tests/test-rcu-list.c

   1 /*
   2  * rcuq_test.c
   3  *
   4  * usage: rcuq_test <readers> <duration>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  *
  20  * Copyright (c) 2013 Mike D. Day, IBM Corporation.
  21  */
  22
  23 #include "qemu/osdep.h"
  24 #include "qemu/atomic.h"
  25 #include "qemu/rcu.h"
  26 #include "qemu/thread.h"
  27 #include "qemu/rcu_queue.h"
  28
  29 /*
  30  * Test variables.
  31  */
  32
  33 static QemuMutex counts_mutex;
  34 static long long n_reads = 0LL;
  35 static long long n_updates = 0LL;
  36 static int64_t n_reclaims;
  37 static int64_t n_nodes_removed;
  38 static long long n_nodes = 0LL;
  39 static int g_test_in_charge = 0;
  40
  41 static int nthreadsrunning;
  42
  43 #define GOFLAG_INIT 0
  44 #define GOFLAG_RUN  1
  45 #define GOFLAG_STOP 2
  46
  47 static int goflag = GOFLAG_INIT;
  48
  49 #define RCU_READ_RUN 1000
  50 #define RCU_UPDATE_RUN 10
  51 #define NR_THREADS 100
  52 #define RCU_Q_LEN 100
  53
  54 static QemuThread threads[NR_THREADS];
  55 static struct rcu_reader_data *data[NR_THREADS];
  56 static int n_threads;
  57
  58 static int select_random_el(int max)
  59 {
  60     return (rand() % max);
  61 }
  62
  63
  64 static void create_thread(void *(*func)(void *))
  65 {
  66     if (n_threads >= NR_THREADS) {
  67         fprintf(stderr, "Thread limit of %d exceeded!\n", NR_THREADS);
  68         exit(-1);
  69     }
  70     qemu_thread_create(&threads[n_threads], "test", func, &data[n_threads],
  71                        QEMU_THREAD_JOINABLE);
  72     n_threads++;
  73 }
  74
  75 static void wait_all_threads(void)
  76 {
  77     int i;
  78
  79     for (i = 0; i < n_threads; i++) {
  80         qemu_thread_join(&threads[i]);
  81     }
  82     n_threads = 0;
  83 }
  84
  85 #ifndef TEST_LIST_TYPE
  86 #define TEST_LIST_TYPE 1
  87 #endif
  88
  89 struct list_element {
  90 #if TEST_LIST_TYPE == 1
  91     QLIST_ENTRY(list_element) entry;
  92 #elif TEST_LIST_TYPE == 2
  93     QSIMPLEQ_ENTRY(list_element) entry;
  94 #elif TEST_LIST_TYPE == 3
  95     QTAILQ_ENTRY(list_element) entry;
  96 #elif TEST_LIST_TYPE == 4
  97     QSLIST_ENTRY(list_element) entry;
  98 #else
  99 #error Invalid TEST_LIST_TYPE
 100 #endif
 101     struct rcu_head rcu;
 102 };
 103
 104 static void reclaim_list_el(struct rcu_head *prcu)
 105 {
 106     struct list_element *el = container_of(prcu, struct list_element, rcu);
 107     g_free(el);
 108     /* Accessed only from call_rcu thread.  */
 109     qatomic_set_i64(&n_reclaims, n_reclaims + 1);
 110 }
 111
 112 #if TEST_LIST_TYPE == 1
 113 static QLIST_HEAD(, list_element) Q_list_head;
 114
 115 #define TEST_NAME "qlist"
 116 #define TEST_LIST_REMOVE_RCU        QLIST_REMOVE_RCU
 117 #define TEST_LIST_INSERT_AFTER_RCU  QLIST_INSERT_AFTER_RCU
 118 #define TEST_LIST_INSERT_HEAD_RCU   QLIST_INSERT_HEAD_RCU
 119 #define TEST_LIST_FOREACH_RCU       QLIST_FOREACH_RCU
 120 #define TEST_LIST_FOREACH_SAFE_RCU  QLIST_FOREACH_SAFE_RCU
 121
 122 #elif TEST_LIST_TYPE == 2
 123 static QSIMPLEQ_HEAD(, list_element) Q_list_head =
 124     QSIMPLEQ_HEAD_INITIALIZER(Q_list_head);
 125
 126 #define TEST_NAME "qsimpleq"
 127 #define TEST_LIST_REMOVE_RCU(el, f)                             \
 128          QSIMPLEQ_REMOVE_RCU(&Q_list_head, el, list_element, f)
 129
 130 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f)               \
 131          QSIMPLEQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
 132
 133 #define TEST_LIST_INSERT_HEAD_RCU   QSIMPLEQ_INSERT_HEAD_RCU
 134 #define TEST_LIST_FOREACH_RCU       QSIMPLEQ_FOREACH_RCU
 135 #define TEST_LIST_FOREACH_SAFE_RCU  QSIMPLEQ_FOREACH_SAFE_RCU
 136
 137 #elif TEST_LIST_TYPE == 3
 138 static QTAILQ_HEAD(, list_element) Q_list_head;
 139
 140 #define TEST_NAME "qtailq"
 141 #define TEST_LIST_REMOVE_RCU(el, f) QTAILQ_REMOVE_RCU(&Q_list_head, el, f)
 142
 143 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f)               \
 144            QTAILQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
 145
 146 #define TEST_LIST_INSERT_HEAD_RCU   QTAILQ_INSERT_HEAD_RCU
 147 #define TEST_LIST_FOREACH_RCU       QTAILQ_FOREACH_RCU
 148 #define TEST_LIST_FOREACH_SAFE_RCU  QTAILQ_FOREACH_SAFE_RCU
 149
 150 #elif TEST_LIST_TYPE == 4
 151 static QSLIST_HEAD(, list_element) Q_list_head;
 152
 153 #define TEST_NAME "qslist"
 154 #define TEST_LIST_REMOVE_RCU(el, f)                              \
 155          QSLIST_REMOVE_RCU(&Q_list_head, el, list_element, f)
 156
 157 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f)               \
 158          QSLIST_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
 159
 160 #define TEST_LIST_INSERT_HEAD_RCU   QSLIST_INSERT_HEAD_RCU
 161 #define TEST_LIST_FOREACH_RCU       QSLIST_FOREACH_RCU
 162 #define TEST_LIST_FOREACH_SAFE_RCU  QSLIST_FOREACH_SAFE_RCU
 163 #else
 164 #error Invalid TEST_LIST_TYPE
 165 #endif
 166
 167 static void *rcu_q_reader(void *arg)
 168 {
 169     long long n_reads_local = 0;
 170     struct list_element *el;
 171
 172     rcu_register_thread();
 173
 174     *(struct rcu_reader_data **)arg = &rcu_reader;
 175     qatomic_inc(&nthreadsrunning);
 176     while (qatomic_read(&goflag) == GOFLAG_INIT) {
 177         g_usleep(1000);
 178     }
 179
 180     while (qatomic_read(&goflag) == GOFLAG_RUN) {
 181         rcu_read_lock();
 182         TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
 183             n_reads_local++;
 184             if (qatomic_read(&goflag) == GOFLAG_STOP) {
 185                 break;
 186             }
 187         }
 188         rcu_read_unlock();
 189
 190         g_usleep(100);
 191     }
 192     qemu_mutex_lock(&counts_mutex);
 193     n_reads += n_reads_local;
 194     qemu_mutex_unlock(&counts_mutex);
 195
 196     rcu_unregister_thread();
 197     return NULL;
 198 }
 199
 200
 201 static void *rcu_q_updater(void *arg)
 202 {
 203     int j, target_el;
 204     long long n_nodes_local = 0;
 205     long long n_updates_local = 0;
 206     long long n_removed_local = 0;
 207     struct list_element *el, *prev_el;
 208
 209     *(struct rcu_reader_data **)arg = &rcu_reader;
 210     qatomic_inc(&nthreadsrunning);
 211     while (qatomic_read(&goflag) == GOFLAG_INIT) {
 212         g_usleep(1000);
 213     }
 214
 215     while (qatomic_read(&goflag) == GOFLAG_RUN) {
 216         target_el = select_random_el(RCU_Q_LEN);
 217         j = 0;
 218         /* FOREACH_RCU could work here but let's use both macros */
 219         TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 220             j++;
 221             if (target_el == j) {
 222                 TEST_LIST_REMOVE_RCU(prev_el, entry);
 223                 /* may be more than one updater in the future */
 224                 call_rcu1(&prev_el->rcu, reclaim_list_el);
 225                 n_removed_local++;
 226                 break;
 227             }
 228         }
 229         if (qatomic_read(&goflag) == GOFLAG_STOP) {
 230             break;
 231         }
 232         target_el = select_random_el(RCU_Q_LEN);
 233         j = 0;
 234         TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
 235             j++;
 236             if (target_el == j) {
 237                 struct list_element *new_el = g_new(struct list_element, 1);
 238                 n_nodes_local++;
 239                 TEST_LIST_INSERT_AFTER_RCU(el, new_el, entry);
 240                 break;
 241             }
 242         }
 243
 244         n_updates_local += 2;
 245         synchronize_rcu();
 246     }
 247     synchronize_rcu();
 248     qemu_mutex_lock(&counts_mutex);
 249     n_nodes += n_nodes_local;
 250     n_updates += n_updates_local;
 251     qatomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local);
 252     qemu_mutex_unlock(&counts_mutex);
 253     return NULL;
 254 }
 255
 256 static void rcu_qtest_init(void)
 257 {
 258     struct list_element *new_el;
 259     int i;
 260     nthreadsrunning = 0;
 261     srand(time(0));
 262     for (i = 0; i < RCU_Q_LEN; i++) {
 263         new_el = g_new(struct list_element, 1);
 264         TEST_LIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry);
 265     }
 266     qemu_mutex_lock(&counts_mutex);
 267     n_nodes += RCU_Q_LEN;
 268     qemu_mutex_unlock(&counts_mutex);
 269 }
 270
 271 static void rcu_qtest_run(int duration, int nreaders)
 272 {
 273     int nthreads = nreaders + 1;
 274     while (qatomic_read(&nthreadsrunning) < nthreads) {
 275         g_usleep(1000);
 276     }
 277
 278     qatomic_set(&goflag, GOFLAG_RUN);
 279     sleep(duration);
 280     qatomic_set(&goflag, GOFLAG_STOP);
 281     wait_all_threads();
 282 }
 283
 284
 285 static void rcu_qtest(const char *test, int duration, int nreaders)
 286 {
 287     int i;
 288     long long n_removed_local = 0;
 289
 290     struct list_element *el, *prev_el;
 291
 292     rcu_qtest_init();
 293     for (i = 0; i < nreaders; i++) {
 294         create_thread(rcu_q_reader);
 295     }
 296     create_thread(rcu_q_updater);
 297     rcu_qtest_run(duration, nreaders);
 298
 299     TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 300         TEST_LIST_REMOVE_RCU(prev_el, entry);
 301         call_rcu1(&prev_el->rcu, reclaim_list_el);
 302         n_removed_local++;
 303     }
 304     qemu_mutex_lock(&counts_mutex);
 305     qatomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local);
 306     qemu_mutex_unlock(&counts_mutex);
 307     synchronize_rcu();
 308     while (qatomic_read_i64(&n_nodes_removed) >
 309            qatomic_read_i64(&n_reclaims)) {
 310         g_usleep(100);
 311         synchronize_rcu();
 312     }
 313     if (g_test_in_charge) {
 314         g_assert_cmpint(qatomic_read_i64(&n_nodes_removed), ==,
 315                         qatomic_read_i64(&n_reclaims));
 316     } else {
 317         printf("%s: %d readers; 1 updater; nodes read: "  \
 318                "%lld, nodes removed: %"PRIi64"; nodes reclaimed: %"PRIi64"\n",
 319                test, nthreadsrunning - 1, n_reads,
 320                qatomic_read_i64(&n_nodes_removed),
 321                qatomic_read_i64(&n_reclaims));
 322         exit(0);
 323     }
 324 }
 325
 326 static void usage(int argc, char *argv[])
 327 {
 328     fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]);
 329     exit(-1);
 330 }
 331
 332 static int gtest_seconds;
 333
 334 static void gtest_rcuq_one(void)
 335 {
 336     rcu_qtest("rcuqtest", gtest_seconds / 4, 1);
 337 }
 338
 339 static void gtest_rcuq_few(void)
 340 {
 341     rcu_qtest("rcuqtest", gtest_seconds / 4, 5);
 342 }
 343
 344 static void gtest_rcuq_many(void)
 345 {
 346     rcu_qtest("rcuqtest", gtest_seconds / 2, 20);
 347 }
 348
 349
 350 int main(int argc, char *argv[])
 351 {
 352     int duration = 0, readers = 0;
 353
 354     qemu_mutex_init(&counts_mutex);
 355     if (argc >= 2) {
 356         if (argv[1][0] == '-') {
 357             g_test_init(&argc, &argv, NULL);
 358             if (g_test_quick()) {
 359                 gtest_seconds = 4;
 360             } else {
 361                 gtest_seconds = 20;
 362             }
 363             g_test_add_func("/rcu/"TEST_NAME"/single-threaded", gtest_rcuq_one);
 364             g_test_add_func("/rcu/"TEST_NAME"/short-few", gtest_rcuq_few);
 365             g_test_add_func("/rcu/"TEST_NAME"/long-many", gtest_rcuq_many);
 366             g_test_in_charge = 1;
 367             return g_test_run();
 368         }
 369         duration = strtoul(argv[1], NULL, 0);
 370     }
 371     if (argc >= 3) {
 372         readers = strtoul(argv[2], NULL, 0);
 373     }
 374     if (duration && readers) {
 375         rcu_qtest(argv[0], duration, readers);
 376         return 0;
 377     }
 378
 379     usage(argc, argv);
 380     return -1;
 381 }