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 volatile 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
  86 struct list_element {
  87     QLIST_ENTRY(list_element) entry;
  88     struct rcu_head rcu;
  89 };
  90
  91 static void reclaim_list_el(struct rcu_head *prcu)
  92 {
  93     struct list_element *el = container_of(prcu, struct list_element, rcu);
  94     g_free(el);
  95     /* Accessed only from call_rcu thread.  */
  96     n_reclaims++;
  97 }
  98
  99 static QLIST_HEAD(q_list_head, list_element) Q_list_head;
 100
 101 static void *rcu_q_reader(void *arg)
 102 {
 103     long long n_reads_local = 0;
 104     struct list_element *el;
 105
 106     rcu_register_thread();
 107
 108     *(struct rcu_reader_data **)arg = &rcu_reader;
 109     atomic_inc(&nthreadsrunning);
 110     while (goflag == GOFLAG_INIT) {
 111         g_usleep(1000);
 112     }
 113
 114     while (goflag == GOFLAG_RUN) {
 115         rcu_read_lock();
 116         QLIST_FOREACH_RCU(el, &Q_list_head, entry) {
 117             n_reads_local++;
 118             if (goflag == GOFLAG_STOP) {
 119                 break;
 120             }
 121         }
 122         rcu_read_unlock();
 123
 124         g_usleep(100);
 125     }
 126     qemu_mutex_lock(&counts_mutex);
 127     n_reads += n_reads_local;
 128     qemu_mutex_unlock(&counts_mutex);
 129
 130     rcu_unregister_thread();
 131     return NULL;
 132 }
 133
 134
 135 static void *rcu_q_updater(void *arg)
 136 {
 137     int j, target_el;
 138     long long n_nodes_local = 0;
 139     long long n_updates_local = 0;
 140     long long n_removed_local = 0;
 141     struct list_element *el, *prev_el;
 142
 143     *(struct rcu_reader_data **)arg = &rcu_reader;
 144     atomic_inc(&nthreadsrunning);
 145     while (goflag == GOFLAG_INIT) {
 146         g_usleep(1000);
 147     }
 148
 149     while (goflag == GOFLAG_RUN) {
 150         target_el = select_random_el(RCU_Q_LEN);
 151         j = 0;
 152         /* FOREACH_RCU could work here but let's use both macros */
 153         QLIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 154             j++;
 155             if (target_el == j) {
 156                 QLIST_REMOVE_RCU(prev_el, entry);
 157                 /* may be more than one updater in the future */
 158                 call_rcu1(&prev_el->rcu, reclaim_list_el);
 159                 n_removed_local++;
 160                 break;
 161             }
 162         }
 163         if (goflag == GOFLAG_STOP) {
 164             break;
 165         }
 166         target_el = select_random_el(RCU_Q_LEN);
 167         j = 0;
 168         QLIST_FOREACH_RCU(el, &Q_list_head, entry) {
 169             j++;
 170             if (target_el == j) {
 171                 prev_el = g_new(struct list_element, 1);
 172                 n_nodes += n_nodes_local;
 173                 QLIST_INSERT_BEFORE_RCU(el, prev_el, entry);
 174                 break;
 175             }
 176         }
 177
 178         n_updates_local += 2;
 179         synchronize_rcu();
 180     }
 181     synchronize_rcu();
 182     qemu_mutex_lock(&counts_mutex);
 183     n_nodes += n_nodes_local;
 184     n_updates += n_updates_local;
 185     n_nodes_removed += n_removed_local;
 186     qemu_mutex_unlock(&counts_mutex);
 187     return NULL;
 188 }
 189
 190 static void rcu_qtest_init(void)
 191 {
 192     struct list_element *new_el;
 193     int i;
 194     nthreadsrunning = 0;
 195     srand(time(0));
 196     for (i = 0; i < RCU_Q_LEN; i++) {
 197         new_el = g_new(struct list_element, 1);
 198         QLIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry);
 199     }
 200     qemu_mutex_lock(&counts_mutex);
 201     n_nodes += RCU_Q_LEN;
 202     qemu_mutex_unlock(&counts_mutex);
 203 }
 204
 205 static void rcu_qtest_run(int duration, int nreaders)
 206 {
 207     int nthreads = nreaders + 1;
 208     while (atomic_read(&nthreadsrunning) < nthreads) {
 209         g_usleep(1000);
 210     }
 211
 212     goflag = GOFLAG_RUN;
 213     sleep(duration);
 214     goflag = GOFLAG_STOP;
 215     wait_all_threads();
 216 }
 217
 218
 219 static void rcu_qtest(const char *test, int duration, int nreaders)
 220 {
 221     int i;
 222     long long n_removed_local = 0;
 223
 224     struct list_element *el, *prev_el;
 225
 226     rcu_qtest_init();
 227     for (i = 0; i < nreaders; i++) {
 228         create_thread(rcu_q_reader);
 229     }
 230     create_thread(rcu_q_updater);
 231     rcu_qtest_run(duration, nreaders);
 232
 233     QLIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 234         QLIST_REMOVE_RCU(prev_el, entry);
 235         call_rcu1(&prev_el->rcu, reclaim_list_el);
 236         n_removed_local++;
 237     }
 238     qemu_mutex_lock(&counts_mutex);
 239     n_nodes_removed += n_removed_local;
 240     qemu_mutex_unlock(&counts_mutex);
 241     synchronize_rcu();
 242     while (n_nodes_removed > n_reclaims) {
 243         g_usleep(100);
 244         synchronize_rcu();
 245     }
 246     if (g_test_in_charge) {
 247         g_assert_cmpint(n_nodes_removed, ==, n_reclaims);
 248     } else {
 249         printf("%s: %d readers; 1 updater; nodes read: "  \
 250                "%lld, nodes removed: %lld; nodes reclaimed: %lld\n",
 251                test, nthreadsrunning - 1, n_reads, n_nodes_removed, n_reclaims);
 252         exit(0);
 253     }
 254 }
 255
 256 static void usage(int argc, char *argv[])
 257 {
 258     fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]);
 259     exit(-1);
 260 }
 261
 262 static int gtest_seconds;
 263
 264 static void gtest_rcuq_one(void)
 265 {
 266     rcu_qtest("rcuqtest", gtest_seconds / 4, 1);
 267 }
 268
 269 static void gtest_rcuq_few(void)
 270 {
 271     rcu_qtest("rcuqtest", gtest_seconds / 4, 5);
 272 }
 273
 274 static void gtest_rcuq_many(void)
 275 {
 276     rcu_qtest("rcuqtest", gtest_seconds / 2, 20);
 277 }
 278
 279
 280 int main(int argc, char *argv[])
 281 {
 282     int duration = 0, readers = 0;
 283
 284     qemu_mutex_init(&counts_mutex);
 285     if (argc >= 2) {
 286         if (argv[1][0] == '-') {
 287             g_test_init(&argc, &argv, NULL);
 288             if (g_test_quick()) {
 289                 gtest_seconds = 4;
 290             } else {
 291                 gtest_seconds = 20;
 292             }
 293             g_test_add_func("/rcu/qlist/single-threaded", gtest_rcuq_one);
 294             g_test_add_func("/rcu/qlist/short-few", gtest_rcuq_few);
 295             g_test_add_func("/rcu/qlist/long-many", gtest_rcuq_many);
 296             g_test_in_charge = 1;
 297             return g_test_run();
 298         }
 299         duration = strtoul(argv[1], NULL, 0);
 300     }
 301     if (argc >= 3) {
 302         readers = strtoul(argv[2], NULL, 0);
 303     }
 304     if (duration && readers) {
 305         rcu_qtest(argv[0], duration, readers);
 306         return 0;
 307     }
 308
 309     usage(argc, argv);
 310     return -1;
 311 }