1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
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
31
32
33static QemuMutex counts_mutex;
34static long long n_reads = 0LL;
35static long long n_updates = 0LL;
36static int64_t n_reclaims;
37static int64_t n_nodes_removed;
38static long long n_nodes = 0LL;
39static int g_test_in_charge = 0;
40
41static int nthreadsrunning;
42
43#define GOFLAG_INIT 0
44#define GOFLAG_RUN 1
45#define GOFLAG_STOP 2
46
47static 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
54static QemuThread threads[NR_THREADS];
55static struct rcu_reader_data *data[NR_THREADS];
56static int n_threads;
57
58static int select_random_el(int max)
59{
60 return (rand() % max);
61}
62
63
64static 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
75static 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
89struct 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#elif TEST_LIST_TYPE == 3
95 QTAILQ_ENTRY(list_element) entry;
96#else
97#error Invalid TEST_LIST_TYPE
98#endif
99 struct rcu_head rcu;
100};
101
102static void reclaim_list_el(struct rcu_head *prcu)
103{
104 struct list_element *el = container_of(prcu, struct list_element, rcu);
105 g_free(el);
106
107 atomic_set_i64(&n_reclaims, n_reclaims + 1);
108}
109
110#if TEST_LIST_TYPE == 1
111static QLIST_HEAD(, list_element) Q_list_head;
112
113#define TEST_NAME "qlist"
114#define TEST_LIST_REMOVE_RCU QLIST_REMOVE_RCU
115#define TEST_LIST_INSERT_AFTER_RCU QLIST_INSERT_AFTER_RCU
116#define TEST_LIST_INSERT_HEAD_RCU QLIST_INSERT_HEAD_RCU
117#define TEST_LIST_FOREACH_RCU QLIST_FOREACH_RCU
118#define TEST_LIST_FOREACH_SAFE_RCU QLIST_FOREACH_SAFE_RCU
119
120#elif TEST_LIST_TYPE == 2
121static QSIMPLEQ_HEAD(, list_element) Q_list_head =
122 QSIMPLEQ_HEAD_INITIALIZER(Q_list_head);
123
124#define TEST_NAME "qsimpleq"
125#define TEST_LIST_REMOVE_RCU(el, f) \
126 QSIMPLEQ_REMOVE_RCU(&Q_list_head, el, list_element, f)
127
128#define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f) \
129 QSIMPLEQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
130
131#define TEST_LIST_INSERT_HEAD_RCU QSIMPLEQ_INSERT_HEAD_RCU
132#define TEST_LIST_FOREACH_RCU QSIMPLEQ_FOREACH_RCU
133#define TEST_LIST_FOREACH_SAFE_RCU QSIMPLEQ_FOREACH_SAFE_RCU
134
135#elif TEST_LIST_TYPE == 3
136static QTAILQ_HEAD(, list_element) Q_list_head;
137
138#define TEST_NAME "qtailq"
139#define TEST_LIST_REMOVE_RCU(el, f) QTAILQ_REMOVE_RCU(&Q_list_head, el, f)
140
141#define TEST_LIST_INSERT_AFTER_RCU(list_el, el, f) \
142 QTAILQ_INSERT_AFTER_RCU(&Q_list_head, list_el, el, f)
143
144#define TEST_LIST_INSERT_HEAD_RCU QTAILQ_INSERT_HEAD_RCU
145#define TEST_LIST_FOREACH_RCU QTAILQ_FOREACH_RCU
146#define TEST_LIST_FOREACH_SAFE_RCU QTAILQ_FOREACH_SAFE_RCU
147#else
148#error Invalid TEST_LIST_TYPE
149#endif
150
151static void *rcu_q_reader(void *arg)
152{
153 long long n_reads_local = 0;
154 struct list_element *el;
155
156 rcu_register_thread();
157
158 *(struct rcu_reader_data **)arg = &rcu_reader;
159 atomic_inc(&nthreadsrunning);
160 while (atomic_read(&goflag) == GOFLAG_INIT) {
161 g_usleep(1000);
162 }
163
164 while (atomic_read(&goflag) == GOFLAG_RUN) {
165 rcu_read_lock();
166 TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
167 n_reads_local++;
168 if (atomic_read(&goflag) == GOFLAG_STOP) {
169 break;
170 }
171 }
172 rcu_read_unlock();
173
174 g_usleep(100);
175 }
176 qemu_mutex_lock(&counts_mutex);
177 n_reads += n_reads_local;
178 qemu_mutex_unlock(&counts_mutex);
179
180 rcu_unregister_thread();
181 return NULL;
182}
183
184
185static void *rcu_q_updater(void *arg)
186{
187 int j, target_el;
188 long long n_nodes_local = 0;
189 long long n_updates_local = 0;
190 long long n_removed_local = 0;
191 struct list_element *el, *prev_el;
192
193 *(struct rcu_reader_data **)arg = &rcu_reader;
194 atomic_inc(&nthreadsrunning);
195 while (atomic_read(&goflag) == GOFLAG_INIT) {
196 g_usleep(1000);
197 }
198
199 while (atomic_read(&goflag) == GOFLAG_RUN) {
200 target_el = select_random_el(RCU_Q_LEN);
201 j = 0;
202
203 TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
204 j++;
205 if (target_el == j) {
206 TEST_LIST_REMOVE_RCU(prev_el, entry);
207
208 call_rcu1(&prev_el->rcu, reclaim_list_el);
209 n_removed_local++;
210 break;
211 }
212 }
213 if (atomic_read(&goflag) == GOFLAG_STOP) {
214 break;
215 }
216 target_el = select_random_el(RCU_Q_LEN);
217 j = 0;
218 TEST_LIST_FOREACH_RCU(el, &Q_list_head, entry) {
219 j++;
220 if (target_el == j) {
221 struct list_element *new_el = g_new(struct list_element, 1);
222 n_nodes += n_nodes_local;
223 TEST_LIST_INSERT_AFTER_RCU(el, new_el, entry);
224 break;
225 }
226 }
227
228 n_updates_local += 2;
229 synchronize_rcu();
230 }
231 synchronize_rcu();
232 qemu_mutex_lock(&counts_mutex);
233 n_nodes += n_nodes_local;
234 n_updates += n_updates_local;
235 atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local);
236 qemu_mutex_unlock(&counts_mutex);
237 return NULL;
238}
239
240static void rcu_qtest_init(void)
241{
242 struct list_element *new_el;
243 int i;
244 nthreadsrunning = 0;
245 srand(time(0));
246 for (i = 0; i < RCU_Q_LEN; i++) {
247 new_el = g_new(struct list_element, 1);
248 TEST_LIST_INSERT_HEAD_RCU(&Q_list_head, new_el, entry);
249 }
250 qemu_mutex_lock(&counts_mutex);
251 n_nodes += RCU_Q_LEN;
252 qemu_mutex_unlock(&counts_mutex);
253}
254
255static void rcu_qtest_run(int duration, int nreaders)
256{
257 int nthreads = nreaders + 1;
258 while (atomic_read(&nthreadsrunning) < nthreads) {
259 g_usleep(1000);
260 }
261
262 atomic_set(&goflag, GOFLAG_RUN);
263 sleep(duration);
264 atomic_set(&goflag, GOFLAG_STOP);
265 wait_all_threads();
266}
267
268
269static void rcu_qtest(const char *test, int duration, int nreaders)
270{
271 int i;
272 long long n_removed_local = 0;
273
274 struct list_element *el, *prev_el;
275
276 rcu_qtest_init();
277 for (i = 0; i < nreaders; i++) {
278 create_thread(rcu_q_reader);
279 }
280 create_thread(rcu_q_updater);
281 rcu_qtest_run(duration, nreaders);
282
283 TEST_LIST_FOREACH_SAFE_RCU(prev_el, &Q_list_head, entry, el) {
284 TEST_LIST_REMOVE_RCU(prev_el, entry);
285 call_rcu1(&prev_el->rcu, reclaim_list_el);
286 n_removed_local++;
287 }
288 qemu_mutex_lock(&counts_mutex);
289 atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local);
290 qemu_mutex_unlock(&counts_mutex);
291 synchronize_rcu();
292 while (atomic_read_i64(&n_nodes_removed) > atomic_read_i64(&n_reclaims)) {
293 g_usleep(100);
294 synchronize_rcu();
295 }
296 if (g_test_in_charge) {
297 g_assert_cmpint(atomic_read_i64(&n_nodes_removed), ==,
298 atomic_read_i64(&n_reclaims));
299 } else {
300 printf("%s: %d readers; 1 updater; nodes read: " \
301 "%lld, nodes removed: %"PRIi64"; nodes reclaimed: %"PRIi64"\n",
302 test, nthreadsrunning - 1, n_reads,
303 atomic_read_i64(&n_nodes_removed), atomic_read_i64(&n_reclaims));
304 exit(0);
305 }
306}
307
308static void usage(int argc, char *argv[])
309{
310 fprintf(stderr, "Usage: %s duration nreaders\n", argv[0]);
311 exit(-1);
312}
313
314static int gtest_seconds;
315
316static void gtest_rcuq_one(void)
317{
318 rcu_qtest("rcuqtest", gtest_seconds / 4, 1);
319}
320
321static void gtest_rcuq_few(void)
322{
323 rcu_qtest("rcuqtest", gtest_seconds / 4, 5);
324}
325
326static void gtest_rcuq_many(void)
327{
328 rcu_qtest("rcuqtest", gtest_seconds / 2, 20);
329}
330
331
332int main(int argc, char *argv[])
333{
334 int duration = 0, readers = 0;
335
336 qemu_mutex_init(&counts_mutex);
337 if (argc >= 2) {
338 if (argv[1][0] == '-') {
339 g_test_init(&argc, &argv, NULL);
340 if (g_test_quick()) {
341 gtest_seconds = 4;
342 } else {
343 gtest_seconds = 20;
344 }
345 g_test_add_func("/rcu/"TEST_NAME"/single-threaded", gtest_rcuq_one);
346 g_test_add_func("/rcu/"TEST_NAME"/short-few", gtest_rcuq_few);
347 g_test_add_func("/rcu/"TEST_NAME"/long-many", gtest_rcuq_many);
348 g_test_in_charge = 1;
349 return g_test_run();
350 }
351 duration = strtoul(argv[1], NULL, 0);
352 }
353 if (argc >= 3) {
354 readers = strtoul(argv[2], NULL, 0);
355 }
356 if (duration && readers) {
357 rcu_qtest(argv[0], duration, readers);
358 return 0;
359 }
360
361 usage(argc, argv);
362 return -1;
363}
364
