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