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 /* hardcoded number of CPUs */
  42 #define NR_CPUS 16384
  43
  44 #if defined(_syscall0)
  45 _syscall0(pid_t, gettid)
  46 #elif defined(__NR_gettid)
  47 static inline pid_t gettid(void)
  48 {
  49         return syscall(__NR_gettid);
  50 }
  51 #else
  52 #warning "use pid as tid"
  53 static inline pid_t gettid(void)
  54 {
  55         return getpid();
  56 }
  57 #endif
  58
  59 #ifndef DYNAMIC_LINK_TEST
  60 #define _LGPL_SOURCE
  61 #else
  62 #define debug_yield_read()
  63 #endif
  64 #include "urcu.h"
  65
  66 struct test_array {
  67         int a;
  68 };
  69
  70 pthread_rwlock_t lock = PTHREAD_RWLOCK_INITIALIZER;
  71
  72 static volatile int test_go, test_stop;
  73
  74 static unsigned long wdelay;
  75
  76 static volatile struct test_array test_array = { 8 };
  77
  78 static unsigned long duration;
  79
  80 /* read-side C.S. duration, in loops */
  81 static unsigned long rduration;
  82
  83 static inline void loop_sleep(unsigned long l)
  84 {
  85         while(l-- != 0)
  86                 cpu_relax();
  87 }
  88
  89 static int verbose_mode;
  90
  91 #define printf_verbose(fmt, args...)            \
  92         do {                                    \
  93                 if (verbose_mode)               \
  94                         printf(fmt, args);      \
  95         } while (0)
  96
  97 static unsigned int cpu_affinities[NR_CPUS];
  98 static unsigned int next_aff = 0;
  99 static int use_affinity = 0;
 100
 101 pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
 102
 103 static void set_affinity(void)
 104 {
 105         cpu_set_t mask;
 106         int cpu;
 107         int ret;
 108
 109         if (!use_affinity)
 110                 return;
 111
 112         ret = pthread_mutex_lock(&affinity_mutex);
 113         if (ret) {
 114                 perror("Error in pthread mutex lock");
 115                 exit(-1);
 116         }
 117         cpu = cpu_affinities[next_aff++];
 118         ret = pthread_mutex_unlock(&affinity_mutex);
 119         if (ret) {
 120                 perror("Error in pthread mutex unlock");
 121                 exit(-1);
 122         }
 123         CPU_ZERO(&mask);
 124         CPU_SET(cpu, &mask);
 125         sched_setaffinity(0, sizeof(mask), &mask);
 126 }
 127
 128 /*
 129  * returns 0 if test should end.
 130  */
 131 static int test_duration_write(void)
 132 {
 133         return !test_stop;
 134 }
 135
 136 static int test_duration_read(void)
 137 {
 138         return !test_stop;
 139 }
 140
 141 static unsigned long long __thread nr_writes;
 142 static unsigned long long __thread nr_reads;
 143
 144 static unsigned int nr_readers;
 145 static unsigned int nr_writers;
 146
 147 pthread_mutex_t rcu_copy_mutex = PTHREAD_MUTEX_INITIALIZER;
 148
 149 void rcu_copy_mutex_lock(void)
 150 {
 151         int ret;
 152         ret = pthread_mutex_lock(&rcu_copy_mutex);
 153         if (ret) {
 154                 perror("Error in pthread mutex lock");
 155                 exit(-1);
 156         }
 157 }
 158
 159 void rcu_copy_mutex_unlock(void)
 160 {
 161         int ret;
 162
 163         ret = pthread_mutex_unlock(&rcu_copy_mutex);
 164         if (ret) {
 165                 perror("Error in pthread mutex unlock");
 166                 exit(-1);
 167         }
 168 }
 169
 170 void *thr_reader(void *_count)
 171 {
 172         unsigned long long *count = _count;
 173
 174         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 175                         "reader", pthread_self(), (unsigned long)gettid());
 176
 177         set_affinity();
 178
 179         while (!test_go)
 180         {
 181         }
 182
 183         for (;;) {
 184                 pthread_rwlock_rdlock(&lock);
 185                 assert(test_array.a == 8);
 186                 if (unlikely(rduration))
 187                         loop_sleep(rduration);
 188                 pthread_rwlock_unlock(&lock);
 189                 nr_reads++;
 190                 if (unlikely(!test_duration_read()))
 191                         break;
 192         }
 193
 194         *count = nr_reads;
 195         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 196                         "reader", pthread_self(), (unsigned long)gettid());
 197         return ((void*)1);
 198
 199 }
 200
 201 void *thr_writer(void *_count)
 202 {
 203         unsigned long long *count = _count;
 204
 205         printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
 206                         "writer", pthread_self(), (unsigned long)gettid());
 207
 208         set_affinity();
 209
 210         while (!test_go)
 211         {
 212         }
 213         smp_mb();
 214
 215         for (;;) {
 216                 pthread_rwlock_wrlock(&lock);
 217                 test_array.a = 0;
 218                 test_array.a = 8;
 219                 pthread_rwlock_unlock(&lock);
 220                 nr_writes++;
 221                 if (unlikely(!test_duration_write()))
 222                         break;
 223                 if (unlikely(wdelay))
 224                         loop_sleep(wdelay);
 225         }
 226
 227         printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
 228                         "writer", pthread_self(), (unsigned long)gettid());
 229         *count = nr_writes;
 230         return ((void*)2);
 231 }
 232
 233 void show_usage(int argc, char **argv)
 234 {
 235         printf("Usage : %s nr_readers nr_writers duration (s)", argv[0]);
 236 #ifdef DEBUG_YIELD
 237         printf(" [-r] [-w] (yield reader and/or writer)");
 238 #endif
 239         printf(" [-d delay] (writer period (us))");
 240         printf(" [-c duration] (reader C.S. duration (in loops))");
 241         printf(" [-v] (verbose output)");
 242         printf(" [-a cpu#] [-a cpu#]... (affinity)");
 243         printf("\n");
 244 }
 245
 246 int main(int argc, char **argv)
 247 {
 248         int err;
 249         pthread_t *tid_reader, *tid_writer;
 250         void *tret;
 251         unsigned long long *count_reader, *count_writer;
 252         unsigned long long tot_reads = 0, tot_writes = 0;
 253         int i, a;
 254
 255         if (argc < 4) {
 256                 show_usage(argc, argv);
 257                 return -1;
 258         }
 259         smp_mb();
 260
 261         err = sscanf(argv[1], "%u", &nr_readers);
 262         if (err != 1) {
 263                 show_usage(argc, argv);
 264                 return -1;
 265         }
 266
 267         err = sscanf(argv[2], "%u", &nr_writers);
 268         if (err != 1) {
 269                 show_usage(argc, argv);
 270                 return -1;
 271         }
 272
 273         err = sscanf(argv[3], "%lu", &duration);
 274         if (err != 1) {
 275                 show_usage(argc, argv);
 276                 return -1;
 277         }
 278
 279         for (i = 4; i < argc; i++) {
 280                 if (argv[i][0] != '-')
 281                         continue;
 282                 switch (argv[i][1]) {
 283 #ifdef DEBUG_YIELD
 284                 case 'r':
 285                         yield_active |= YIELD_READ;
 286                         break;
 287                 case 'w':
 288                         yield_active |= YIELD_WRITE;
 289                         break;
 290 #endif
 291                 case 'a':
 292                         if (argc < i + 2) {
 293                                 show_usage(argc, argv);
 294                                 return -1;
 295                         }
 296                         a = atoi(argv[++i]);
 297                         cpu_affinities[next_aff++] = a;
 298                         use_affinity = 1;
 299                         printf_verbose("Adding CPU %d affinity\n", a);
 300                         break;
 301                 case 'c':
 302                         if (argc < i + 2) {
 303                                 show_usage(argc, argv);
 304                                 return -1;
 305                         }
 306                         rduration = atol(argv[++i]);
 307                         break;
 308                 case 'd':
 309                         if (argc < i + 2) {
 310                                 show_usage(argc, argv);
 311                                 return -1;
 312                         }
 313                         wdelay = atol(argv[++i]);
 314                         break;
 315                 case 'v':
 316                         verbose_mode = 1;
 317                         break;
 318                 }
 319         }
 320
 321         printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
 322                 duration, nr_readers, nr_writers);
 323         printf_verbose("Writer delay : %lu loops.\n", wdelay);
 324         printf_verbose("Reader duration : %lu loops.\n", rduration);
 325         printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
 326                         "main", pthread_self(), (unsigned long)gettid());
 327
 328         tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
 329         tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
 330         count_reader = malloc(sizeof(*count_reader) * nr_readers);
 331         count_writer = malloc(sizeof(*count_writer) * nr_writers);
 332
 333         next_aff = 0;
 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_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
 370                tot_writes);
 371         printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
 372                 "nr_writers %3u "
 373                 "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
 374                 argv[0], duration, nr_readers, rduration,
 375                 nr_writers, wdelay, tot_reads, tot_writes,
 376                 tot_reads + tot_writes);
 377
 378         free(tid_reader);
 379         free(tid_writer);
 380         free(count_reader);
 381         free(count_writer);
 382         return 0;
 383 }