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