371                         use_affinity = 1;
 372                         printf_verbose("Adding CPU %d affinity\n", a);
 373                         break;
 374                 case 'c':
 375                         if (argc < i + 2) {
 376                                 show_usage(argc, argv);
 377                                 return -1;
 378                         }
 379                         rduration = atol(argv[++i]);
 380                         break;
 381                 case 'd':
 382                         if (argc < i + 2) {
 383                                 show_usage(argc, argv);
 384                                 return -1;
 385                         }
 386                         wdelay = atol(argv[++i]);
 387                         break;
 388                 case 'e':
 389                         if (argc < i + 2) {
 390                                 show_usage(argc, argv);
 391                                 return -1;
 392                         }
 393                         wduration = atol(argv[++i]);
 394                         break;
 395                 case 'v':
 396                         verbose_mode = 1;
 397                         break;
 398                 }
 399         }
 400
 401         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 402                 duration, nr_readers, nr_writers);
 403         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 404         printf_verbose("Reader duration : %lu loops.\n", rduration);
 405         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 406                         "main", pthread_self(), (unsigned long)gettid());
 407
 408         test_array = calloc(1, sizeof(*test_array) * ARRAY_SIZE);
 409         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 410         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 411         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 412         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 413
 414         next_aff = 0;
 415
 416         for (i = 0; i < nr_readers; i++) {
 417                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 418                                      &count_reader[i]);
 419                 if (err != 0)
 420                         exit(1);
 421         }
 422         for (i = 0; i < nr_writers; i++) {
 423                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 424                                      &count_writer[i]);
 425                 if (err != 0)
 426                         exit(1);
 427         }
 428
 429         cmm_smp_mb();
 430
 431         test_go = 1;
 432
 433         sleep(duration);
 434
 435         test_stop = 1;
 436
 437         for (i = 0; i < nr_readers; i++) {
 438                 err = pthread_join(tid_reader[i], &tret);
 439                 if (err != 0)
 440                         exit(1);
 441                 tot_reads += count_reader[i];
 442         }
 443         for (i = 0; i < nr_writers; i++) {
 444                 err = pthread_join(tid_writer[i], &tret);
 445                 if (err != 0)
 446                         exit(1);
 447                 tot_writes += count_writer[i];
 448         }
 449
 450         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 451                tot_writes);
 452         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu wdur %6lu "
 453                 "nr_writers %3u "
 454                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 455                 argv[0], duration, nr_readers, rduration, wduration,
 456                 nr_writers, wdelay, tot_reads, tot_writes,
 457                 tot_reads + tot_writes);
 458         test_array_free(test_rcu_pointer);
 459         free(test_array);
 460         free(tid_reader);
 461         free(tid_writer);
 462         free(count_reader);
 463         free(count_writer);
 464         return 0;
 465 }