test_qsbr.c

   1 /*
   2  * test_urcu.c
   3  *
   4  * Userspace RCU library - test program
   5  *
   6  * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   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 <stdio.h>
  25 #include <pthread.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30 #include <unistd.h>
  31 #include <stdio.h>
  32 #include <assert.h>
  33 #include <sys/syscall.h>
  34 #include <sched.h>
  35
  36 #include "arch.h"
  37
  38 #if defined(_syscall0)
  39 _syscall0(pid_t, gettid)
  40 #elif defined(__NR_gettid)
  41 static inline pid_t gettid(void)
  42 {
  43         return syscall(__NR_gettid);
  44 }
  45 #else
  46 #warning "use pid as tid"
  47 static inline pid_t gettid(void)
  48 {
  49         return getpid();
  50 }
  51 #endif
  52
  53 #define _LGPL_SOURCE
  54 #include "urcu-qsbr.h"
  55
  56 struct test_array {
  57         int a;
  58 };
  59
  60 static volatile int test_go, test_stop;
  61
  62 static int wdelay;
  63
  64 static struct test_array *test_rcu_pointer;
  65
  66 static unsigned long duration;
  67
  68 /* read-side C.S. duration, in us */
  69 static unsigned long rduration;
  70
  71 /*
  72  * returns 0 if test should end.
  73  */
  74 static int test_duration_write(void)
  75 {
  76         return !test_stop;
  77 }
  78
  79 static int test_duration_read(void)
  80 {
  81         return !test_stop;
  82 }
  83
  84 static unsigned long long __thread nr_writes;
  85 static unsigned long long __thread nr_reads;
  86
  87 static unsigned int nr_readers;
  88 static unsigned int nr_writers;
  89
  90 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
  91
  92 void rcu_copy_mutex_lock(void)
  93 {
  94         int ret;
  95         ret = pthread_mutex_lock(&rcu_copy_mutex);
  96         if (ret) {
  97                 perror("Error in pthread mutex lock");
  98                 exit(-1);
  99         }
 100 }
 101
 102 void rcu_copy_mutex_unlock(void)
 103 {
 104         int ret;
 105
 106         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 107         if (ret) {
 108                 perror("Error in pthread mutex unlock");
 109                 exit(-1);
 110         }
 111 }
 112
 113 /*
 114  * malloc/free are reusing memory areas too quickly, which does not let us
 115  * test races appropriately. Use a large circular array for allocations.
 116  * ARRAY_SIZE is larger than nr_writers, which insures we never run over our tail.
 117  */
 118 #define ARRAY_SIZE (1048576 * nr_writers)
 119 #define ARRAY_POISON 0xDEADBEEF
 120 static int array_index;
 121 static struct test_array *test_array;
 122
 123 static struct test_array *test_array_alloc(void)
 124 {
 125         struct test_array *ret;
 126         int index;
 127
 128         rcu_copy_mutex_lock();
 129         index = array_index % ARRAY_SIZE;
 130         assert(test_array[index].a == ARRAY_POISON ||
 131                 test_array[index].a == 0);
 132         ret = &test_array[index];
 133         array_index++;
 134         if (array_index == ARRAY_SIZE)
 135                 array_index = 0;
 136         rcu_copy_mutex_unlock();
 137         return ret;
 138 }
 139
 140 static void test_array_free(struct test_array *ptr)
 141 {
 142         if (!ptr)
 143                 return;
 144         rcu_copy_mutex_lock();
 145         ptr->a = ARRAY_POISON;
 146         rcu_copy_mutex_unlock();
 147 }
 148
 149 void *thr_reader(void *_count)
 150 {
 151         unsigned long long *count = _count;
 152         struct test_array *local_ptr;
 153
 154         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 155                         "reader", pthread_self(), (unsigned long)gettid());
 156
 157         rcu_register_thread();
 158
 159         while (!test_go)
 160         {
 161         }
 162         smp_mb();
 163
 164         for (;;) {
 165                 _rcu_read_lock();
 166                 local_ptr = _rcu_dereference(test_rcu_pointer);
 167                 debug_yield_read();
 168                 if (local_ptr)
 169                         assert(local_ptr->a == 8);
 170                 if (unlikely(rduration))
 171                         usleep(rduration);
 172                 _rcu_read_unlock();
 173                 nr_reads++;
 174                 /* QS each 1024 reads */
 175                 if (unlikely((nr_reads & ((1 << 10) - 1)) == 0))
 176                         _rcu_quiescent_state();
 177                 if (unlikely(!test_duration_read()))
 178                         break;
 179         }
 180
 181         rcu_unregister_thread();
 182
 183         *count = nr_reads;
 184         printf("thread_end %s, thread id : %lx, tid %lu\n",
 185                         "reader", pthread_self(), (unsigned long)gettid());
 186         return ((void*)1);
 187
 188 }
 189
 190 void *thr_writer(void *_count)
 191 {
 192         unsigned long long *count = _count;
 193         struct test_array *new, *old;
 194
 195         printf("thread_begin %s, thread id : %lx, tid %lu\n",
 196                         "writer", pthread_self(), (unsigned long)gettid());
 197
 198         while (!test_go)
 199         {
 200         }
 201         smp_mb();
 202
 203         for (;;) {
 204                 new = test_array_alloc();
 205                 rcu_copy_mutex_lock();
 206                 old = test_rcu_pointer;
 207                 if (old)
 208                         assert(old->a == 8);
 209                 new->a = 8;
 210                 old = _rcu_publish_content(&test_rcu_pointer, new);
 211                 rcu_copy_mutex_unlock();
 212                 /* can be done after unlock */
 213                 if (old)
 214                         old->a = 0;
 215                 test_array_free(old);
 216                 nr_writes++;
 217                 if (unlikely(!test_duration_write()))
 218                         break;
 219                 if (unlikely(wdelay))
 220                         usleep(wdelay);
 221         }
 222
 223         printf("thread_end %s, thread id : %lx, tid %lu\n",
 224                         "writer", pthread_self(), (unsigned long)gettid());
 225         *count = nr_writes;
 226         return ((void*)2);
 227 }
 228
 229 void show_usage(int argc, char **argv)
 230 {
 231         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 232 #ifdef DEBUG_YIELD
 233         printf(" [-r] [-w] (yield reader and/or writer)");
 234 #endif
 235         printf(" [-d delay] (writer period (us))");
 236         printf(" [-c duration] (reader C.S. duration (us))");
 237         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 238         printf("\n");
 239 }
 240
 241 cpu_set_t affinity;
 242
 243 int main(int argc, char **argv)
 244 {
 245         int err;
 246         pthread_t *tid_reader, *tid_writer;
 247         void *tret;
 248         unsigned long long *count_reader, *count_writer;
 249         unsigned long long tot_reads = 0, tot_writes = 0;
 250         int i, a;
 251         int use_affinity = 0;
 252
 253         if (argc < 4) {
 254                 show_usage(argc, argv);
 255                 return -1;
 256         }
 257
 258         err = sscanf(argv[1], "%u", &nr_readers);
 259         if (err != 1) {
 260                 show_usage(argc, argv);
 261                 return -1;
 262         }
 263
 264         err = sscanf(argv[2], "%u", &nr_writers);
 265         if (err != 1) {
 266                 show_usage(argc, argv);
 267                 return -1;
 268         }
 269
 270         err = sscanf(argv[3], "%lu", &duration);
 271         if (err != 1) {
 272                 show_usage(argc, argv);
 273                 return -1;
 274         }
 275
 276         CPU_ZERO(&affinity);
 277
 278         for (i = 4; i < argc; i++) {
 279                 if (argv[i][0] != '-')
 280                         continue;
 281                 switch (argv[i][1]) {
 282 #ifdef DEBUG_YIELD
 283                 case 'r':
 284                         yield_active |= YIELD_READ;
 285                         break;
 286                 case 'w':
 287                         yield_active |= YIELD_WRITE;
 288                         break;
 289 #endif
 290                 case 'a':
 291                         if (argc < i + 2) {
 292                                 show_usage(argc, argv);
 293                                 return -1;
 294                         }
 295                         a = atoi(argv[++i]);
 296                         CPU_SET(a, &affinity);
 297                         use_affinity = 1;
 298                         printf("Adding CPU %d affinity\n", a);
 299                         break;
 300                 case 'c':
 301                         if (argc < i + 2) {
 302                                 show_usage(argc, argv);
 303                                 return -1;
 304                         }
 305                         rduration = atoi(argv[++i]);
 306                         break;
 307                 case 'd':
 308                         if (argc < i + 2) {
 309                                 show_usage(argc, argv);
 310                                 return -1;
 311                         }
 312                         wdelay = atoi(argv[++i]);
 313                         break;
 314                 }
 315         }
 316
 317         printf("running test for %lu seconds, %u readers, %u writers.\n",
 318                 duration, nr_readers, nr_writers);
 319         printf("Writer delay : %u us.\n", wdelay);
 320         printf("thread %-6s, thread id : %lx, tid %lu\n",
 321                         "main", pthread_self(), (unsigned long)gettid());
 322
 323         if (use_affinity
 324             && sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
 325                 perror("sched_setaffinity");
 326                 exit(-1);
 327         }
 328
 329         test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
 330         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 331         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 332         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 333         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 334
 335         for (i = 0; i < nr_readers; i++) {
 336                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 337                                      &count_reader[i]);
 338                 if (err != 0)
 339                         exit(1);
 340         }
 341         for (i = 0; i < nr_writers; i++) {
 342                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 343                                      &count_writer[i]);
 344                 if (err != 0)
 345                         exit(1);
 346         }
 347
 348         smp_mb();
 349
 350         test_go = 1;
 351
 352         sleep(duration);
 353
 354         test_stop = 1;
 355
 356         for (i = 0; i < nr_readers; i++) {
 357                 err = pthread_join(tid_reader[i], &tret);
 358                 if (err != 0)
 359                         exit(1);
 360                 tot_reads += count_reader[i];
 361         }
 362         for (i = 0; i < nr_writers; i++) {
 363                 err = pthread_join(tid_writer[i], &tret);
 364                 if (err != 0)
 365                         exit(1);
 366                 tot_writes += count_writer[i];
 367         }
 368
 369         printf("total number of reads : %llu, writes %llu\n", tot_reads,
 370                tot_writes);
 371         test_array_free(test_rcu_pointer);
 372         free(test_array);
 373         free(tid_reader);
 374         free(tid_writer);
 375         free(count_reader);
 376         free(count_writer);
 377         return 0;
 378 }