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24#include <errno.h>
25#include <limits.h>
26#include <pthread.h>
27#include <stdio.h>
28#include <stdlib.h>
29#include <signal.h>
30#include <string.h>
31#include "atomic.h"
32#include "futextest.h"
33#include "logging.h"
34
35#define TEST_NAME "futex-requeue-pi"
36#define MAX_WAKE_ITERS 1000
37#define THREAD_MAX 10
38#define SIGNAL_PERIOD_US 100
39
40atomic_t waiters_blocked = ATOMIC_INITIALIZER;
41atomic_t waiters_woken = ATOMIC_INITIALIZER;
42
43futex_t f1 = FUTEX_INITIALIZER;
44futex_t f2 = FUTEX_INITIALIZER;
45futex_t wake_complete = FUTEX_INITIALIZER;
46
47
48static long timeout_ns;
49static int broadcast;
50static int owner;
51static int locked;
52
53struct thread_arg {
54 long id;
55 struct timespec *timeout;
56 int lock;
57 int ret;
58};
59#define THREAD_ARG_INITIALIZER { 0, NULL, 0, 0 }
60
61void usage(char *prog)
62{
63 printf("Usage: %s\n", prog);
64 printf(" -b Broadcast wakeup (all waiters)\n");
65 printf(" -c Use color\n");
66 printf(" -h Display this help message\n");
67 printf(" -l Lock the pi futex across requeue\n");
68 printf(" -o Use a third party pi futex owner during requeue (cancels -l)\n");
69 printf(" -t N Timeout in nanoseconds (default: 0)\n");
70 printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
71 VQUIET, VCRITICAL, VINFO);
72}
73
74int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg,
75 int policy, int prio)
76{
77 int ret;
78 struct sched_param schedp;
79 pthread_attr_t attr;
80
81 pthread_attr_init(&attr);
82 memset(&schedp, 0, sizeof(schedp));
83
84 ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
85 if (ret) {
86 error("pthread_attr_setinheritsched\n", ret);
87 return -1;
88 }
89
90 ret = pthread_attr_setschedpolicy(&attr, policy);
91 if (ret) {
92 error("pthread_attr_setschedpolicy\n", ret);
93 return -1;
94 }
95
96 schedp.sched_priority = prio;
97 ret = pthread_attr_setschedparam(&attr, &schedp);
98 if (ret) {
99 error("pthread_attr_setschedparam\n", ret);
100 return -1;
101 }
102
103 ret = pthread_create(pth, &attr, func, arg);
104 if (ret) {
105 error("pthread_create\n", ret);
106 return -1;
107 }
108 return 0;
109}
110
111
112void *waiterfn(void *arg)
113{
114 struct thread_arg *args = (struct thread_arg *)arg;
115 futex_t old_val;
116
117 info("Waiter %ld: running\n", args->id);
118
119
120
121 usleep(1000 * (long)args->id);
122
123 old_val = f1;
124 atomic_inc(&waiters_blocked);
125 info("Calling futex_wait_requeue_pi: %p (%u) -> %p\n",
126 &f1, f1, &f2);
127 args->ret = futex_wait_requeue_pi(&f1, old_val, &f2, args->timeout,
128 FUTEX_PRIVATE_FLAG);
129
130 info("waiter %ld woke with %d %s\n", args->id, args->ret,
131 args->ret < 0 ? strerror(errno) : "");
132 atomic_inc(&waiters_woken);
133 if (args->ret < 0) {
134 if (args->timeout && errno == ETIMEDOUT)
135 args->ret = 0;
136 else {
137 args->ret = RET_ERROR;
138 error("futex_wait_requeue_pi\n", errno);
139 }
140 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
141 }
142 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
143
144 info("Waiter %ld: exiting with %d\n", args->id, args->ret);
145 pthread_exit((void *)&args->ret);
146}
147
148void *broadcast_wakerfn(void *arg)
149{
150 struct thread_arg *args = (struct thread_arg *)arg;
151 int nr_requeue = INT_MAX;
152 int task_count = 0;
153 futex_t old_val;
154 int nr_wake = 1;
155 int i = 0;
156
157 info("Waker: waiting for waiters to block\n");
158 while (waiters_blocked.val < THREAD_MAX)
159 usleep(1000);
160 usleep(1000);
161
162 info("Waker: Calling broadcast\n");
163 if (args->lock) {
164 info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n", f2, &f2);
165 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
166 }
167 continue_requeue:
168 old_val = f1;
169 args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2, nr_wake, nr_requeue,
170 FUTEX_PRIVATE_FLAG);
171 if (args->ret < 0) {
172 args->ret = RET_ERROR;
173 error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
174 } else if (++i < MAX_WAKE_ITERS) {
175 task_count += args->ret;
176 if (task_count < THREAD_MAX - waiters_woken.val)
177 goto continue_requeue;
178 } else {
179 error("max broadcast iterations (%d) reached with %d/%d tasks woken or requeued\n",
180 0, MAX_WAKE_ITERS, task_count, THREAD_MAX);
181 args->ret = RET_ERROR;
182 }
183
184 futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
185
186 if (args->lock)
187 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
188
189 if (args->ret > 0)
190 args->ret = task_count;
191
192 info("Waker: exiting with %d\n", args->ret);
193 pthread_exit((void *)&args->ret);
194}
195
196void *signal_wakerfn(void *arg)
197{
198 struct thread_arg *args = (struct thread_arg *)arg;
199 unsigned int old_val;
200 int nr_requeue = 0;
201 int task_count = 0;
202 int nr_wake = 1;
203 int i = 0;
204
205 info("Waker: waiting for waiters to block\n");
206 while (waiters_blocked.val < THREAD_MAX)
207 usleep(1000);
208 usleep(1000);
209
210 while (task_count < THREAD_MAX && waiters_woken.val < THREAD_MAX) {
211 info("task_count: %d, waiters_woken: %d\n",
212 task_count, waiters_woken.val);
213 if (args->lock) {
214 info("Calling FUTEX_LOCK_PI on mutex=%x @ %p\n",
215 f2, &f2);
216 futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
217 }
218 info("Waker: Calling signal\n");
219
220 old_val = f1;
221 args->ret = futex_cmp_requeue_pi(&f1, old_val, &f2,
222 nr_wake, nr_requeue,
223 FUTEX_PRIVATE_FLAG);
224 if (args->ret < 0)
225 args->ret = -errno;
226 info("futex: %x\n", f2);
227 if (args->lock) {
228 info("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n",
229 f2, &f2);
230 futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
231 }
232 info("futex: %x\n", f2);
233 if (args->ret < 0) {
234 error("FUTEX_CMP_REQUEUE_PI failed\n", errno);
235 args->ret = RET_ERROR;
236 break;
237 }
238
239 task_count += args->ret;
240 usleep(SIGNAL_PERIOD_US);
241 i++;
242
243 if (i > MAX_WAKE_ITERS + THREAD_MAX) {
244 error("max signaling iterations (%d) reached, giving up on pending waiters.\n",
245 0, MAX_WAKE_ITERS + THREAD_MAX);
246 args->ret = RET_ERROR;
247 break;
248 }
249 }
250
251 futex_wake(&wake_complete, 1, FUTEX_PRIVATE_FLAG);
252
253 if (args->ret >= 0)
254 args->ret = task_count;
255
256 info("Waker: exiting with %d\n", args->ret);
257 info("Waker: waiters_woken: %d\n", waiters_woken.val);
258 pthread_exit((void *)&args->ret);
259}
260
261void *third_party_blocker(void *arg)
262{
263 struct thread_arg *args = (struct thread_arg *)arg;
264 int ret2 = 0;
265
266 args->ret = futex_lock_pi(&f2, NULL, 0, FUTEX_PRIVATE_FLAG);
267 if (args->ret)
268 goto out;
269 args->ret = futex_wait(&wake_complete, wake_complete, NULL,
270 FUTEX_PRIVATE_FLAG);
271 ret2 = futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG);
272
273 out:
274 if (args->ret || ret2) {
275 error("third_party_blocker() futex error", 0);
276 args->ret = RET_ERROR;
277 }
278
279 pthread_exit((void *)&args->ret);
280}
281
282int unit_test(int broadcast, long lock, int third_party_owner, long timeout_ns)
283{
284 void *(*wakerfn)(void *) = signal_wakerfn;
285 struct thread_arg blocker_arg = THREAD_ARG_INITIALIZER;
286 struct thread_arg waker_arg = THREAD_ARG_INITIALIZER;
287 pthread_t waiter[THREAD_MAX], waker, blocker;
288 struct timespec ts, *tsp = NULL;
289 struct thread_arg args[THREAD_MAX];
290 int *waiter_ret;
291 int i, ret = RET_PASS;
292
293 if (timeout_ns) {
294 time_t secs;
295
296 info("timeout_ns = %ld\n", timeout_ns);
297 ret = clock_gettime(CLOCK_MONOTONIC, &ts);
298 secs = (ts.tv_nsec + timeout_ns) / 1000000000;
299 ts.tv_nsec = ((int64_t)ts.tv_nsec + timeout_ns) % 1000000000;
300 ts.tv_sec += secs;
301 info("ts.tv_sec = %ld\n", ts.tv_sec);
302 info("ts.tv_nsec = %ld\n", ts.tv_nsec);
303 tsp = &ts;
304 }
305
306 if (broadcast)
307 wakerfn = broadcast_wakerfn;
308
309 if (third_party_owner) {
310 if (create_rt_thread(&blocker, third_party_blocker,
311 (void *)&blocker_arg, SCHED_FIFO, 1)) {
312 error("Creating third party blocker thread failed\n",
313 errno);
314 ret = RET_ERROR;
315 goto out;
316 }
317 }
318
319 atomic_set(&waiters_woken, 0);
320 for (i = 0; i < THREAD_MAX; i++) {
321 args[i].id = i;
322 args[i].timeout = tsp;
323 info("Starting thread %d\n", i);
324 if (create_rt_thread(&waiter[i], waiterfn, (void *)&args[i],
325 SCHED_FIFO, 1)) {
326 error("Creating waiting thread failed\n", errno);
327 ret = RET_ERROR;
328 goto out;
329 }
330 }
331 waker_arg.lock = lock;
332 if (create_rt_thread(&waker, wakerfn, (void *)&waker_arg,
333 SCHED_FIFO, 1)) {
334 error("Creating waker thread failed\n", errno);
335 ret = RET_ERROR;
336 goto out;
337 }
338
339
340
341 waiter_ret = &args[0].ret;
342 for (i = 0; i < THREAD_MAX; i++)
343 pthread_join(waiter[i],
344 *waiter_ret ? NULL : (void **)&waiter_ret);
345
346 if (third_party_owner)
347 pthread_join(blocker, NULL);
348 pthread_join(waker, NULL);
349
350out:
351 if (!ret) {
352 if (*waiter_ret)
353 ret = *waiter_ret;
354 else if (waker_arg.ret < 0)
355 ret = waker_arg.ret;
356 else if (blocker_arg.ret)
357 ret = blocker_arg.ret;
358 }
359
360 return ret;
361}
362
363int main(int argc, char *argv[])
364{
365 int c, ret;
366
367 while ((c = getopt(argc, argv, "bchlot:v:")) != -1) {
368 switch (c) {
369 case 'b':
370 broadcast = 1;
371 break;
372 case 'c':
373 log_color(1);
374 break;
375 case 'h':
376 usage(basename(argv[0]));
377 exit(0);
378 case 'l':
379 locked = 1;
380 break;
381 case 'o':
382 owner = 1;
383 locked = 0;
384 break;
385 case 't':
386 timeout_ns = atoi(optarg);
387 break;
388 case 'v':
389 log_verbosity(atoi(optarg));
390 break;
391 default:
392 usage(basename(argv[0]));
393 exit(1);
394 }
395 }
396
397 ksft_print_header();
398 ksft_print_msg("%s: Test requeue functionality\n", basename(argv[0]));
399 ksft_print_msg(
400 "\tArguments: broadcast=%d locked=%d owner=%d timeout=%ldns\n",
401 broadcast, locked, owner, timeout_ns);
402
403
404
405
406
407
408 ret = unit_test(broadcast, locked, owner, timeout_ns);
409
410 print_result(TEST_NAME, ret);
411 return ret;
412}
413
