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 #else
  97 #error Invalid TEST_LIST_TYPE
  98 #endif
  99     struct rcu_head rcu;
 100 };
 101
 102 static void reclaim_list_el(struct rcu_head *prcu)
 103 {
 104     struct list_element *el = container_of(prcu, struct list_element, rcu);
 105     g_free(el);
 106     /* Accessed only from call_rcu thread.  */
 107     atomic_set_i64(&n_reclaims, n_reclaims + 1);
 108 }
 109
 110 #if TEST_LIST_TYPE == 1
 111 static QLIST_HEAD(, list_element) Q_list_head;
 112
 113 #define TEST_NAME "qlist"
 114 #define TEST_LIST_REMOVE_RCU        QLIST_REMOVE_RCU
 115 #define TEST_LIST_INSERT_AFTER_RCU  QLIST_INSERT_AFTER_RCU
 116 #define TEST_LIST_INSERT_HEAD_RCU   QLIST_INSERT_HEAD_RCU
 117 #define TEST_LIST_FOREACH_RCU       QLIST_FOREACH_RCU
 118 #define TEST_LIST_FOREACH_SAFE_RCU  QLIST_FOREACH_SAFE_RCU
 119
 120 #elif TEST_LIST_TYPE == 2
 121 static QSIMPLEQ_HEAD(, list_element) Q_list_head =
 122     QSIMPLEQ_HEAD_INITIALIZER(Q_list_head);
 123
 124 #define TEST_NAME "qsimpleq"
 125 #define TEST_LIST_REMOVE_RCU(el, f)                             \
 126          QSIMPLEQ_REMOVE_RCU(&Q_list_head, el, list_element, f)
 127
 128 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f)               \
 129          QSIMPLEQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
 130
 131 #define TEST_LIST_INSERT_HEAD_RCU   QSIMPLEQ_INSERT_HEAD_RCU
 132 #define TEST_LIST_FOREACH_RCU       QSIMPLEQ_FOREACH_RCU
 133 #define TEST_LIST_FOREACH_SAFE_RCU  QSIMPLEQ_FOREACH_SAFE_RCU
 134
 135 #elif TEST_LIST_TYPE == 3
 136 static QTAILQ_HEAD(, list_element) Q_list_head;
 137
 138 #define TEST_NAME "qtailq"
 139 #define TEST_LIST_REMOVE_RCU(el, f) QTAILQ_REMOVE_RCU(&Q_list_head, el, f)
 140
 141 #define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f)               \
 142            QTAILQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
 143
 144 #define TEST_LIST_INSERT_HEAD_RCU   QTAILQ_INSERT_HEAD_RCU
 145 #define TEST_LIST_FOREACH_RCU       QTAILQ_FOREACH_RCU
 146 #define TEST_LIST_FOREACH_SAFE_RCU  QTAILQ_FOREACH_SAFE_RCU
 147 #else
 148 #error Invalid TEST_LIST_TYPE
 149 #endif
 150
 151 static void *rcu_q_reader(void *arg)
 152 {
 153     long long n_reads_local = 0;
 154     struct list_element *el;
 155
 156     rcu_register_thread();
 157
 158     *(struct rcu_reader_data **)arg = &rcu_reader;
 159     atomic_inc(&nthreadsrunning);
 160     while (atomic_read(&goflag) == GOFLAG_INIT) {
 161         g_usleep(1000);
 162     }
 163
 164     while (atomic_read(&goflag) == GOFLAG_RUN) {
 165         rcu_read_lock();
 166         TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
 167             n_reads_local++;
 168             if (atomic_read(&goflag) == GOFLAG_STOP) {
 169                 break;
 170             }
 171         }
 172         rcu_read_unlock();
 173
 174         g_usleep(100);
 175     }
 176     qemu_mutex_lock(&counts_mutex);
 177     n_reads += n_reads_local;
 178     qemu_mutex_unlock(&counts_mutex);
 179
 180     rcu_unregister_thread();
 181     return NULL;
 182 }
 183
 184
 185 static void *rcu_q_updater(void *arg)
 186 {
 187     int j, target_el;
 188     long long n_nodes_local = 0;
 189     long long n_updates_local = 0;
 190     long long n_removed_local = 0;
 191     struct list_element *el, *prev_el;
 192
 193     *(struct rcu_reader_data **)arg = &rcu_reader;
 194     atomic_inc(&nthreadsrunning);
 195     while (atomic_read(&goflag) == GOFLAG_INIT) {
 196         g_usleep(1000);
 197     }
 198
 199     while (atomic_read(&goflag) == GOFLAG_RUN) {
 200         target_el = select_random_el(RCU_Q_LEN);
 201         j = 0;
 202         /* FOREACH_RCU could work here but let's use both macros */
 203         TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 204             j++;
 205             if (target_el == j) {
 206                 TEST_LIST_REMOVE_RCU(prev_el, entry);
 207                 /* may be more than one updater in the future */
 208                 call_rcu1(&prev_el->rcu, reclaim_list_el);
 209                 n_removed_local++;
 210                 break;
 211             }
 212         }
 213         if (atomic_read(&goflag) == GOFLAG_STOP) {
 214             break;
 215         }
 216         target_el = select_random_el(RCU_Q_LEN);
 217         j = 0;
 218         TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
 219             j++;
 220             if (target_el == j) {
 221                 struct list_element *new_el = g_new(struct list_element, 1);
 222                 n_nodes += n_nodes_local;
 223                 TEST_LIST_INSERT_AFTER_RCU(el, new_el, entry);
 224                 break;
 225             }
 226         }
 227
 228         n_updates_local += 2;
 229         synchronize_rcu();
 230     }
 231     synchronize_rcu();
 232     qemu_mutex_lock(&counts_mutex);
 233     n_nodes += n_nodes_local;
 234     n_updates += n_updates_local;
 235     atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local);
 236     qemu_mutex_unlock(&counts_mutex);
 237     return NULL;
 238 }
 239
 240 static void rcu_qtest_init(void)
 241 {
 242     struct list_element *new_el;
 243     int i;
 244     nthreadsrunning = 0;
 245     srand(time(0));
 246     for (i = 0; i < RCU_Q_LEN; i++) {
 247         new_el = g_new(struct list_element, 1);
 248         TEST_LIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry);
 249     }
 250     qemu_mutex_lock(&counts_mutex);
 251     n_nodes += RCU_Q_LEN;
 252     qemu_mutex_unlock(&counts_mutex);
 253 }
 254
 255 static void rcu_qtest_run(int duration, int nreaders)
 256 {
 257     int nthreads = nreaders + 1;
 258     while (atomic_read(&nthreadsrunning) < nthreads) {
 259         g_usleep(1000);
 260     }
 261
 262     atomic_set(&goflag, GOFLAG_RUN);
 263     sleep(duration);
 264     atomic_set(&goflag, GOFLAG_STOP);
 265     wait_all_threads();
 266 }
 267
 268
 269 static void rcu_qtest(const char *test, int duration, int nreaders)
 270 {
 271     int i;
 272     long long n_removed_local = 0;
 273
 274     struct list_element *el, *prev_el;
 275
 276     rcu_qtest_init();
 277     for (i = 0; i < nreaders; i++) {
 278         create_thread(rcu_q_reader);
 279     }
 280     create_thread(rcu_q_updater);
 281     rcu_qtest_run(duration, nreaders);
 282
 283     TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 284         TEST_LIST_REMOVE_RCU(prev_el, entry);
 285         call_rcu1(&prev_el->rcu, reclaim_list_el);
 286         n_removed_local++;
 287     }
 288     qemu_mutex_lock(&counts_mutex);
 289     atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local);
 290     qemu_mutex_unlock(&counts_mutex);
 291     synchronize_rcu();
 292     while (atomic_read_i64(&n_nodes_removed) > atomic_read_i64(&n_reclaims)) {
 293         g_usleep(100);
 294         synchronize_rcu();
 295     }
 296     if (g_test_in_charge) {
 297         g_assert_cmpint(atomic_read_i64(&n_nodes_removed), ==,
 298                         atomic_read_i64(&n_reclaims));
 299     } else {
 300         printf("%s: %d readers; 1 updater; nodes read: "  \
 301                "%lld, nodes removed: %"PRIi64"; nodes reclaimed: %"PRIi64"\n",
 302                test, nthreadsrunning - 1, n_reads,
 303                atomic_read_i64(&n_nodes_removed), atomic_read_i64(&n_reclaims));
 304         exit(0);
 305     }
 306 }
 307
 308 static void usage(int argc, char *argv[])
 309 {
 310     fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]);
 311     exit(-1);
 312 }
 313
 314 static int gtest_seconds;
 315
 316 static void gtest_rcuq_one(void)
 317 {
 318     rcu_qtest("rcuqtest", gtest_seconds / 4, 1);
 319 }
 320
 321 static void gtest_rcuq_few(void)
 322 {
 323     rcu_qtest("rcuqtest", gtest_seconds / 4, 5);
 324 }
 325
 326 static void gtest_rcuq_many(void)
 327 {
 328     rcu_qtest("rcuqtest", gtest_seconds / 2, 20);
 329 }
 330
 331
 332 int main(int argc, char *argv[])
 333 {
 334     int duration = 0, readers = 0;
 335
 336     qemu_mutex_init(&counts_mutex);
 337     if (argc >= 2) {
 338         if (argv[1][0] == '-') {
 339             g_test_init(&argc, &argv, NULL);
 340             if (g_test_quick()) {
 341                 gtest_seconds = 4;
 342             } else {
 343                 gtest_seconds = 20;
 344             }
 345             g_test_add_func("/rcu/"TEST_NAME"/single-threaded", gtest_rcuq_one);
 346             g_test_add_func("/rcu/"TEST_NAME"/short-few", gtest_rcuq_few);
 347             g_test_add_func("/rcu/"TEST_NAME"/long-many", gtest_rcuq_many);
 348             g_test_in_charge = 1;
 349             return g_test_run();
 350         }
 351         duration = strtoul(argv[1], NULL, 0);
 352     }
 353     if (argc >= 3) {
 354         readers = strtoul(argv[2], NULL, 0);
 355     }
 356     if (duration && readers) {
 357         rcu_qtest(argv[0], duration, readers);
 358         return 0;
 359     }
 360
 361     usage(argc, argv);
 362     return -1;
 363 }