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 long long n_reclaims = 0LL;
  37 static long long n_nodes_removed = 0LL;
  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 #else
  93 #error Invalid TEST_LIST_TYPE
  94 #endif
  95     struct rcu_head rcu;
  96 };
  97
  98 static void reclaim_list_el(struct rcu_head *prcu)
  99 {
 100     struct list_element *el = container_of(prcu, struct list_element, rcu);
 101     g_free(el);
 102     /* Accessed only from call_rcu thread.  */
 103     n_reclaims++;
 104 }
 105
 106 #if TEST_LIST_TYPE == 1
 107 static QLIST_HEAD(q_list_head, list_element) Q_list_head;
 108
 109 #define TEST_NAME "qlist"
 110 #define TEST_LIST_REMOVE_RCU        QLIST_REMOVE_RCU
 111 #define TEST_LIST_INSERT_AFTER_RCU  QLIST_INSERT_AFTER_RCU
 112 #define TEST_LIST_INSERT_HEAD_RCU   QLIST_INSERT_HEAD_RCU
 113 #define TEST_LIST_FOREACH_RCU       QLIST_FOREACH_RCU
 114 #define TEST_LIST_FOREACH_SAFE_RCU  QLIST_FOREACH_SAFE_RCU
 115 #else
 116 #error Invalid TEST_LIST_TYPE
 117 #endif
 118
 119 static void *rcu_q_reader(void *arg)
 120 {
 121     long long n_reads_local = 0;
 122     struct list_element *el;
 123
 124     rcu_register_thread();
 125
 126     *(struct rcu_reader_data **)arg = &rcu_reader;
 127     atomic_inc(&nthreadsrunning);
 128     while (atomic_read(&goflag) == GOFLAG_INIT) {
 129         g_usleep(1000);
 130     }
 131
 132     while (atomic_read(&goflag) == GOFLAG_RUN) {
 133         rcu_read_lock();
 134         TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
 135             n_reads_local++;
 136             if (atomic_read(&goflag) == GOFLAG_STOP) {
 137                 break;
 138             }
 139         }
 140         rcu_read_unlock();
 141
 142         g_usleep(100);
 143     }
 144     qemu_mutex_lock(&counts_mutex);
 145     n_reads += n_reads_local;
 146     qemu_mutex_unlock(&counts_mutex);
 147
 148     rcu_unregister_thread();
 149     return NULL;
 150 }
 151
 152
 153 static void *rcu_q_updater(void *arg)
 154 {
 155     int j, target_el;
 156     long long n_nodes_local = 0;
 157     long long n_updates_local = 0;
 158     long long n_removed_local = 0;
 159     struct list_element *el, *prev_el;
 160
 161     *(struct rcu_reader_data **)arg = &rcu_reader;
 162     atomic_inc(&nthreadsrunning);
 163     while (atomic_read(&goflag) == GOFLAG_INIT) {
 164         g_usleep(1000);
 165     }
 166
 167     while (atomic_read(&goflag) == GOFLAG_RUN) {
 168         target_el = select_random_el(RCU_Q_LEN);
 169         j = 0;
 170         /* FOREACH_RCU could work here but let's use both macros */
 171         TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 172             j++;
 173             if (target_el == j) {
 174                 TEST_LIST_REMOVE_RCU(prev_el, entry);
 175                 /* may be more than one updater in the future */
 176                 call_rcu1(&prev_el->rcu, reclaim_list_el);
 177                 n_removed_local++;
 178                 break;
 179             }
 180         }
 181         if (atomic_read(&goflag) == GOFLAG_STOP) {
 182             break;
 183         }
 184         target_el = select_random_el(RCU_Q_LEN);
 185         j = 0;
 186         TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
 187             j++;
 188             if (target_el == j) {
 189                 struct list_element *new_el = g_new(struct list_element, 1);
 190                 n_nodes += n_nodes_local;
 191                 TEST_LIST_INSERT_AFTER_RCU(el, new_el, entry);
 192                 break;
 193             }
 194         }
 195
 196         n_updates_local += 2;
 197         synchronize_rcu();
 198     }
 199     synchronize_rcu();
 200     qemu_mutex_lock(&counts_mutex);
 201     n_nodes += n_nodes_local;
 202     n_updates += n_updates_local;
 203     n_nodes_removed += n_removed_local;
 204     qemu_mutex_unlock(&counts_mutex);
 205     return NULL;
 206 }
 207
 208 static void rcu_qtest_init(void)
 209 {
 210     struct list_element *new_el;
 211     int i;
 212     nthreadsrunning = 0;
 213     srand(time(0));
 214     for (i = 0; i < RCU_Q_LEN; i++) {
 215         new_el = g_new(struct list_element, 1);
 216         TEST_LIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry);
 217     }
 218     qemu_mutex_lock(&counts_mutex);
 219     n_nodes += RCU_Q_LEN;
 220     qemu_mutex_unlock(&counts_mutex);
 221 }
 222
 223 static void rcu_qtest_run(int duration, int nreaders)
 224 {
 225     int nthreads = nreaders + 1;
 226     while (atomic_read(&nthreadsrunning) < nthreads) {
 227         g_usleep(1000);
 228     }
 229
 230     atomic_set(&goflag, GOFLAG_RUN);
 231     sleep(duration);
 232     atomic_set(&goflag, GOFLAG_STOP);
 233     wait_all_threads();
 234 }
 235
 236
 237 static void rcu_qtest(const char *test, int duration, int nreaders)
 238 {
 239     int i;
 240     long long n_removed_local = 0;
 241
 242     struct list_element *el, *prev_el;
 243
 244     rcu_qtest_init();
 245     for (i = 0; i < nreaders; i++) {
 246         create_thread(rcu_q_reader);
 247     }
 248     create_thread(rcu_q_updater);
 249     rcu_qtest_run(duration, nreaders);
 250
 251     TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 252         TEST_LIST_REMOVE_RCU(prev_el, entry);
 253         call_rcu1(&prev_el->rcu, reclaim_list_el);
 254         n_removed_local++;
 255     }
 256     qemu_mutex_lock(&counts_mutex);
 257     n_nodes_removed += n_removed_local;
 258     qemu_mutex_unlock(&counts_mutex);
 259     synchronize_rcu();
 260     while (n_nodes_removed > n_reclaims) {
 261         g_usleep(100);
 262         synchronize_rcu();
 263     }
 264     if (g_test_in_charge) {
 265         g_assert_cmpint(n_nodes_removed, ==, n_reclaims);
 266     } else {
 267         printf("%s: %d readers; 1 updater; nodes read: "  \
 268                "%lld, nodes removed: %lld; nodes reclaimed: %lld\n",
 269                test, nthreadsrunning - 1, n_reads, n_nodes_removed, n_reclaims);
 270         exit(0);
 271     }
 272 }
 273
 274 static void usage(int argc, char *argv[])
 275 {
 276     fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]);
 277     exit(-1);
 278 }
 279
 280 static int gtest_seconds;
 281
 282 static void gtest_rcuq_one(void)
 283 {
 284     rcu_qtest("rcuqtest", gtest_seconds / 4, 1);
 285 }
 286
 287 static void gtest_rcuq_few(void)
 288 {
 289     rcu_qtest("rcuqtest", gtest_seconds / 4, 5);
 290 }
 291
 292 static void gtest_rcuq_many(void)
 293 {
 294     rcu_qtest("rcuqtest", gtest_seconds / 2, 20);
 295 }
 296
 297
 298 int main(int argc, char *argv[])
 299 {
 300     int duration = 0, readers = 0;
 301
 302     qemu_mutex_init(&counts_mutex);
 303     if (argc >= 2) {
 304         if (argv[1][0] == '-') {
 305             g_test_init(&argc, &argv, NULL);
 306             if (g_test_quick()) {
 307                 gtest_seconds = 4;
 308             } else {
 309                 gtest_seconds = 20;
 310             }
 311             g_test_add_func("/rcu/"TEST_NAME"/single-threaded", gtest_rcuq_one);
 312             g_test_add_func("/rcu/"TEST_NAME"/short-few", gtest_rcuq_few);
 313             g_test_add_func("/rcu/"TEST_NAME"/long-many", gtest_rcuq_many);
 314             g_test_in_charge = 1;
 315             return g_test_run();
 316         }
 317         duration = strtoul(argv[1], NULL, 0);
 318     }
 319     if (argc >= 3) {
 320         readers = strtoul(argv[2], NULL, 0);
 321     }
 322     if (duration && readers) {
 323         rcu_qtest(argv[0], duration, readers);
 324         return 0;
 325     }
 326
 327     usage(argc, argv);
 328     return -1;
 329 }