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 <glib.h>
  25 #include "qemu/atomic.h"
  26 #include "qemu/rcu.h"
  27 #include "qemu/thread.h"
  28 #include "qemu/rcu_queue.h"
  29
  30 /*
  31  * Test variables.
  32  */
  33
  34 static QemuMutex counts_mutex;
  35 static long long n_reads = 0LL;
  36 static long long n_updates = 0LL;
  37 static long long n_reclaims = 0LL;
  38 static long long n_nodes_removed = 0LL;
  39 static long long n_nodes = 0LL;
  40 static int g_test_in_charge = 0;
  41
  42 static int nthreadsrunning;
  43
  44 #define GOFLAG_INIT 0
  45 #define GOFLAG_RUN  1
  46 #define GOFLAG_STOP 2
  47
  48 static volatile int goflag = GOFLAG_INIT;
  49
  50 #define RCU_READ_RUN 1000
  51 #define RCU_UPDATE_RUN 10
  52 #define NR_THREADS 100
  53 #define RCU_Q_LEN 100
  54
  55 static QemuThread threads[NR_THREADS];
  56 static struct rcu_reader_data *data[NR_THREADS];
  57 static int n_threads;
  58
  59 static int select_random_el(int max)
  60 {
  61     return (rand() % max);
  62 }
  63
  64
  65 static void create_thread(void *(*func)(void *))
  66 {
  67     if (n_threads >= NR_THREADS) {
  68         fprintf(stderr, "Thread limit of %d exceeded!\n", NR_THREADS);
  69         exit(-1);
  70     }
  71     qemu_thread_create(&threads[n_threads], "test", func, &data[n_threads],
  72                        QEMU_THREAD_JOINABLE);
  73     n_threads++;
  74 }
  75
  76 static void wait_all_threads(void)
  77 {
  78     int i;
  79
  80     for (i = 0; i < n_threads; i++) {
  81         qemu_thread_join(&threads[i]);
  82     }
  83     n_threads = 0;
  84 }
  85
  86
  87 struct list_element {
  88     QLIST_ENTRY(list_element) entry;
  89     struct rcu_head rcu;
  90 };
  91
  92 static void reclaim_list_el(struct rcu_head *prcu)
  93 {
  94     struct list_element *el = container_of(prcu, struct list_element, rcu);
  95     g_free(el);
  96     /* Accessed only from call_rcu thread.  */
  97     n_reclaims++;
  98 }
  99
 100 static QLIST_HEAD(q_list_head, list_element) Q_list_head;
 101
 102 static void *rcu_q_reader(void *arg)
 103 {
 104     long long n_reads_local = 0;
 105     struct list_element *el;
 106
 107     rcu_register_thread();
 108
 109     *(struct rcu_reader_data **)arg = &rcu_reader;
 110     atomic_inc(&nthreadsrunning);
 111     while (goflag == GOFLAG_INIT) {
 112         g_usleep(1000);
 113     }
 114
 115     while (goflag == GOFLAG_RUN) {
 116         rcu_read_lock();
 117         QLIST_FOREACH_RCU(el, &Q_list_head, entry) {
 118             n_reads_local++;
 119             if (goflag == GOFLAG_STOP) {
 120                 break;
 121             }
 122         }
 123         rcu_read_unlock();
 124
 125         g_usleep(100);
 126     }
 127     qemu_mutex_lock(&counts_mutex);
 128     n_reads += n_reads_local;
 129     qemu_mutex_unlock(&counts_mutex);
 130
 131     rcu_unregister_thread();
 132     return NULL;
 133 }
 134
 135
 136 static void *rcu_q_updater(void *arg)
 137 {
 138     int j, target_el;
 139     long long n_nodes_local = 0;
 140     long long n_updates_local = 0;
 141     long long n_removed_local = 0;
 142     struct list_element *el, *prev_el;
 143
 144     *(struct rcu_reader_data **)arg = &rcu_reader;
 145     atomic_inc(&nthreadsrunning);
 146     while (goflag == GOFLAG_INIT) {
 147         g_usleep(1000);
 148     }
 149
 150     while (goflag == GOFLAG_RUN) {
 151         target_el = select_random_el(RCU_Q_LEN);
 152         j = 0;
 153         /* FOREACH_RCU could work here but let's use both macros */
 154         QLIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 155             j++;
 156             if (target_el == j) {
 157                 QLIST_REMOVE_RCU(prev_el, entry);
 158                 /* may be more than one updater in the future */
 159                 call_rcu1(&prev_el->rcu, reclaim_list_el);
 160                 n_removed_local++;
 161                 break;
 162             }
 163         }
 164         if (goflag == GOFLAG_STOP) {
 165             break;
 166         }
 167         target_el = select_random_el(RCU_Q_LEN);
 168         j = 0;
 169         QLIST_FOREACH_RCU(el, &Q_list_head, entry) {
 170             j++;
 171             if (target_el == j) {
 172                 prev_el = g_new(struct list_element, 1);
 173                 n_nodes += n_nodes_local;
 174                 QLIST_INSERT_BEFORE_RCU(el, prev_el, entry);
 175                 break;
 176             }
 177         }
 178
 179         n_updates_local += 2;
 180         synchronize_rcu();
 181     }
 182     synchronize_rcu();
 183     qemu_mutex_lock(&counts_mutex);
 184     n_nodes += n_nodes_local;
 185     n_updates += n_updates_local;
 186     n_nodes_removed += n_removed_local;
 187     qemu_mutex_unlock(&counts_mutex);
 188     return NULL;
 189 }
 190
 191 static void rcu_qtest_init(void)
 192 {
 193     struct list_element *new_el;
 194     int i;
 195     nthreadsrunning = 0;
 196     srand(time(0));
 197     for (i = 0; i < RCU_Q_LEN; i++) {
 198         new_el = g_new(struct list_element, 1);
 199         QLIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry);
 200     }
 201     qemu_mutex_lock(&counts_mutex);
 202     n_nodes += RCU_Q_LEN;
 203     qemu_mutex_unlock(&counts_mutex);
 204 }
 205
 206 static void rcu_qtest_run(int duration, int nreaders)
 207 {
 208     int nthreads = nreaders + 1;
 209     while (atomic_read(&nthreadsrunning) < nthreads) {
 210         g_usleep(1000);
 211     }
 212
 213     goflag = GOFLAG_RUN;
 214     sleep(duration);
 215     goflag = GOFLAG_STOP;
 216     wait_all_threads();
 217 }
 218
 219
 220 static void rcu_qtest(const char *test, int duration, int nreaders)
 221 {
 222     int i;
 223     long long n_removed_local = 0;
 224
 225     struct list_element *el, *prev_el;
 226
 227     rcu_qtest_init();
 228     for (i = 0; i < nreaders; i++) {
 229         create_thread(rcu_q_reader);
 230     }
 231     create_thread(rcu_q_updater);
 232     rcu_qtest_run(duration, nreaders);
 233
 234     QLIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
 235         QLIST_REMOVE_RCU(prev_el, entry);
 236         call_rcu1(&prev_el->rcu, reclaim_list_el);
 237         n_removed_local++;
 238     }
 239     qemu_mutex_lock(&counts_mutex);
 240     n_nodes_removed += n_removed_local;
 241     qemu_mutex_unlock(&counts_mutex);
 242     synchronize_rcu();
 243     while (n_nodes_removed > n_reclaims) {
 244         g_usleep(100);
 245         synchronize_rcu();
 246     }
 247     if (g_test_in_charge) {
 248         g_assert_cmpint(n_nodes_removed, ==, n_reclaims);
 249     } else {
 250         printf("%s: %d readers; 1 updater; nodes read: "  \
 251                "%lld, nodes removed: %lld; nodes reclaimed: %lld\n",
 252                test, nthreadsrunning - 1, n_reads, n_nodes_removed, n_reclaims);
 253         exit(0);
 254     }
 255 }
 256
 257 static void usage(int argc, char *argv[])
 258 {
 259     fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]);
 260     exit(-1);
 261 }
 262
 263 static int gtest_seconds;
 264
 265 static void gtest_rcuq_one(void)
 266 {
 267     rcu_qtest("rcuqtest", gtest_seconds / 4, 1);
 268 }
 269
 270 static void gtest_rcuq_few(void)
 271 {
 272     rcu_qtest("rcuqtest", gtest_seconds / 4, 5);
 273 }
 274
 275 static void gtest_rcuq_many(void)
 276 {
 277     rcu_qtest("rcuqtest", gtest_seconds / 2, 20);
 278 }
 279
 280
 281 int main(int argc, char *argv[])
 282 {
 283     int duration = 0, readers = 0;
 284
 285     qemu_mutex_init(&counts_mutex);
 286     if (argc >= 2) {
 287         if (argv[1][0] == '-') {
 288             g_test_init(&argc, &argv, NULL);
 289             if (g_test_quick()) {
 290                 gtest_seconds = 4;
 291             } else {
 292                 gtest_seconds = 20;
 293             }
 294             g_test_add_func("/rcu/qlist/single-threaded", gtest_rcuq_one);
 295             g_test_add_func("/rcu/qlist/short-few", gtest_rcuq_few);
 296             g_test_add_func("/rcu/qlist/long-many", gtest_rcuq_many);
 297             g_test_in_charge = 1;
 298             return g_test_run();
 299         }
 300         duration = strtoul(argv[1], NULL, 0);
 301     }
 302     if (argc >= 3) {
 303         readers = strtoul(argv[2], NULL, 0);
 304     }
 305     if (duration && readers) {
 306         rcu_qtest(argv[0], duration, readers);
 307         return 0;
 308     }
 309
 310     usage(argc, argv);
 311     return -1;
 312 }