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