test_rwlock.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 /* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
  39 #define CACHE_LINE_SIZE 4096
  40
  41 #if defined(_syscall0)
  42 _syscall0(pid_t, gettid)
  43 #elif defined(__NR_gettid)
  44 static inline pid_t gettid(void)
  45 {
  46         return syscall(__NR_gettid);
  47 }
  48 #else
  49 #warning "use pid as tid"
  50 static inline pid_t gettid(void)
  51 {
  52         return getpid();
  53 }
  54 #endif
  55
  56 #ifndef DYNAMIC_LINK_TEST
  57 #define _LGPL_SOURCE
  58 #else
  59 #define debug_yield_read()
  60 #endif
  61 #include "urcu.h"
  62
  63 struct test_array {
  64         int a;
  65 };
  66
  67 pthread_rwlock_t lock = PTHREAD_RWLOCK_INITIALIZER;
  68
  69 static volatile int test_go, test_stop;
  70
  71 static unsigned long wdelay;
  72
  73 static volatile struct test_array test_array = { 8 };
  74
  75 static unsigned long duration;
  76
  77 /* read-side C.S. duration, in loops */
  78 static unsigned long rduration;
  79
  80 static inline void loop_sleep(unsigned long l)
  81 {
  82         while(l-- != 0)
  83                 cpu_relax();
  84 }
  85
  86 static int verbose_mode;
  87
  88 #define printf_verbose(fmt, args...)            \
  89         do {                                    \
  90                 if (verbose_mode)               \
  91                         printf(fmt, args);      \
  92         } while (0)
  93
  94 /*
  95  * returns 0 if test should end.
  96  */
  97 static int test_duration_write(void)
  98 {
  99         return !test_stop;
 100 }
 101
 102 static int test_duration_read(void)
 103 {
 104         return !test_stop;
 105 }
 106
 107 static unsigned long long __thread nr_writes;
 108 static unsigned long long __thread nr_reads;
 109
 110 static unsigned int nr_readers;
 111 static unsigned int nr_writers;
 112
 113 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 114
 115 void rcu_copy_mutex_lock(void)
 116 {
 117         int ret;
 118         ret = pthread_mutex_lock(&rcu_copy_mutex);
 119         if (ret) {
 120                 perror("Error in pthread mutex lock");
 121                 exit(-1);
 122         }
 123 }
 124
 125 void rcu_copy_mutex_unlock(void)
 126 {
 127         int ret;
 128
 129         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 130         if (ret) {
 131                 perror("Error in pthread mutex unlock");
 132                 exit(-1);
 133         }
 134 }
 135
 136 void *thr_reader(void *_count)
 137 {
 138         unsigned long long *count = _count;
 139
 140         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 141                         "reader", pthread_self(), (unsigned long)gettid());
 142
 143         while (!test_go)
 144         {
 145         }
 146
 147         for (;;) {
 148                 pthread_rwlock_rdlock(&lock);
 149                 assert(test_array.a == 8);
 150                 if (unlikely(rduration))
 151                         loop_sleep(rduration);
 152                 pthread_rwlock_unlock(&lock);
 153                 nr_reads++;
 154                 if (unlikely(!test_duration_read()))
 155                         break;
 156         }
 157
 158         *count = nr_reads;
 159         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 160                         "reader", pthread_self(), (unsigned long)gettid());
 161         return ((void*)1);
 162
 163 }
 164
 165 void *thr_writer(void *_count)
 166 {
 167         unsigned long long *count = _count;
 168
 169         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 170                         "writer", pthread_self(), (unsigned long)gettid());
 171
 172         while (!test_go)
 173         {
 174         }
 175         smp_mb();
 176
 177         for (;;) {
 178                 pthread_rwlock_wrlock(&lock);
 179                 test_array.a = 0;
 180                 test_array.a = 8;
 181                 pthread_rwlock_unlock(&lock);
 182                 nr_writes++;
 183                 if (unlikely(!test_duration_write()))
 184                         break;
 185                 if (unlikely(wdelay))
 186                         loop_sleep(wdelay);
 187         }
 188
 189         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 190                         "writer", pthread_self(), (unsigned long)gettid());
 191         *count = nr_writes;
 192         return ((void*)2);
 193 }
 194
 195 void show_usage(int argc, char **argv)
 196 {
 197         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 198 #ifdef DEBUG_YIELD
 199         printf(" [-r] [-w] (yield reader and/or writer)");
 200 #endif
 201         printf(" [-d delay] (writer period (us))");
 202         printf(" [-c duration] (reader C.S. duration (in loops))");
 203         printf(" [-v] (verbose output)");
 204         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 205         printf("\n");
 206 }
 207
 208 cpu_set_t affinity;
 209
 210 int main(int argc, char **argv)
 211 {
 212         int err;
 213         pthread_t *tid_reader, *tid_writer;
 214         void *tret;
 215         unsigned long long *count_reader, *count_writer;
 216         unsigned long long tot_reads = 0, tot_writes = 0;
 217         int i, a;
 218         int use_affinity = 0;
 219
 220         if (argc < 4) {
 221                 show_usage(argc, argv);
 222                 return -1;
 223         }
 224         smp_mb();
 225
 226         err = sscanf(argv[1], "%u", &nr_readers);
 227         if (err != 1) {
 228                 show_usage(argc, argv);
 229                 return -1;
 230         }
 231
 232         err = sscanf(argv[2], "%u", &nr_writers);
 233         if (err != 1) {
 234                 show_usage(argc, argv);
 235                 return -1;
 236         }
 237
 238         err = sscanf(argv[3], "%lu", &duration);
 239         if (err != 1) {
 240                 show_usage(argc, argv);
 241                 return -1;
 242         }
 243
 244         CPU_ZERO(&affinity);
 245
 246         for (i = 4; i < argc; i++) {
 247                 if (argv[i][0] != '-')
 248                         continue;
 249                 switch (argv[i][1]) {
 250 #ifdef DEBUG_YIELD
 251                 case 'r':
 252                         yield_active |= YIELD_READ;
 253                         break;
 254                 case 'w':
 255                         yield_active |= YIELD_WRITE;
 256                         break;
 257 #endif
 258                 case 'a':
 259                         if (argc < i + 2) {
 260                                 show_usage(argc, argv);
 261                                 return -1;
 262                         }
 263                         a = atoi(argv[++i]);
 264                         CPU_SET(a, &affinity);
 265                         use_affinity = 1;
 266                         printf_verbose("Adding CPU %d affinity\n", a);
 267                         break;
 268                 case 'c':
 269                         if (argc < i + 2) {
 270                                 show_usage(argc, argv);
 271                                 return -1;
 272                         }
 273                         rduration = atol(argv[++i]);
 274                         break;
 275                 case 'd':
 276                         if (argc < i + 2) {
 277                                 show_usage(argc, argv);
 278                                 return -1;
 279                         }
 280                         wdelay = atol(argv[++i]);
 281                         break;
 282                 case 'v':
 283                         verbose_mode = 1;
 284                         break;
 285                 }
 286         }
 287
 288         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 289                 duration, nr_readers, nr_writers);
 290         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 291         printf_verbose("Reader duration : %lu loops.\n", rduration);
 292         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 293                         "main", pthread_self(), (unsigned long)gettid());
 294         if (use_affinity
 295             && sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
 296                 perror("sched_setaffinity");
 297                 exit(-1);
 298         }
 299
 300         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 301         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 302         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 303         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 304
 305         for (i = 0; i < nr_readers; i++) {
 306                 err = pthread_create(&tid_reader[i], NULL, thr_reader,
 307                                      &count_reader[i]);
 308                 if (err != 0)
 309                         exit(1);
 310         }
 311         for (i = 0; i < nr_writers; i++) {
 312                 err = pthread_create(&tid_writer[i], NULL, thr_writer,
 313                                      &count_writer[i]);
 314                 if (err != 0)
 315                         exit(1);
 316         }
 317
 318         smp_mb();
 319
 320         test_go = 1;
 321
 322         sleep(duration);
 323
 324         test_stop = 1;
 325
 326         for (i = 0; i < nr_readers; i++) {
 327                 err = pthread_join(tid_reader[i], &tret);
 328                 if (err != 0)
 329                         exit(1);
 330                 tot_reads += count_reader[i];
 331         }
 332         for (i = 0; i < nr_writers; i++) {
 333                 err = pthread_join(tid_writer[i], &tret);
 334                 if (err != 0)
 335                         exit(1);
 336                 tot_writes += count_writer[i];
 337         }
 338
 339         printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 340                tot_writes);
 341         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 342                 "nr_writers %3u "
 343                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 344                 argv[0], duration, nr_readers, rduration,
 345                 nr_writers, wdelay, tot_reads, tot_writes,
 346                 tot_reads + tot_writes);
 347
 348         free(tid_reader);
 349         free(tid_writer);
 350         free(count_reader);
 351         free(count_writer);
 352         return 0;
 353 }